U.S.S. ASPRO (SS-309) — war patrol report SS-309_ASPRO.pdf

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START OF REEL
JOB NO. [HANDWRITTEN: H-108-AR-149-76]
[HANDWRITTEN: R#1]

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4.5 | 2.8 | 2.5
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OPERATOR [HANDWRITTEN: HANCOCK]

DATE [HANDWRITTEN: 11-19-75]

THIS MICROFILM IS
THE PROPERTY OF
THE UNITED STATES
GOVERNMENT

[SEAL: DEPARTMENT OF DEFENSE, UNITED STATES OF AMERICA, with eagle emblem]

MICROFILMED BY
NPPSO-NAVAL DISTRICT WASHINGTON
MICROFILM SECTION

REEL TARGET, START & END
NAVEXOS 3968

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Division of Naval History
Ships' Histories Section
Navy Department

HISTORY OF USS ASPRO (SS 309)

USS ASPRO, veteran of seven war patrols sank over 50,000
tons of Japanese shipping in addition to performing daring feats
during World War II. More than three months before American forces
landed on the Island of Luzon, USS ASPRO ran aground just off
shore while trying to fire at two enemy cargo ships. She barely
escaped by surfacing with what seemed like half the Japanese air
force overhead while several enemy patrol craft were searching
frantically nearby.

ASPRO later went inside Tokyo Bay to rescue a pilot who had
been shot down. This daring rescue was conducted in broad day-
light with Japanese aircraft straffing both the submarine and the
pilot's life boat.

ASPRO's varied career began at the Portsmouth, New Hampshire
Navy Yard where her keel was laid on 27 December 1942. The sub-
marine was launched on 7 April 1943 with Mrs. William L. Freseman,
wife of Commander William L. Freseman, USN, acting as sponsor.

On 31 July 1943, USS ASPRO was commissioned with Lieutenant
Commander H. C. Stevenson, USN, as her first commanding officer.
The submarine was fitted out at Portsmouth, after which she sailed
to New London, Connecticut to conduct trial runs and tests.
After all tests were successfully completed, she sailed for Pearl
Harbor, T. H. on 17 September 1943. Arriving at Pearl Harbor on
18 October 1943, ASPRO provisioned in preparation for her first
war patrol.

On 24 November she turned her bow west once more and sailed
for Midway Island where she arrived on 28 November to complete
the loading of provisions and fuel. She departed again the same
day enroute to her patrol area in the East China Sea around the
island of Formosa. On 4 December ASPRO sighted a sampan of about
100 tons and closed to attack with her deck guns. Only one hit
was scored before the sampan opened up with small caliber fire and
another sampan came up to assist. Apparently outgunned at close
range and unable to see the target at long range, ASPRO broke off
the attack.

On 15 December a convoy of three ships, a tanker in the center
of two freighters, with an escorting destroyer escort ahead and
astern was sighted. Four torpedoes were fired and a moment later
an explosion was heard. Depth charges then came raining down and
ASPRO went deep to elude the angry escorts.

On 17 December contact was made on another convoy and ASPRO
began an end around to get into position for an attack. The target
turned out to be a large convoy of tankers and freighters and at
2225 ASPRO began firing her bow tubes. One minute later the stern

— page 3 —
-2- USS ASPRO (SS 309)

tubes were fired at a large tanker and adjacent freighter transport
which was overlapping the tanker astern. A moment later a series
of underwater explosions commenced that lasted for about 15 to 20
minutes. At 2230 the transport sank bow first with her siren and
whistle still blowing for aid that never arrived. One minute later
a medium sized freighter went down with about a 15 degree bow
angle, her screws going high into the air. Less than a minute later
another medium freighter rolled over to her starboard side, lay
suspended there a moment and then sank.

A tanker astern of ASPRO settled in the water and went down
by the bow until her decks were awash. It was believed she was
sinking. However, a few moments later a small ship was seen tow-
ing her.

Completing a reload, ASPRO noted that the convoy had
scattered to the eastward except for the group of four freighters
and two escorts. On 18 December ASPRO fired three bow tubes at
a freighter in the center of the convoy and three bow tubes at
an overlapping freighter to the right and ahead of the first.
One minute later the entire convoy was silhouetted by a giant, orange
colored explosion from the target. As ASPRO started diving deep,
four torpedo explosions were heard. No further damage could be
observed as the depth charges began thumping, forcing ASPRO to go
deep.

On 20 December ASPRO started the long voyage back to Midway
Island. Christmas dinner was celebrated submerged while enroute.
However, ASPRO's patrol wasn't over yet, for on 27 December four
torpedoes were fired at a ship and a moment later five explosions
were heard at 20 second intervals. No other contacts were made
and ASPRO concluded her first war patrol when she moored at Midway
on 1 January 1944.

ASPRO underwent a two week refit during which time she had
a change of command. On 15 January 1944, Lieutenant Commander
W. A. Stevenson, USN, relieved his brother, Commander H. C.
Stevenson, USN, as commanding officer. On 18 January ASPRO sailed
for Pearl Harbor and arrived there on the 22nd, to conduct train-
ing exercises in preparation for her second war patrol.

ASPRO departed Pearl Harbor on 3 February, stopped briefly
at Midway Island to take on fuel and stores, before sailing for
her patrol area north of Truk Island. While submerged on 15 Feb-
ruary, a Japanese submarine, AI-43, was sighted which headed for
Truk at full speed. Being unable to close him submerged, ASPRO
surfaced at long range and watched him until dark through the
periscope. As darkness settled ASPRO started a radar approach and
several hours later, two torpedoes ended the career of the unsus-
pecting Japanese submarine.

— page 4 —
-3- USS ASPRO (SS 309)

On 4 March, a large passenger freighter or tender was sighted
and a night surface attack was made. One torpedo hit but later
attempts to attack that target were prevented due to the accurate
firing of her alert gun crews. The remainder of the patrol was
spent on life guard duty while American pilots were bombing Truk.
The patrol terminated on 28 March when the submarine put in at
Pearl Harbor for a refit.

ASPRO's third war patrol was held in the vicinity of Palau
Island. She departed Pearl Harbor on 21 April and arrived at
Midway Island for supplies on the 25th.

On 13 May the stacks of two ships were sighted near a reef
and ASPRO began her approach. However, the approach had to be
broken off when it was found that the freighters were too near
the reefs to afford the submarine a good attack position. The
following day the same two ships were again sighted and again
ASPRO began maneuvering for an attack position. At this time an
escort heretofore unseen, bore down on her, forcing her to fire at
the escort before the attack could be set up. Both torpedoes were
heard to explode at the end of their run.

By 0518 ASPRO had made an end around and was in a perfect
set up with a freighter on either side. Shortly after, four
torpedoes went streaking on their way and one struck home. However,
ASPRO did not stay around long enough to observe the damage as she
went deep and rigged for a depth charging. The escorts failed
to locate her though, and a few moments later, the submarine came
to periscope depth and began tracking the remaining target.

Early on the morning of 15 May ASPRO gained her attack ad-
vantage and fired four torpedoes at the remaining freighter. Two
of the torpedoes struck home as the submarine went deep to avoid
the inevitable depth charging. Upon coming to periscope depth
again a little later the target was seen settling in the water
and as ASPRO began closing to finish the MARU off with her deck
gun, a loud explosion occurred on the target which sank her
immediately. It was thought that a friendly submarine had slipped
up on the target's disengaged side and finished her off with a well
aimed torpedo. On 4 June USS ASPRO was ordered to proceed to
Fremantle, Australia for a refit. She crossed the equator on 8
June and arrived at Fremantle on the 16th.

Underway for her fourth war patrol on 9 July, ASPRO stopped
briefly at Darwin, Australia then sailed on enroute to her patrol
area in the China Sea off Luzon.

Her first contact was made on 18 July and after several
tracking exercises throughout that day and the next, ASPRO gained
an attack position at dawn on 19 July. The convoy consisted of
four ships and at 0545 ASPRO fired four bow tubes at the second
MARU then shifted her attention to the third ship and fired the
two remaining bow tubes. She then swung to starboard to bring her
stern tubes to bear.

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-4- USS ASPRO (SS 309)

Before the turn was completed her torpedoes began striking
home. Two explosions on the first target completely blotted out
the first target but the second target had neatly changed course
and avoided the torpedoes fired at him. ASPRO then fired four
more torpedoes from her stern tubes, then went deep and rigged
for depth charges. Just as she hit the deeper depths three torpedo
explosions were heard, then the depth charges began raining down
though none were very near.

After experiencing trouble with one of her engines which
cut her top speed to 17 knots, ASPRO sighted smoke on 20 July
and closed for an attack. The target was identified as a medium
freighter of about 4000 tons with two escorts. Four torpedoes were
fired down the freighters throat and though no explosions were
heard, it was possible that one torpedo hit for a quick look through
the periscope before going deep showed the target covered with
spray. ASPRO went deep and rigged for a depth charging which came
in short order. All hands welcomed a temperature gradiant which
let the escort ping in vain though 31 depth charges came down
right on top of the submarine but exploded before they gained her
depth, thanks to the temperature gradiant which caused the error
in the escort anti-submarine problem.

On 28 July ASPRO sighted a freighter anchored about 600
yards off shore from Luzon. Closing the range she fired three
torpedoes all of which hit with devastating effect. The ship
burned like an inferno while all hands aboard ASPRO were allowed
to take a look through the periscope. On 4 August ASPRO returned
to the scene and found the target completely gutted by fires,
rusted from stem to stern with two holes, one under the stack and
one in the bow, from the hits and hard aground. It was decided
another torpedo could not inflict more destruction so she surfaced
and cleared the area.

On 6 August two freighters were sighted and attacked on 7
August with ASPRO's last four torpedoes. One ship was definitely
sunk and two others believed to be damaged. However, the submarine
took no chances in staying around the heavily guarded convoy with-
out the benefit of more torpedoes. She then departed the area
enroute to Fremantle, Australia for a refit. She arrived in the
"land down under" on 18 August 1944.

On 10 September ASPRO departed Fremantle enroute to her patrol
area for her fifth war patrol. On 20 September a sampan was hailed
after a few bursts of 20 millimeter fire across her bow, but it
contained only a half-dozen scared natives. They could speak no
English so ASPRO provided them with bread, cigarettes, and other
supplies, and parted good friends. Another sampan was hailed on
23 September with much the same results.

On 30 September an eight-ship convoy with escorts was sighted
and ASPRO fired six torpedoes at a large freighter. Two hits were
heard as she went deep and a little later breaking up noises were
heard.

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-5- USS ASPRO (SS 309)

On 1 October two more marus were sighted and ASPRO attacked
one of the freighters with three torpedoes. While maneuvering to
fire on the other maru, she grounded and though she freed herself
once, she hit bottom again and that time she stuck fast. A plane
was circling overhead, dropping depth charges and as efforts to
unground were unsuccessful, the commanding officer decided to
take a chance. As ASPRO shot to the surface the plane made a
gliding attack, forcing the submarine down again. This time she
went to 50 feet and the bomb hit some distance away causing no
damage. She then cleared the area in search of deep water to find
out how much damage had been done.

The result of this grounding caused ASPRO's crew to boast of
being the "first amphibious assault on the Island of Luzon" and to
call the ship itself the USS ASPRO, L.C.S.: "Landing Craft Sub-
mersible."

The following day ASPRO again contacted the two Japanese
freighters and closed for an attack again. At 0846 she fired four
torpedoes from her bow tubes for three hits. A brief glimpse
through the periscope showed the tanker with her bow in the air at
a 70 degree angle. At 0920, while the other maru was picking up
survivors. ASPRO maneuvered into position for a stern tube shot
and fired three torpedoes at her. Two torpedo explosions were
heard before the air cover began dropping bombs at the submarine.
A quick glimpse through the periscope showed the maru slightly
down by the stern though she still had way on. However, another
attack was not advisable as ASPRO's batteries were very low and
she had long since worn out her welcome in that area.

Late that night she rendezvoused with the submarine USS
CABRILLA and received orders to patrol the area north of Dili
Point the following day. The following day a large single freighter
was sighted which turned out to be the one ASPRO had damaged the
day before. Two torpedoes still failed to finish the enemy ship
so ASPRO maneuvered to fire once more. The torpedo hit slightly
aft but after an observation it still did not appear to be sink-
ing fast enough. Another shot was fired but just as it cleared
the tubes the stern went down, throwing the bow high into the air,
thus the last torpedo was not needed.

October 6th brought sight of another convoy and ASPRO began
tracking for a shot at the largest ship. However, an alert escort
forced ASPRO to go deep and by the time she surfaced again the con-
voy was to seaward of her. Upon surfacing at 0828 a tanker was so
close that he screened the entire convoy from the submarine. ASPRO
picked a tanker for her first target as she readied all torpedo
tubes. Three torpedoes went streaking after her and two were
heard to hit. The next look showed the tanker had dis-appeared as
ASPRO readied her torpedoes for another attack.

— page 7 —
-6- USS ASPRO (SS 309)

However, USS HOE contacted ASPRO before she could get off
another shot and it was decided that HOE, ASPRO and CABRILLA would
make a coordinate attack on a large convoy a little farther south
of ASPRO's position. HOE attacked first then ASPRO fired four
torpedoes and observed three hits on a large freighter. That was
the end of ASPRO's torpedo supply so she dropped behind the convoy
and tracked it until USS HOE was contacted then headed for "home"
to replenish her torpedo supply.

ASPRO rendezvoused with USS WHALE on 9 October to remove a
patient, dropping him at Saipan on 14 October. On 16 October she
sailed on to Pearl Harbor, arriving there on the 25th.

After a normal refit at Pearl Harbor, ASPRO sailed on her
sixth war patrol. An accident to a main generator caused her to
return to Pearl Harbor on 3 December. After repairs she departed
again for a patrol area on 13 December. This time she was part
of a coordinated attack group consisting of ASPRO, SAWFISH, and
CROAKER. In her first torpedo attack a convoy of two large freighter
transports with three escorts was picked up by radar and tracked
until dawn on 2 January 1945. A favorable zig by the target
placed ASPRO in an excellent firing position from which six tor-
pedoes were fired at a range of 900 yards. Immediately after
firing the first torpedo a report was received that the torpedo
was running hot in the tube. Firing was ordered continued and re-
sulted in one timed hit and four hot runs in the tubes. After
the depth charge counter attack, ejecting the expended torpedoes
presented quite a problem which was solved only after considerable
difficulty.

On 5 January 1945 a large damaged tanker, dead in the water,
with one escort making a poor job of defending, was picked up by
radar. By approaching the off side, ASPRO was able to make an
attack in which four torpedoes were fired for two hits. The tanker
was severely damaged by two terrific explosions and sank about
15 minutes later while another approach was being made.

On 21 January a raft with three aviators aboard was sighted
and all three were rescued in good condition, though they were
inside restricted waters. A second life raft was found a little
later and two more aviators rescued. One, Lieutenant (j.g.) Colley
from USS LEXINGTON had been in the water for approximately four
hours, half of that time without the benefit of a raft. He had
been wounded in the leg when his plane was hit and had swallowed
considerable salt water. All injuries responded to treatment.

On 2 February ASPRO put into Tanapag Harbor to transfer
personnel, fuel, and take on a fresh load of torpedoes. The fol-
lowing day she sailed for Pearl Harbor, arriving on 11 February
1945.

Departing Pearl Harbor, ASPRO sailed for San Francisco for
a Navy Yard overhaul. She arrived on 20 February 1945, and re-
mained there until 31 May. At San Francisco, Commander J. H.

— page 8 —
-7- USS ASPRO (SS 309)

Ashley, Jr., USN, relieved Commander W. A. Stevenson, USN, as
commanding officer.

Departing San Francisco on 2 June, ASPRO arrived in Pearl
Harbor on 10 June. On the 25th, she headed her bow westward on
her seventh and last war patrol. This last patrol was conducted
in Empire waters off Eastern Honshu, the Tokyo lifeguard station
area. All but three days of the patrol were spent in lifeguard
duty.

ASPRO made her first rescue of the patrol on 8 July when she
picked up flight John E. Freeman, USA, up at 1517. He was later
transferred by rubber boat to USS RUNNER.

On 25 July a tug towing a dredge and two steam launches with
a work barge in tow were sighted. As this was the first ship seen
on the patrol, it was decided to attack the larger tug. At 0618
two torpedoes went on their way, one striking amidships tearing a
large hole in the side under the stack. ASPRO's commanding officer
took pictures as the target rolled over and sank, keel up. ASPRO
then headed for her life guard station for the raids scheduled
against Honshu that night.

On 3 August ASPRO received word that an Army pilot was down
inside Sagami Nada and a B-17 was sent to investigate. Another
plane was sent a little later just as the first reported he had
dropped a wooden boat and was circling the pilot. ASPRO's com-
manding officer put on four-engine speed and headed in even as though
it were broad daylight.

The pilot was not faring so well. As the lifeboat's motor
began operating, four Japanese Zekes strafed him. The frail craft
was riddled but the pilot suffered only a grazed wrist. U. S.
Navy patrol bombers finally drove away the enemy fighter planes.

Meanwhile ASPRO was having trouble of her own. She had been
sighted by four friendly fighter planes which circled overhead as
escorts. These planes had hardly finished signaling that they
were low on fuel and would soon have to leave when four Zekes
attacked them. They drove the enemy planes away, however, before
departing the scene.

As ASPRO spotted the life boat, all available speed was put
on the line for the run in. ASPRO was only seven miles off the
beach, 35 miles from Tokyo and 20 miles from Yokohama, and feeling
awfully naked riding on the surface in the noon-day sun. The
downed aviator saw the exhaust of the submarine and headed in that
direction.

Just as his boat drew up aft of ASPRO a Japanese float plane
started a glide bombing run on the submarine. ASPRO's guns were
manned and they took the plane under fire. One gun scored a few
hits in the enemy's wing and the plane sprayed ASPRO with machine
gun fire. ASPRO dove in what was probably the fastest dive of her
career, leaving the disheartened aviator, but only temporarily.

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-8- USS ASPRO (SS 309)

Just as the captain of ASPRO raised his periscope for a look,
the plane let go with two bombs, both very close. Cork was knocked
off the bulkheads, the ship took a sharp angle down and in the
torpedo rooms men were thrown about and smashed light bulbs littered
the entire ship.

Suddenly a pair of B-24 bombers appeared out of nowhere and
pursued the Japanese shooting him down about a mile away. ASPRO
surfaced and again headed in but another enemy plane appeared.
Two more bombs fell close by and mauled the submarine slightly as
she went down again.

With plenty of intestinal fortitude Commander Ashley raised
his periscope, then surfaced and came to a stop. The pilot started
toward the submarine and upon coming alongside shut the throttle
of his boat and jumped on the bow of his boat where two of the
submariners grabbed him and hauled him aboard. Very excited, the
pilot began turning the wrong way when he was stopped by his
rescuers and practically thrown down a hatch. Submerging, ASPRO
made a successful getaway, while down below, the Army pilot was
taking a hot shower, switching into clean clothes and preparing for
a long sleep. ASPRO had thus performed one of the more
spectacular rescue missions of the war.

USS ASPRO terminated her seventh war patrol on 13 August
1945 when she put in at Midway Island for a refit. On 1 September
she departed Midway enroute to San Francisco, California. ASPRO
arrived on 11 September 1945, to undergo preservation work prior
to being placed out of commission in reserve to the San Francisco
Group, Pacific Reserve Fleet, by a directive of January 1947.

USS ASPRO (SS 309) was awarded the Navy Unit Commendation
for her first and second war patrols. The citation follows:

"For outstanding heroism in action against enemy
Japanese shipping and a combatant unit, during her
First War Patrol east of Formosa, from November 24,
1943, to January 1, 1944, and her Second War Patrol
north of Truk, from February 3 to March 24, 1944.
Aggressive and tenacious, in pursuit of possible
targets, the U.S.S. ASPRO relentlessly tracked enemy
contacts, often into dangerously shallow coastal
waters, and struck boldly at several large enemy
convoys. Despite harassing anti-submarine measures,
she skillfully penetrated heavy air and surface screens,
pressed home the attack and sunk four enemy ships, in-
cluding a prize I-Class Submarine, for a total of
14,200 tons, and damaged five other vessels totalling
20,000 tons. The superb seamanship and steadfast
devotion to duty of her officers and men reflect the
highest credit upon her self and the United States
Naval Service."

— page 10 —
-9- USS ASPRO (SS 309)

In addition, USS ASPRO earned eight Battle Stars on the
Asiatic-Pacific Area Service Medal for participating in the
following operations:

1 Star/Anti-submarine Assessment -- 15 February 1944
1 Star/Asiatic-Pacific Raids -- 1944
    Truk Attack -- 16 and 17 February 1944
1 Star/Western New Guinea Operations
    Noemfoor Island Operation -- 9 to 23 July 1944
1 Star/Luzon Operation
    Lingayen Gulf Landing -- 13 December 1944 to 11 February
    1945
1 Star/THIRD Fleet Operations against Japan -- 10 July to 6 August
    1945
1 Star/Submarine War Patrol -- 24 November 1943 to 1 January 1944
1 Star/Submarine War Patrol -- 22 April to 16 June 1944
1 Star/Submarine War Patrol -- 10 May to 25 October 1944

* * * * * * *

STATISTICS

OVERALL LENGTH                 312 feet
BEAM                           27 feet
SPEED                          20 knots
DISPLACEMENT                   1,465 tons

* * * * * *

NOTE: Estimates of sinkings, tonnage, and types sunk are taken
      from the commanding officer's evaluations during war
      patrols.

Compiled: December 1952

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[HANDWRITTEN: 1ST COPY]
1 02184

SS309/A16-3
Serial 01-44

[FADED TEXT, likely part of a classification, e.g., CONFIDENTIAL] FIDENTIAL
[STAMP: DECLASSIFIED]

U.S.S. ASPRO (SS309)
%Fleet Post Office,
San Francisco, Calif.,
1 January, 1943.

From: The Commanding Officer.
To : ✓ The Commander in Chief, United States Fleet.
Via : The Commander in Chief, U.S. Pacific Fleet.
The Commander Submarine Force, Pacific Fleet.
The Commander Submarine Squadron
The Commander Submarine Division 201.

Subject: U.S.S. ASPRO, Report of War Patrol Number One.

Enclosure: [HANDWRITTEN: ✓] (A) Subject Report.
(B) Track Chart (Comsubpac).

1. Enclosure (A), covering the first war patrol of this
ship conducted in the waters around Taiwan and Sakishima Gunto, during
the period from 24 November, 1943 to 1 January, 1944, is forwarded
herewith.

[SIGNATURE: H.C. Stevinson]
H.C. STEVINSON.

[HANDWRITTEN: 5]

— page 13 —
ENCLOSURE (A)

CONFIDENTIAL

(A) PROLOGUE
                                                                1 02184

        Arrived Pearl Harbor, T.H., on October 18, 1943 from the East
Coast of the United States and departed on the first war patrol
on November 24, 1943. The intervening time was utilized in repair-
ing a leaking maneuvering room hard patch, the installation of a
PPI radar, and in training.

(B) NARRATIVE

24-28 November, 1943

        At 1300 (VW) departed Pearl Harbor for Midway with PC 597 as
escort. At 1915 (VW) released escort and proceeded independently.
Conducted training enroute. Contacted air escort at 0900 (Y) and
moored at Midway at 1115 (Y) November 28, 1943. Took on fuel,
lub oil, and stores at Midway, and at 1600 (Y) departed for patrol
area under air coverage.

29 November, 1943

0830 (Y) Crossed 180th Meridian.

2 December, 1943

0830(K) Sighted a U.S. Submarine ahead on opposite and parallel course
        and distant about 5 miles. She was likely the U.S.S. SARGO.
        Submarine dove prior to any attempt to exchange recognition signals.
        Altered course to go around and when clear resumed course to area.

4 December, 1943

1840(K) Sighted a steady white light bearing 000°T. Altered course to
        investigate. Radar picked up target at 10,100 yards. Target was
        sighted from bridge at 6000 yards range and proved to be a sampan of
        about 100 tons, net fishing with all lights burning. Decided to go
        around and attack from the dark area of moon with the deck gun.

2046(K) Commenced firing at 3000 yards range using H.E. point detonating
        ammunition. The second salvo hit forward of sampan deck house near
        water line. Sampan then extinguished her lights and gun pointers
        were unable to see target. Attempted firing by setting TBT bearings
        on gun azimuth and pointing at horizon. Closed to 1700 yards range
        with sampan returning fire with ineffective small caliber machine gun

                                - 1 -
[HANDWRITTEN: 6]

— page 14 —
bursts. At this point sampan opened up with a larger gun,
possibly a 20 m.m. or its equivalent or even larger. Another
sampan was sighted ahead and closing rapidly. Decided to
break off engagement when the sampan got range and shells
were coming close and spent machine gun bullets hit
superstructure aft. (No damage sustained.) We were apparently
outgunned at close ranges and could not see at longer ranges.
Eight rounds were fired with one hit. Retired at high speed
until clear and resumed course and speed to area. Lat. 27-
46 N., Long. 156-16 E.

5 December, 1943

1710(J) Obtained radar interference on Sail Dog radar. This
interference continued for approximately an 800 mile run and
seemed to center in Bonins.

8 December, 1943

1119(J) Weather overcast, visibility 6000 yards. Sighted sampan
bearing 167°T. Made quick dive. Heavy seas would obviate
a battle surface and did not wish to be sighted. We were
probably sighted.

1337(J) Surfaced. Well clear of sampan.

1347(J) Sighted patrol boat, similar to our PC boats, ahead, angle
on bow zero, range 7000 yards. Made quick dive and altered
course to evade. Possibly sampan sent in contact report.

1638(J) Surfaced. Nothing in sight.

2335(I) SJ radar out of commission. Sighted sampan bearing 250° T
distant 2500 yards. Turned away and avoided on surface.
Resumed course at 2352(I)

9 December, 1943

0640(I) SJ radar in commission. Tube had to be replaced and unit
retuned.

10 December, 1943

0630(I) Broke a training shaft on SJ radar.

1000(I) Entered area. No sights and heavy seas for past four days.

1006(I) Submerged to routine torpedoes and torpedo tubes.

1727(I) Surfaced in heavy seas.

- 2 -
[HANDWRITTEN: 7]

— page 15 —
1930(I) SJ radar back in commission. Ensign F. V. BATTIN is
deserving of special credit for manufacturing a new train-
ing shaft on the lathe and making this important unit
operative.
[STAMP: 1 02184]

11 December, 1943

0929(I) Sighted a flight of small planes (unidentified as to
type) bearing 225°T and distant about 5 miles. Submerged
to 150 feet and at 0950(I) commenced periscope watch.
Surfaced at dark.

12 December, 1943

Cruising submerged in heavy seas taking a periscope
look every 15 minutes.

1040(I) Had doubtful sound contact of high speed screws.
Broached for thorough look with nothing in sight.

13 December, 1943

0040(I) Picked up Taiwan East Coast on radar at range 65,000
yards.

0600(I) Sighted Taiwan on port bow.

0655(I) Submerged conducting patrol 5 miles from and paralleling
beach from Karenko to Suo Wan during day. Visibility 15 miles,
100% overcast, and with heavy seas.

1830(I) Surfaced and headed to Northward to patrol area to East-
ward of Hoka Sho and as far South as Sancho Koha during night.

14 December, 1943

0655(I) Submerged and commenced periscope patrol along 60 fathom
curve East of Hoka Sho. Seas moderating, visibility fair,
100% overcast.

1914(I) Made radar contact. Closed the range until sighted contact.
It was a sampan. Decided to patrol near Hoka Sho and entrances
to Kirun Ko next day.

2216(I) Obtained fix using Hoka Sho light, soundings, and radar.

15 December, 1943

0650(I) Patrolling near 100 fathom curve covering approaches from
Eastward to Kirun Ko. Seas calm with a few whitecaps. Made
radar contact on ship bearing 070°T., range 21,700 yards.

0656(I) Sighted mast of a ship bearing 070°T. Made quick dive
and started approach.

- 3 -
[HANDWRITTEN: 8]

— page 16 —
0722(I) Sound picked up echo ranging on 17 Kc bearing 044° T.
0730(I) Sighted ship through periscope.
0750(I) Sighted a convoy of three ships with a tanker in the
center of two freighters and a destroyer escort ahead and astern.
0816(I) Fired four bow tubes at tanker.
0817(I) Started deep to avoid a destroyer bearing 300° relative,
angle on bow 5° starboard, range 800-1000 yards.
0819(I) Heard torpedo explosion.
0821(I) First depth charge.
0821-30(I) Second depth charge.
0823(I) Third depth charge.
0825-30(I) Fourth depth charge.
0826(?)(I) At deep submergence. Commenced evasion tactics, keeping
pinging destroyer astern. This destroyer pinged on us until
1355(I).
1432(I) Came to periscope depth. Nothing in sight.
1656(I) Heard a series of depth charges at a distance.
1657(I) Heard two series of depth charges at a distance.
1845(I) Surfaced and cleared area at standard speed. Decided to
patrol channels through Sakishima Gunto. Set course for new
position.
17 December, 1943.
0715(I) Made possible sound contact bearing 070°T. Nothing in
sight through periscope.
0740(I) The sound heard at 0715(I) came in again bearing 083°T.,
and sounded somewhat like a submarine. Nothing in sight.
This sound faded away and was not regained.
1827(I) Surfaced.
1831(I) Radar made contact bearing 160°T., distance 27,800 yards.
1835(I) Sighted smoke on same as radar bearing during evening
twilight. Commenced radar tracking. It soon became apparent
that it would be an end around as we were astern of a convoy.
- 4 -
[HANDWRITTEN: 9]

— page 17 —
Two engines on propulsion, two engines on charge.

1930(I) Radar picked up another group of ships ahead of the group
being tracked. Commenced tracking this group. Leading group
was zig zagging with courses of 180°T and 270°T as extremes,
at a speed of 12 knots. After group was closing leading group
at 15 knots.
1 02184

1940(I) Went to three engine speed.

1950(I) A third group of ships was picked up by radar. A brief
track indicated this group was closing from the Northwestward.
Continued tracking the leading ships.

1957(I) Went to four engine speed.

2025(I) Convoy sighted on bridge. There were several smoky Marus
and it was now easy to keep convoy in sight. Range had
closed to about 14,000 yards on nearest ships. All the ships
were now operating as one unit and cruising at 12 knots.
Signalling between ships by dimmed blinker lights was observed
from time to time.

2130(I) Continued tracking and gaining position ahead. The
relative size of the radar pips and bridge observations
indicated that the largest ships were in the center. These
ships had previously been making 15 knots.

2145(I) Went to battle stations. Secured the battery charge.

2205(I) In good position ahead. Turned toward for a surface
attack on course for a 90° port track.

2220(I) Targets were close enough now to see the whole formation.
The three groups were in column and the ships of each group
were in line of bearing and overlapping, and they obscured
about 090° of the horizon.

2225(I) Commenced firing bow tubes. Ships of the center group
started a simultaneous turn toward of about 90° during the
firing. Five bow tubes were fired when a turn away was
made to bring the stern tubes to bear. Conning Officer
thought at the time that all bow tubes had fired.

2226(I) Fired stern tubes at a large tanker and adjacent freighter
overlapping astern.

2227(I) Commenced a series of maneuvers at full speed to clear
area on surface. The PPI radar screen showed echoes at
saturation point bearing from 040° relative, clockwise to
290° relative, with a minimum range of 1200 yards. A series
of underwater explosions commenced that lasted for about

[HANDWRITTEN: 10]
- 5 -

— page 18 —
15-20 minutes duration. Destroyers started firing their guns,
I dont know why. No splashes were observed. Various ships
began to circle and some were blowing sirens and whistles.

2230(I) Observed a large transport go down bow first, tail in the
air and with her siren blowing, about 1500 yards abeam to port.
She was turning toward us as she sank. This was by far the
largest ship seen from the bridge.

2231(I) Observed a medium to large freighter submerge with about
a 15° down angle. This ship had been on the transports
port quarter and was a little abaft our port beam.

2232-3(I) Observed a medium sized freighter on our starboard quarter,
roll over to starboard, lay on her side for a moment and then
sink.

Observed a tanker astern settle in the water and go down by the
bow until the bow was awash. Tanker was presenting her star-
board beam to us. We thought she was sinking. A freighter
came alongside tankers starboard side. A small ship, probably
a trawler, went to the port side. A destroyer was astern
firing her guns. After about thirty minutes tanker was
being towed by the freighter.

2245(I) The moon came up, and although the sky was partially
overcast, the visibility had increased considerably. Attempted
to send contact report on 450 Kc. Air was jammed with Jap
transmissions on same frequency.

2305(I) Reload completed. Convoy had scattered to the Eastward
except for one group of four freighters and two escorts.
They were in a line of bearing, zig zagging radically every 6
minutes, and making 12 knots. The crippled tanker in tow
was on the same base course as this convoy but was rapidly
drawing aft. She was making about 2-3 knots on a towline.
Commenced tracking.

18 December, 1943

0149(I) In position ahead. Dove to radar depth and turned to
close track.

0210(I) Went to 55' periscope depth.

0229(I) Fired three bow tubes at freighter in center of convoy
and three bow tubes at overlapping freighter to the right
and ahead.

0230(I) Saw explosion and orange colored flame from one freighter.
Sound reported high speed screws close aboard. Started deep.
Four torpedo explosions were heard. Just before the periscope
went under saw one ship turning toward ASPRO.
- 6 -

[HANDWRITTEN: //]

— page 19 —
0232(I) Depth charging commenced, none close. These explosions
lasted for about one hour. No echo ranging was heard. Set
course to Northeastward to clear area and converge on tanker
damaged in earlier attack.
0233(I) After battery reported a ship passing overhead.
0540(I) Came to radar depth for search. Nothing in sight.
0600(I) Surfaced. Started a quick charge. Broadcast contact
report using both area frequency and 4235 Kc. Much Jap
interference.
0657(I) Submerged and continued search to northward and then to
eastward for tanker.
0955(I) Had momentary doubtful sound contact. Nothing in sight
at 50'.
1745(I) Heard long scale pinging bearing 310°T. Nothing in sight.
1846(I) Surfaced.
2100(I) Sent ASPRO serial one to Comsubpac, no receipt.

19 December, 1943
0641(I) Submerged.
0703(I) Heard light screws bearing 249°T. Nothing in sight and
screws faded out after a few minutes.

20 December, 1943
0329(I) Transmitted ASPRO serial two to Comsubpac.
2030(I) Set course to clear area for Midway, patrolling enroute
and advancing one hundred fifty miles per day to Longs 155 E.,
in accordance with Comsubpac serial 35 easy.

22 December, 1943
1942(I) Sighted a light bearing 073° T.
2017(I) Made radar contact on a ship, range 16,000 yards. Ship
was on course 195° T at 9 knots.
2147(I) Ship passed astern at range of 7000 yards. Ship was
identified as a small (about 2000 ton) hospital ship with
proper lights burning.

- 7 -
[HANDWRITTEN: 12]

— page 20 —
26 December, 1943
1005(J) Sighted small trawler (about 250-300 tons) from bridge.
         Submerged and closed for good observation.
1300(J) Celebrated Christmas dinner submerged.
1440(J) Surfaced. Trawler out of sight.

27 December, 1943
1920(J) Radar made contact on a ship bearing 119°T., range 16,600
         yards. Commenced tracking. Visibility was about 100 yards
         and it was raining very hard.
1950(J) Radar echoed on smaller pip astern of target. Assumed to
         be an escort.
2010(J) Closed to 700 yards range and could not see either ship.
2049(J) Fired four stern tubes at targets and cleared area.
2054(J) Heard five explosions at about 20 second intervals.
2130(J) Targets faded out on radar screen at 18,000 yards.
2145(J) Sent contact report to Comsubpac and on area frequency.

29 December, 1943
1455(J) Radar made plane contact distance 18 miles moving in.
1459(J) Submerged to avoid unidentified plane.
1629(J) Surfaced.

1 January, 1944
1210(L) Sighted PBY. Exchanged recognition signals.

2 January, 1944
0320(L) Crossed 180th meridian. Gained a day.

1 January, 1944
1000(Y) Sighted escort planes from Midway. Exchanged recognition
         signals.
1330(Y) Moored at Midway Island.

- 8 -

[HANDWRITTEN: 13]

— page 21 —
(C) WEATHER
        In the area sea conditions were generally 3 or 4 from North-
        east. The wind prevailed from the Northeast force 3 to 4.
        Skies were generally overcast and rainsqualls were encountered
        frequently. With the exception of the period 14 to 19
        December the seas were too high for good torpedo performance
        at depths of less than twelve feet.
[STAMP: 1 02184]

(D) TIDAL INFORMATION
        Accurate determination of currents were impossible due to
        the infrequency with which fixes could be obtained. The
        Japan Current and tidal drift off Hoka Sho agreed in general
        with pilots and information in other boats' patrol reports.

(E) NAVIGATIONAL AIDS
        Hoka Sho was the only navigational aid sighted. It showed
        normal characteristics at reduced intensity.

(F) SHIP CONTACTS (Separate page).

(G) AIRCRAFT CONTACTS (Separate page).

(H) ATTACK DATA (Separate page).

(I) MINES
        None

(J) ANTI-SUBMARINE MEASURES AND EVASIVE TACTICS
        The escorts during the first attack echo ranged in our
        vicinity for over five hours and passed us close aboard several
        times. We evaded by maneuvering to keep the destroyer astern
        and cruising silently at deep submergence. Of the depth charges
        dropped none were believed to have been closer than three
        hundred yards. We were not sighted during the second attack
        and evaded on the surface during the confusion. The enemy fired
        guns and dropped many depth charges but none of these measures
        was effective. Depth charges were dropped after the third
        attack but none were close. There was no echo ranging after
        this attack. The enemy was content to drop depth charges and
        clear the vicinity. Echo ranging was heard in the area
        during the day following this attack. No anti-submarine
        measures were taken in the fourth attack.

- 9 -
[HANDWRITTEN: 14]

— page 22 —
(K) MAJOR DEFECTS AND DAMAGE

1. The shear pin installed in the coupling between the bow
plane rigging motor and rigging gear sheared. Repaired in two
and one half hours.

2. There is a rubbing noise in the starboard propellor shaft.
Noise is very audible between 36 and 47 turns. The packing
may be turning with the shaft at low speeds. Water came in
above the gland instead of below and along the shaft.

3. Numerous sea valves and all valves on trim manifold leak.

4. Battery cell No. 74 forward is defective. Specific
gravity lags and voltage remains low. Sulphation is indicated.
Cell has been treated as outlined in Chapter 29 M.E.I.,
29-213(2). The cell gasses on open circuit and during discharge
and has an excessive sp. gr. drop on open circuit. There may
be local action present. A sample of cell electrolyte was
tested in November and found satisfactory.

5. The deck plating forward has buckled and sagged and was
caused by heavy seas and insufficient bracing. The after bow
buoyancy bulkhead is bellied out and moves forward and aft
at its center with the sea to the accompaniment of banging
noises. The strength members inside of the tank are torn
loose. It is necessary to run with the vents open.

6. Various silver soldered joints in the refrigeration system
leaked and were repaired on station.

(L) RADIO

On station in the Taiwan area 9090 Kcs was the most
reliable HAIKU frequency although Japanese interference was
constantly encountered. 4545 Kcs was usable between 0300 and
0600 LCT. Japanese interference was also encountered on
this frequency. 16.68 Kcs was signal strength one or two
at all times. 14,390 Kcs was a good standby frequency usually
at signal strength five.

To and from station the reliable frequencies were 9090 Kcs and
4525 Kcs. Low frequency (16.68 Kcs) is good after passing 142
degrees longitude, traveling east.

An important factor in reception was the ship's heading.
Placing the antennae parallel to the wave front produced a marked
increase in signal strength.

- 10 -

[HANDWRITTEN: 15]

— page 23 —
1 02184

(F) SHIP CONTACTS
No. | Time | Date | Lat. | Long. | Type | Initial Range | Est. Course and speed | How Contacted | Remarks
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
1. | 0830(K) | 12/2/43 | 28-05 N | 167-38 E | Sub. | 8 miles | 090 | Lookout | 1 SS surfaced. Appeared to be an EB boat. Submerged on sighting us
2. | 1840(K) | 12/4/43 | 27-46 N | 156-16 E | Sampan | 5 miles | Stopped | Lookout | 100 ton Jap fishing Sampan showing lights apparently engaged in taking in nets. First picked up lights then sighted one more Sampan in vicinity during attack.
3. | 1119(J) | 12/8/43 | 21-31 N | 129-10 E | Sampan | 6 miles | 270 Slow or stopped | Lookout | Sampan with 2 stick masts and deck house amidships (100 tons).
4. | 1347(J) | 12/8/43 | 21-34 N | 129-01 E | Patrol Boat | 6 miles | 110 High | Lookout | Patrol Boat
5. | 2335(J) | 12/8/43 | 21-05 N | 126-58 E | Sampan | 1.5 miles | 257 Slow or stopped | Radar | Sampan
6. | 0656(I) | 12/15/43 | 21-00 N | 125-34 E | 1 AO, 2 DD, 2 AK | 10.5 miles | 240 12 kts. | Radar Sight | One AO, two AK and 2 DD (2 stack) escorts Radar - Sight.
7. | 1835(I) | 12/15/43 | 21-33 N | 125-31 E | AK's, DD Trawler, AO AP | 14 miles | 250 12 kts | Radar | About 15 ships with DD, trawler escorts Some AO, large and medium AK, AP.

[HANDWRITTEN: 16]
11 -

— page 24 —
(F) SHIP CONTACTS (CON'T)

No. | Time | Date | Lat. | Long | Type | Initial Range | Est. Course and speed | How Contacted | Remarks
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
8 | 1942(I) | 12/22/43 | 23-51 N | 133-50 E | Hospital Ship | 6 miles | 220 | Sight |
| | | | | | | | 10 kts. | |
9 | 1005(J) | 12/26/43 | 23-35 N | 145-15 E | Trawler | 7 miles | 330° | Sight |
| | | | | | | | 8 kts. | |
10 | 1920(J) | 12/27/43 | 26-16 N | 148-14 E | Unknown | 8.5 miles | 300° | Radar | 2 radar contacts.
| | | | | | | | 9 kts. | |

(G) AIR CRAFT CONTACTS

No. | Time | Date | Lat. | Long | Type | Initial Range | Est. Course and speed | How Contacted | Remarks
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
1. | 0929 (I) | 12/11/43 | 23-20 N | 126-30 E | Unknown | 5-7 miles | Unknown | Sight | Probably 12 (4
| formations of 3(?)).
| [HANDWRITTEN: - 12 -]
2. | 1455(J) | 12/29/43 | 28-15 N | 158-29 E | Unknown | 18 miles | 180°T | Radar | On surface. Picked
| up by SD radar 18
| miles. Closed to 14
| miles when we
| submerged. Last
| contact 13 miles
| going down.
3. | 1210(L) | 1/1/44 | 28-10 N | 175-29 E | PBM | 8 miles | Unknown | Lookout |

[HANDWRITTEN: 17]

— page 25 —
[STAMP: 1 02184]

(H) ATTACK DATA
U.S.S. ASPRO                               TORPEDO ATTACK NO. 1             PATROL NO. 1
TIME 0816(I)                              DATE 15 December, 1943  LAT 25-67 N  LONG 122-33 E

                                          TARGET DATA - DAMAGE INFLICTED

Description: Sighted on surface by radar and lookouts almost
             simultaneously at dawn, a convoy of one loaded
             tanker and two freighters with two destroyer escorts.
             Ships were in line of bearing with tanker in center
             and escorts patrolling ahead and astern.

Ships similar to:
             One (1) - AO San Pedro Maru Class (7300 tons)
             Two (2) - AK's Unidentified (4-5000 tons each)
             Two (2) - DD's Kamikaze class.

Ships sunk: None

Ship damaged or probably sunk: One (1) - Unknown (probably tanker).

Damage Determined by: One torpex explosion was heard and felt in
             boat. Although tanker was the target it is not
             known which target was hit. Sound heard nothing
             except that torpedoes at the start of their run
             seemed to be running to pass ahead of target.
             It is believed that either the leading Maru or the
             tanker was hit.

Target Draft 28'         Course 260°         Speed 12         Range 1675 yards.

                                                OWN SHIP DATA

Speed 3 kts.             Course 168°         Depth 60'        Angle 0

                                          FIRE CONTROL AND TORPEDO DATA

Type Attack: Day periscope attack with torpedoes set to run at 8'.
             It was planned to fire two bow torpedoes at the lead-
             ing freighter and four at the tanker and swing to
             stern shots. Came in for a 90° port track. When
             range was 2800 yards, targets zigged toward giving a
             0-5° port angle on bow. Made a turn inward to
             swing stern into the bearing and bring stern tubes
             to bear. During the turn targets zigged away again
             and presented a starboard track. Fired four bow
             tubes with a large track. The setup was poor,
             but I felt that it would be my only chance at this
             convoy, as it was entering the port of Hirum Ko.

                                                - 13 -

[HANDWRITTEN: 18]

— page 26 —
[HANDWRITTEN: 20]
[HANDWRITTEN: 23]

(H) ATTACK DATA (CON'T)
| | No. 1 | No. 2 | No. 3 | No. 4 |
|---|---|---|---|---|
| Tubes fired | 1 | 1 | 1 | 1 |
| Track angle | 126 S | 131 S | 130 S | 134 S |
| Gyro angle | 37 R | 42 R | 42 R | 46 R |
| Depth set | 8' | 8' | 8' | 8' |
| Power | High | High | High | High |
| Hit or Miss | Hit | Miss | Miss | Miss |
| Erratic | No | No | No | No |
| Mark torpedo | XIV-3A | XIV-3A | XIV-3A | XIV-3A |
| Serial No. | 39839 | 39884 | 25904 | 25993 |
| Mark exploder | VI-1A | VI-1A | VI-1A | VI-1A |
| Serial No. | 6542 | 1627 | 7737 | 12076 |
| Mark warhead | XVI | XVI | XVI | XVI |
| Serial No. | 301 | 11057 | 10338 | 1157 |
| Firing interval | 0 | 15 | 9 | 11 |
| Type spread | 0 | 2 R | 2 L | 0 |
| Sea Conditions | Calm - Whitecaps | | | |
| Overhaul activity | USS BUSHNELL | S/M Base, Pearl | | |

U.S.S. ASPRO
TIME 2225(I) | [HANDWRITTEN: 20] [HANDWRITTEN: 5 (arrow down)]
| TORPEDO ATTACK NO. 2
DATE 17 December, 1943 | LAT. 73-59 N | LONG. 124-42 E | [HANDWRITTEN: PATROL NO. 1]

TARGET DATA - DAMAGE INFLICTED

Description: A convoy of fifteen ships were cruising in three
groups in column, each group consisting of five
ships in line of bearing. Two escorts, trawlers
and destroyers, were with each group, and they
patrolled ahead, astern, and on the wings of the
convoy. Sea was calm, sky partially overcast, and
it was quite dark.

Ships fired upon similar to:

BOW TUBES
(1) One (1) - AP - Identified as either KAMAKURA MARU (17526 tons),
or HEIAN MARU (11,620 tons), shown on pages 25 and 68 ONI 208 J.
(2) One (1) - AK - Unidentified. (7000 tons)

STERN TUBES
(3) One (1) - AO - TOHO MARU class, (10050 tons), page 264, ONI J
(4) One (1) - AK - Unidentified (7000 tons).

- 14 -
[HANDWRITTEN: 19]

— page 27 —
Ships Sunk: One (1) AP Positive identification uncertain (see above).
One (1) AK Unidentified, (7000 tons).
One (1) AK Unidentified, (7000 tons).
Ships Damaged or Probably Sunk: One (1) AO - TOHO MARU class (10050 tons). [HANDWRITTEN: 1 02184]
Damage Determined by: Captain, officers, and lookouts on the bridge
observed.

(1) AP settle down by the bow, turn toward ASPRO, and
sink close aboard (about 1500 yards) on port beam about
five minutes after firing.
(2) AK sink about six (6) minutes after firing. She
had been on AP's port quarter.
(3) AK astern of AO rolled over and sank about 6-7
minutes after firing. Bearing was 170° relative.
Captain was conning forward and did not observe this.
(4) AO settled in water about 8 feet overall, was bow
down until bow was awash. A Maru came alongside and
took tanker in tow. A trawler also was alongside
for possibly thirty minutes. Tanker smoked
a great deal but no flames were seen.

Target Draft: AP (est) 25' Course Bow tubes 270°T - Speed Bow tubes 12 kts.
AK (est) 20' " stern " 180°T - " stern " 10 "
AK (est) 20' Range - bow tubes - 2400 yards
AO(light)11' " stern " 2500 yards

O'N SHIP DATA

SPEED | COURSE | DEPTH | ANGLE
Bow tubes 8.0 knots | Bow tubes 010°T | Surface | 0
Stern tubes 12.0 kts.(App) | Stern tubes 250°T | |

FIRE CONTROL AND TORPEDO DATA

Type Attack: A night surface attack using radar ranges and T.B.T.
bearings. Attack was made on the center group of
ships. These ships were the largest and they tracked
at 15 knots while they were closing the leading group.
At time of firing ships overlapped and obscured about
90 degrees of the horizon. The torpedoes were set
to run at 6 feet. The targets zigged toward while
firing the bow tubes. Only five bow tubes were fired as
the turn away was commenced too early. ASPRO retired
on surface for reload.

- 15 -
[HANDWRITTEN: 20]

— page 29 —
1 02184

(H) ATTACK DATA (CON'T)
plus escorts had reformed and were cruising in a
line of bearing, and zig zagging as much as 90°
every 6 minutes. A fairly bright moon had risen,
visibility was good, and seas were calm.

Ships fired Upon Similar to:
One (1) AK- Unidentified (7000 tons)
One (1) AK - Unidentified (7000 tons)

Ships Sunk: Unknown.

Ships Damaged or Probably Sunk:
One (1) AK - Unidentified (7000 tons)
One (1) AK - Unidentified (7000 tons)

Damage Determined by:

Saw through periscope one large orange colored
burst of fire just prior to periscope going
under. Sound tracked three torpedoes to target
and heard torpedo and ship screws merge together,
and followed by torpedo explosions. These screws
were heard no more. JP-1 sound gear tracked
second spread of three torpedoes to target and
heard torpedo explosions. These screws stopped
but were soon heard again turning over slowly
and they sounded like they might be laboring.
These screws were heard clearly for about an hour
and then heard no more. Four torpedo explosions
in all were heard. Upon surfacing there was a
smell of fuel oil and fuel oil could be tasted in
the water remaining on the bridge.

Target Draft 20'(est.) Course 200°T Speed 11.5 knots Range 2470 yds.

OWN SHIP DATA

Speed 4 kts. Course 095° Depth 55' Angle 0° to 1° D.

FIRE CONTROL AND TORPEDO DATA

Type Attack: Combined surface radar, submerged radar, and night
periscope attack in fairly bright moonlight.
The torpedoes were set to run at 6 feet. Three bow
tubes were fired at one freighter and then shifted
to fire three at freighter ahead.

- 17 -

[HANDWRITTEN: 22]

— page 32 —
(M) RADAR

SJ - The maximum range obtained on the large convoy was
32000 yards.

The maximum ranges obtained were estimated at about 90,000
yards on the island of Formosa.

Interference was encountered off Formosa the night after
the first attack but radar personnel was unable to
identify the cause.

The new PPI scope was invaluable during the second and third
attacks and was a Godsend in getting clear of the many ships
after the second attack.

MATERIEL FAILURES - SJ

7 December, 1943: Time delay relay switch burned out in main
control unit.

9 December, 1943: The vertical shaft from the training motor to
upper gear box broke. A new shaft was manufactured and
installed in 12 hours.

17 December, 1943: The lobe switching motor burned out.

19 December, 1943: Could not get radar to focus properly.
Replaced cathode ray tube and put apparatus back in commission
in 8 hours.

SD- The radar was used intermittently when in operation. Had
plane contact at 18 miles when North of Marcus Island and
returning to Midway.

Had radar interference centering in the Bonins which lasted
for about an 800 mile run as we approached and passed through
Westward.

(N) SOUND

In the first attack echo ranging was detected on 17 Kcs at
approximately nine thousand yards. The screws of the leading
ship in the convoy, a destroyer, were detected at five thousand
six hundred yards. The screws of the other vessels were heard
soon thereafter as they approached this range. After the attack
the trailing destroyer broke off and came in for her depth
charge attack, approaching to within an estimated three hundred
to five hundred yards, slowed down, and echo ranged on a four
second scale. The vessel passed both beams three times at

- 20 -

[HANDWRITTEN: 25]

— page 33 —
1 02184
this range, definitely ranging directly on our sides. As he
did not make his depth charge run at any of these times it
is apparent that he was not getting contact. The depth at this
time was four hundred fifty feet. The bathythermograph
indicated several thermal gradients as follows:

DEPTH(Feet)           TEMPERATURE(F)
20-200                 77
200-225                76
225-300                69
300-360                69
360-400                66
400-420                69
420-450                74

From these values it seems that a variation of only ten
degrees temperature will refract sound waves sufficiently at
the estimated three hundred to five hundred yards to prevent
a successful sound attack.

There was no echo ranging during the third attack. The JP
first picked up screws at approximately nine thousand yards.
The QB and JK sound gear were unable to hear the screws
until the range had closed to thirty nine hundred yards.
Sound conditions in the area were good.

(0) DENSITY LAYERS

The following density layers were observed:

DATE                 POSITION         TIME(-9)      DEPTH      TEMPERATURE
15 December, 1943    LAT 25-05 N      0840(I)       255-300    75-69
                     LONG 122-33 E
15 December, 1943    Same             0900(I)       360-390    69-66
15 December, 1943    Same             1300-1700(I)  390-450    66-75

During the dive on 15 December temperature gradients
changed radically during the afternoon, ending up with an
isothermal layer to 400 feet at 1700.

On 18 December, 1943, at about 0220(I) an isothermal layer
was encountered from keel depth at the surface to 400 feet
in depth, necessitating pumping out of 11,500 lbs. of ballast
to retain a diving trim. Position LAT 23-32 N, LONG 124-16 E.
Temperature 78°.

- 21 -

[HANDWRITTEN: 26]

— page 34 —
(P) HEALTH, FOOD AND HABITABILITY
Health in general was excellent with only a few colds,
and the usual minor injuries.

Food was well prepared, with plenty of variety.

Habitability was excellent.

(Q) PERSONNEL
An inexperienced crew had developed into a fast thinking
well coordinated team by the time of departure for the area.
The morale has been excellent at all times. Lieutenant
J. G. ANDREWS, U.S.N., the Executive Officer, merits a "well
done" for his painstaking efforts in organizing and training.
Lieutenant L. H. BUTT, U.S.N.R., is to be commended for his
perseverance and study of the T.D.C.

(R) MILES STEAMED - FUEL USED

| | Miles | Fuel(gallons) |
| :| :---- | :|
| Pearl to Midway | 1340 | 14,640 |
| Midway to Area | 2815 | 20,826 |
| In Area | 1564 | 13,524 |
| Area to Midway | 2824 | 27,746 |

(S) DURATION

| | |
| :| :---- |
| Days enroute to area | 15 |
| Days in area | 12 |
| Days returning | 12 |
| Days submerged | 11 |

The patrol was terminated by order of Comsubpac.

(T) FACTORS OF ENDURANCE REMAINING

| | | | |
| :| :------ | :| :-- |
| Fuel | 31,950 | Provisions | 35 |
| Torpedoes | 1 | Personnel | 25 |

(U) REMARKS
The importance of the new PPI scope with high power transmitter
can not be fully appreciated until it has been used in an engage-
ment with a large convoy. It enables the conning officer to get
a complete picture of the formation, and it helps to eliminate
the worry of "where are the escorts now". The little pips
stand out and their significance are appreciated as they change
bearing relative to the larger pips.

- 22 -

[HANDWRITTEN: 27]

— page 35 —
(U) REMARKS (CON'T)

The early development and installation of a good night
periscope with a radar attached is extremely desirable.

All compartments are very comfortable except for the
maneuvering room. It is recommended that the maneuvering
room head be removed and an air conditioning unit be installed
in the space made available. This unit would serve both the
maneuvering room and after torpedo room.

1 02184

- 23 -
[HANDWRITTEN: 28]

— page 36 —
A16-3                                COMMANDER SUBMARINE FORCE, PACIFIC FLEET, 1 02184
Serial 03                                SUBORDINATE COMMAND, NAVY NO. 1504.

C-O-N-F-I-D-E-N-T-I-A-L                     Care of Fleet Post Office,
                                            San Francisco, California,
FIRST ENDORSEMENT to                        2 January 1944.
USS ASPRO Conf. Ltr.
SS309/A16-3 Serial 01-44
dated 1 January 1944.

From:             The Commander Submarine Force, Pacific Fleet,
                  Subordinate Command.
To :              The Commander-in-Chief, United States Fleet.
Via :             (1) Commander Submarine Force, Pacific Fleet.
                  (2) Commander-in-Chief, United States Pacific
                      Fleet.

Subject:          U.S.S. ASPRO, Report of War Patrol Number One.

                  1.
                  ASPRO first war patrol extended over a period of
thirty-eight days, eleven days of which were spent in patrol area.
Patrol was terminated by expenditure of torpedoes.

                  2.
                  Three contacts were made giving ASPRO opportunity
for four torpedo attacks, two attacks being made on one convoy of
15 ships. In addition, gunfire was used in a night attack on a
lighted sampan. When the second salvo hit, sampan extinguished
lights and gun crew were unable to find target so attack was
abandoned.

                  (a) A radically zig-zagging convoy of 2 AKs and 1 AO escort-
                  ed by 2 DDs was attacked with four torpedoes on ASPRO
                  first attack resulting in one definite torpedo explosion
                  after a 3 minute run but immediate depth charge attack
                  prevented observation of damage. This explosion may
                  have been a hit on the leading ship of this convoy by
                  any one of the four torpedoes fired if enemy ran away
                  in attempt to avoid.

                  (b) Soon after surfacing night of 17 December, ASPRO made
                  contact with a large heavily escorted convoy of 15 ships.
                  After tracking them for 2½ hours two night surface attacks
                  were made. On the first attack using bow and stern tubes
                  the largest ship in convoy, a transport, was sunk, as well
                  as 2 large freighters and a damaged tanker with bow awash
                  was last seen being towed. During retirement for reload,
                  destroyer gunfire was observed but no splashes were seen.

                                            -1-
[HANDWRITTEN: 3]

— page 37 —
A16-3
Serial 03
C-O-N-F-I-D-E-N-T-I-A-L
Subject: U.S.S. ASPRO, Report of War Patrol Number One.

COMMANDER SUBMARINE FORCE, PACIFIC FLEET,
SUBORDINATE COMMAND, NAVY NO. 1504.

Care of Fleet Post Office,
San Francisco, California,
2 January 1943.

ASPRO then came in for second attack using 3 bow tubes
against one freighter and 3 against another in moonlight
at periscope depth. Explosion was seen in one target
when proximity of high speed screws and subsequent depth
charging prevented further observation. Four explosions
were heard and it is highly probable that one freighter
was sunk from 3 hits and one damaged. Attempt was made to
relocate towed tanker without success.

(c) Five days later a night surface radar attack was made
using remaining torpedoes aft on 2 unseen targets, prob-
ably one ship with one escort, at close range in a heavy
rain. Misses were probably caused by casualty to radar
resulting in incorrect firing bearing.

3. ASPRO returned in good material condition. Refit
will be accomplished in normal period. The Commanding Officer,
officers and crew are congratulated on this aggressive first patrol.

4. ASPRO recommendation that an air conditioning unit be
installed in space now occupied by maneuvering room head has merit and
is concurred in.

J. A. CONNOLLY.

Copy to:
CO ASPRO.

[HANDWRITTEN: 4]

— page 38 —
[STAMP: Reg. No. 25477]
[STAMP: ch 1 02184]
[STAMP: S. No. ]

FF12-10/A16-3(8)/(16)
SUBMARINE FORCE, PACIFIC FLEET
Serial 067
Care of Fleet Post Office,
San Francisco, California,
9 January 1944.
CONFIDENTIAL
NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
ENTERING PATROL AREA.
SECOND ENDORSEMENT to
ASPRO Report of First
War Patrol.

COMSUBSPAC PATROL REPORT NO. 344
U.S.S. ASPRO - FIRST WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet.
To : The Commander-in-Chief, United States Fleet.
Via : The Commander-in-Chief, U. S. Pacific Fleet.

Subject: U.S.S. ASPRO (SS309) - Report of First War Patrol.
(24 November, 1943, to 1 January, 1944).

1. The first War Patrol of the ASPRO was conducted in the East China
Sea around the Island of FORMOSA. The patrol was aggressive and successful.

2. The highlights of this patrol were the well executed attacks made
on a convoy of fifteen ships the night of 17-18 December. Making excellent use
of the PPI, the ASPRO obtained a favorable firing position on the largest ship of
the convoy, and within two minutes, nine torpedoes were fired at four ships, sink-
ing three and badly damaging the fourth. The ASPRO then conducted a reload and
five hours later made a second attack, hit two more freighters, probably sinking
at least one of them. These well conducted attacks were aggressively made.

3. The gun attack made on the sampan the night of December 8 indicates
the importance of maintaining strategic fire power advent of such type targets.
Complete destruction of these targets is absolutely necessary before attempting
to close them within range of any type gun that they may carry. Destruction of
sampans by U.S. submarines is of course a known fact to the Japanese. Therefore,
it is safe to assume that they will attempt to employ any trick possible that
might result in severe damage or ultimate destruction to one of our submarines.

4. This patrol is considered successful for Combat Insignia award.

5. The Commander Submarine Force, Pacific Fleet, congratulates the
Commanding Officer, officers, and crew for this aggressive and successful first
war patrol, and particularly for the destruction accomplished on the Japanese
convoy. The ASPRO is credited with having inflicted the following damage upon
the enemy:

S U N K
1 - Transport (HELAN MARU class) - 11,620 tons
1 - Freighter (unidentified) - 7,000 tons
1 - Freighter (unidentified) - 7,000 tons
Total - 25,620 tons

- 1 -

— page 41 —
[HANDWRITTEN: 1st COPY]

U.S.S. ASPRO (SS309)
Care of Fleet Post Office,
San Francisco, California,

SS309/A16-3
Serial (07)
[STAMP: DECLASSIFIED]

28 March, 1944.

From: The Commanding Officer.
To : The Commander-in-Chief, United States Fleet.
Via : (1) The Commander Submarine Division 201.
(2) The Commander Submarine Squadron 20.
(3) The Commander Submarine Force, Pacific Fleet.
(4) The Commander-in-Chief, U.S. Pacific Fleet.

Subject: U.S.S. ASPRO (SS309), Report of War Patrol Number Two.

Enclosure: (A) Subject Report.
(B) Track Chart (Comsubpac).

1. Enclosures (A) and (B), covering the second war patrol of
this ship conducted in the waters north of TRUK, during the period from
3 February, 1944 to 28 March, 1944, is forwarded herewith.

[SIGNATURE: W. A. Stevenson]
W. A. STEVENSON.

DECLASSIFIED-ART. 0445, OPNAVINST 5510.1C
BY [HANDWRITTEN: OP-09B9C] DATE [HANDWRITTEN: 5/23/72]

[HANDWRITTEN: 41204]

— page 42 —
CONFIDENTIAL

(A) PROLOGUE

Arrived MIDWAY from first war patrol on 1 January, 1944 for refit. Refit
completed 15 January, 1944. Lieutenant Commander T.A. STEVENSON, USN., relieved
Commander H.C. STEVENSON, USN., of command on 15 January, 1944. January 18
departed MIDWAY enroute PEARL HARBOR for training period. 22 January arrived
PEARL HARBOR. Conducted training from 24 January to 31 January. 1-2 February
fueled and provisioned ship.

(B) NARRATIVE

**3-7 February, 1944**

At 1300(VW) 3 February departed PEARL HARBOR for MIDWAY with PC580 as escort.
At 1550(VW) made trim dive. At 1935(VW) released escort and proceeded indepen-
dently. Conducted training enroute. Contacted air escort at 0700(Y) 7 February
and moored alongside U.S.S. ANGLER at MIDWAY at 0905(Y) 7 February. Took on
fuel, lub oil, and stores at MIDWAY, and at 1405(Y) departed for patrol area
under air coverage.

**7-13 February, 1944**

Enroute area. Conducted daily training dives, emergency drills, and
battle problems.
Unless otherwise noted in narrative all times are zone (-10).

**14 February, 1944**

1051 Made training dive.

1129 Started to surface after search with SD when plane (Betty) was sighted
dead ahead distant 6-7 miles, closing on a slightly divergent course.
Ordered 200 feet. Negative was flooded, secured main ballast tank blow,
bow planes rigged out. Plane sighted us and altered course to head for
us. We were hanging at 30 feet when it was realized vents had not been
opened. Plane should have been over us when we passed 50 feet. Since
we were 500 miles from any Jap base it is quite possible he was loaded
with fuel and carried no bombs.

1237 Surfaced.

1247 Plane sighted. Dove. Do not believe we were sighted.

1259 Surfaced.

1333 Sighted same plane distant about 6 miles on parallel course. Dove.

1423 Surfaced.

**15 February, 1944**

0710 Entered area.

1002 Submerged to 200 feet to routine torpedoes.

1106 Sound contact. Secured from routining torpedoes and started to
plane up to periscope depth.

- 1 -
ENCLOSURE (A)

— page 43 —
1118 Periscope depth. Observed tops of what appeared to be sampan,
     astern.

1121 Identified ship as large Jap submarine, large structure aft of
     conning tower, possibly a midget submarine, numerals 443 and Jap flag
     painted on conning tower. Range was about 5000 yards with a large
     starboard angle. Turn count indicated a speed of about 17 knots.
     Commenced approach.

1142 Abandoned hope of making a submerged approach. Sub was opening
     range rapidly and zig zagging at high speed.

1207 Surfaced. Sub could just be seen through the periscope. No
     radar contact. Started an end around at flank speed on four engines,
     just keeping sub in sight through the periscope.

1545 Sub started to smoke badly. It is believed he stopped his
     engines in preparation to dive.

1555 Lost sight of sub. At the time he was at the extreme range
     of visibility through the periscope. A zig either took him out of
     visibility range or he made a dive. His base course had been
     determined to be about 155 T, this was the course for TRUK.

1700 Submarine again sighted through high periscope.

1845 Lost target through periscope due to darkness. Started to close
     to radar range.

1855 Picked up target on radar at 18,000 yards. It was necessary to
     close to 10,000 yards before reliable bearings could be obtained.

2012 Had gained position ahead of target.

2154 Determined zig plan, started to close. It was a dark night.

2223 Fired four torpedoes from the bow tubes at a range of 2100
     yards using radar ranges and bearings.

2224-35 Saw and heard first explosion followed by second. Two large
     orange balls of fire were seen and in the dim glow the bow was seen
     to rise as the submarine sank by the stern. The other two torpedoes
     could have hit but it was impossible to determine this from the
     conflagration caused by the two definite hits. Radar reported target
     disappeared from screen. Heavy black smoke covered the area where
     the submarine sank. For the next several minutes numerous explosions
     were heard.

2227 Violent explosion.

2235 Enroute to patrol station for operation in connection with the
     air raid of our surface Task force on TRUK.

                                  - 2 -
                                                          ENCLOSURE (A)

— page 44 —
16 February, 1944
1750 Distant depth charging.
1824 Surfaced. Radar interference experienced throughout the night.
     Our own subs were in the area.

17 February, 1944
0140 Radar contact, 40,000 yards. Continuous radar interference
     centered on this bearing had been observed for some time. Started to
     close range.

0212 Range closed to 28,000 yards, three or more pips were visible on
     the PPI screen. One contact was approximately 6000 yards closer than
     the main body. Came to course to converge about 30 degrees and went
     ahead flank speed on four engines to gain position ahead. Convoy
     was headed for TRUK, speed 7 knots.

0240 Heard depth charges through the hull. The target 6000 yards
     closer than the main body was thought at the time to have been the
     BURRFISH or TANG. This contact had pulled ahead to 30 degrees on the
     starboard bow, range 15,500 yards. Continued tracking convoy.

0250 The closest contact was now dead ahead and the range had closed
     to 9,500 yards. This contact is the center of the strongest radar
     interference. It was now apparent that we had been detected by a
     destroyer equipped with radar. Changed course to the right in an
     attempt to shake the escort and close in on the convoy more rapidly.

0255 Sighted destroyer forward of port beam, small angle on the bow,
     range 7,800 yards and closing. This was the contact that had been
     closing us and was radar equipped. He was signalling to another
     escort closer to the convoy. Turned away from closest destroyer
     but range started to decrease on escort that had previously been
     escorting close to convoy.

0300 Sighted the three ships of the convoy. The largest appeared
     to be a large tanker. We were still making flank speed on four engines.
     Decided to attempt to gain attack position on other side of convoy.

     Only the one destroyer seemed to be equipped with radar. He
     would signal the other destroyer from time to time. At one time
     closed to 9500 yards on the non radar destroyer but we apparently
     were not sighted.

0318 Radar destroyer who just an instant before was 6100 yards
     with a large starboard angle on our starboard quarter, suddenly
     bent on all burners and was closing us at a zero angle.
     Made quick dive. Ordered deep and rigged for depth
     charge. The range when we dove was 3600 yards.

0322 First pattern of five charges. Not nearly as close as expected.

- 3 -
ENCLOSURE (A)

— page 45 —
All appeared astern.
Destroyer crossed overhead and then commenced echo ranging.
Only one destroyer could be heard.

0325 Found an eight degree temperature gradient at 425 feet.
0335-0350 Seven depth charges, none very close. It is believed he
never made contact with his echo ranging.
0502 Pinging seemed more distant. Started to come up.
0514 Depth charge when passing 150 feet, not close. Started
deep.
0530 Started up again.
0534 Depth charge, not close.
0535 When passing 125 feet sound reported fast screw on our
port quarter. Ordered deep submergence. It is now believed
this was a false contact. The pinging still seemed quite dis-
tant.
0618 At periscope depth. All clear. Pinging could still be
heard bearing 130 degrees relative.

We should have been approximately 25 miles from our
patrol station that we had been directed to reach by daylight.
0745 Sighted plane "Dave" or "Pete" bearing 130 degrees rela-
tive, distant about seven miles. Heard distant depth charging
throughout the day.

1832 Surfaced.
1943 According to our fix we had experienced a westerly set and
were 23 miles from our patrol station. Went ahead two engine
speed.
2200 Arrived at patrol position.
2254 Radar contact 22,000 yards. Commenced tracking.
2309 The approximate course was determined as 130 T. Decided
to gain position ahead by remaining outside 23,000 yards to
avoid being detected by possible radar equipped destroyer.
We had information our own surface forces might be en-
countered.

18 February, 1944
0027 Gained position ahead of contact, range 24,000 yards.
The three to four contacts made small pips on the screen at
this range. Accurate bearings were impossible which made our
tracking problem difficult.

- 4 -

— page 46 —
The decision was made to attempt to track at this extreme
range for a while longer before closing to more favorable ran-
ges. The targets could have been destroyers - a larger target
should have given a better pip.

0148 Determined target group had reversed their base course.
     Reversed course and went ahead flank speed on four engines.

0215 PPI sweep indicated target dead ahead range 11,500 yards
     and closing. Reversed course to put contact astern.

0235 We seemed to have had a slight speed advantage. However,
     the range remained about constant around 11,000 yards, due
     to our efforts to work off the targets track. The target
     seemed able to detect these course changes and would continue
     to head for us.
     When the range had opened to 12,500 yards we were able to
     work around slowly to the left by maintaining the range greater
     than 12,000 yards.

0325 Lost contact with the target at a range of 15,000 yards.
     This was probably a patrol craft. Radar interference had been
     encountered throughout the night.
     Attempted to regain contact with the original group. Most
     probable intercept course headed us back toward our patrol sta-
     tion.

19-20 February, 1944
     Conducted submerged periscope patrol during daylight and
     patrolled five mile square on surface at night. (Lat. 8°-00N,
     Long. 150°-00E)

21 February, 1944
0145 Departed special patrol station to resume normal patrol.
1100 Sighted small sail sampan. Avoided.

22 February 1944
0600 Dove.
0730 Surfaced. Plane contacts on SD throughout the morning,
     18-23 miles.
1216 Dove. Plane contact on SD closed to 12 miles.
1940 Sent ASPRO serial one.

23 February 1944
0555 Dove
0615 Surfaced. Enroute to position 20 miles northeast of
     NAMONUITO to render lifeguard services today.

45

— page 47 —
0800 Entered area 15 N.
1120 Arrived on station. Plane contacts throughout morning on SD,
18-23 miles.

24 February, 1944

0558 Dove.
0710 Surfaced. Decided to patrol on surface to be available for
lifeguard services.
0847 Sighted plane, possibly a Liberator. Dove.
0859 Surfaced.
1026 Contact on SD at 16 miles. Radar interference on SD.
1110 Contact on SD at 6 miles. Dove. Plane was not sighted.
1345 Surfaced.
1605 Sighted sampan or patrol craft through the high periscope. Avoided

26 February, 1944

0855 Sighted plane through periscope.
0959 Sighted masts of ship close to reef, NORTH PASS. Commenced
approach.
1030 Determined contact was patrol vessel conducting listening
patrol on east and west courses, speed 6 knots.
1157 Target identified as small net tender. Broke off approach.
1915 Observed search lights on TRUK! This search light display was
visible every night about this same time up to a range of approximately
50 miles from TRUK.

29 February, 1944

0945 Sighted unidentified plane through the periscope.

2 March, 1944

0130 Radar contact, range 28,000 yards bearing 345 T. Commenced
tracking. This contact later proved to be one of the small islands
of MURILO atoll. The pip did not have the characteristics of land
and two experienced operators were fooled. Radar interference was
noted throughout the tracking. This interference indicates presence
of a radar station in the HALL Islands. Finally managed to get the
contact slowed to zero speed after a period of tracking. Secured
tracking after our mistake was realized.
- 6 -

— page 48 —
1130 Made passage between NOMWIN and MURILO Atolls. Nothing could
     be seen on these islands.

3 March, 1944

1200 Sound picked up pinging bearing 210 degrees relative.

1240 Sighted small patrol boat, later identified as PC boat. Tracked
     target on course 010 T., speed 12 kno's.

1248 Target sent two long pings with the projector trained right on
     us, then the pinging stopped all together. Continued to evade by
     running silent at periscope depth and keeping him astern.

1330 PC boat resumed pinging.

1338 Lost contact by periscope.

1406 Last contact of pinging by sound.

1510 Sighted plane through the periscope.

1752 Sighted ship bearing 299 T distant approximately 10 miles,
     large port angle. Came to normal approach course and started
     approach.

1818 Ship was a large passenger-freighter type and was pretty well
     identified as the HEIAN MARU.

1825 Commenced tracking at radar depth, range 17,500 yards.

1850 Surfaced. Commenced tracking at two engine speed. Radar inter-
     ference was noted, there were no other contacts.

1935 Secured charge on one engine. Went ahead flank on three engines.

2043 Went ahead flank speed on four engines. Continued charge on
     auxiliary. There was a bright moon and several times in gaining
     position ahead the target could be seen at a range of 17,000 yards.
     The range was never decreased below 17,000 yards.

2337 Had gained position ahead. Slowed and started approach. The
     zig plan had been determined; the plan ran for one hour with course
     changes every five minutes, speed 14 knots. The last hour of track-
     ing indicated an increase of speed to 16 knots.

     Visibility had decreased considerably. The moon was low, and
     the sky about 70% overcast. Decided to make a surface approach from
     the dark side of the horizon.

4 March, 1944

0110 Radar contact, range 10,400 yards, ahead on the far side of the
     target.
     It was now quite dark. The moon was about to set and was hidden
     by clouds. TBT bearings on the target could be given when the range

- 7 -

— page 49 —
was approximately 6000 yards.

0122        Fired six bow tubes with an average torpedo run of 3350 yards,
            one degree spread between torpedoes. The target was on a forty-
            five degree zig away in a minute and a half when firing commenced.
            The first three torpedoes were fired with the target on his first
            course and the last three with the target twenty degrees from his
            new course.

0125        Violent explosion which actually shook the boat. The range to
            the target was 4500 yards. Nothing was seen on the target to
            indicate a torpedo hit. However, a hit is claimed for the fifth
            torpedo fired (torpedo run of 2 minutes 10 seconds).

            The target turned on a light and flips for a few seconds, slowed
            and started to circle. The escort started to close the target.
            Lost I.C. power following the torpedo explosion.

0127        First of five explosions - end of run torpedo explosions.
            These end of run explosions, an analysis indicates, must have been
            near the position of the escort. This might account for the escort's
            failure to render any further assistance to the target.

0133        Started reload. Continued to track target. The target was
            stopped.

0154        Started to close target. Escort had opened out from target in
            the general direction of TRUK.

0203        Reload completed. Continued to close target at flank speed on
            four engines. The target had gotten underway and was on northeasterly
            course.

0210        Lost contact with the escort,range 14,500 yards.

0238        We had closed to 3600 yards on the target, who was on the port
            bow with a 150 starboard angle.

            The target had been working around to the eastward and it was
            pretty certain that he would have to come to a southerly course
            sometime. It was dark and there was little chance of our being
            sighted outside of 3500 yards. His radar, if he had one, was evidently
            unable to detect us on the first attack. Decided to maintain my
            relative position and wait. Slowed to standard. At this time the
            target was cruising at a speed of 17 knots.

0244        Target turned away on course 030 T. It is now believed that
            we were detected at this time. Followed in target wake after a
            turn away which opened the range. We were able to close slowly at
            flank speed on four engines.

            (Considered firing a zero gyro 180 track shot but decided
            against it because of the high speed and long torpedo run.
            - 8 -

— page 50 —
At this time we should have opened the range to the south,
continued to track, and gained a favorable position for a dawn
periscope attack.

0314 When the range had closed to 2850 yards target opened up with his
after deck gun. Dove.

First salvo landed even with the bow and to port. The quarter-
master observed as he closed the hatch a red flash overhead. There
was an explosion at this time. It was quite possible this was an
illuminating projectile.

0315 I.C. power failed on the way down. When levelling off at a
100 feet, a large up angle resulted when the stern planesmen actually
put full rise on the planes at the time the indicator showed an
incorrect reading of 15 degree dive on the planes. When the
emergency light mechanical indicator showed the planes on full rise,
shifted to hand operation. The boat broached with a 30 degree up
angle.

The boat was brought under control when I.C. power was immediately
restored, and the stern planes shifted to power.

Went to 400 feet.

0335 Screw noises indicated target had opened range. Started to
come up to periscope depth.

0410 Surfaced. Radar contact on the target at 31,600 yards bearing
170 T.

0412 Lost contact of target by radar.

0545 Dove.

1827 Surfaced.

1850 Sent ASPRO serial two.

6 March. 1944

1651 Sighted plane, two engine bomber, flying at low altitude.
Plane crossed our stern close aboard. The sky was overcast. Decided
we had not been detected and did not dive.

1852-30 Observed plane starting to turn. Dove.

1903 At radar depth made contact with the plane dead astern, 6900
yards, closed to 6000 yards. Ordered 100 feet. Before the periscope
went under observed two white lights flash.

1914 At radar depth made SJ contact with plane bearing 120 degrees
relative. Bearing changed to 90 degrees relative and the range
decreased to 5000 yards. Ordered 100 feet.

- 9 -

— page 51 —
1918 One bomb explosion. It was not close but it was close enough
     to convince us he had some pretty accurate means of determining our
     position at radar depth.

2006 At radar depth made SJ contact with plane at 6300 yards. Went
     to 100 feet and decided to come up once every hour.

2108 At radar depth made SJ contact at 1000 yards, range opened
     rapidly to 1600 yards. Went to 100 feet. The operator was positive
     this was a contact and not a wave pip.

2209 At radar depth made SJ contact 70 degrees relative range 2100
     yards, closed to 1650 yards. The commanding officer observed the
     radar screen with the operator and there was no doubt in his mind about
     the authenticity of this contact. The executive officer could see
     nothing through the periscope. Went to 100 feet.

     We had been altering course every hour. Visibility was very
     good, with a bright moon.

2255 At radar depth a careful sweep indicated no contacts on the SJ.
     Started to make preparations for surfacing when radar contact was
     made at 12,500 yards. The range closed rapidly to 7100 yards.
     Ordered 100 feet. Just before the radar was secured the range had
     started to open and the bearing changed rapidly.

2335 Another sweep at radar depth and no contacts. Started to surface
     when SJ contact was made 310 degrees relative, range 13,000 yards.
     Range closed rapidly to 6500 yards while the bearing remained about
     steady. Ordered 100 feet.

     Decided the plane must have some means of DF-ing the radiations
     from our SJ.

7 March, 1944

0028 Made a quick radar sweep with the PPI at 40 feet. No contacts.
     Secured the SJ.

0029 Surfaced. Decided to run with the SJ secured until clear of
     immediate vicinity. Visibility was excellent.

0145 Set an intermittent watch on the SJ taking a sweep with the PPI
     every three minutes.

0155 Radar interference was noted. It seems to be centered about 350
     degrees relative.

8 March, 1944

0943 Sighted large four engine plane through the periscope in low
     power sweep. Went to 100 feet. Plane was close and headed in our
     direction.

- 10 -

— page 52 —
1206 Surfaced. Our own planes based on ENIE ETOK are patrolling to
the north of us. Guarded plane frequency with RBO in order to intercept us
contact reports.

10 March, 1944

0545 Dove.
0949 Surfaced.
1009 Sighted plane on starboard beam about 6 miles distant. Dove.
1155 Surfaced.
1159 Sighted plane on port beam heading for us. Dove.
1830 Surfaced.

12 March, 1944

0832 Pinging (17 kcs) heard by sound. JP reported screws bearing
278 degrees relative.
0840 Periscope observation at 51 feet revealed nothing. Visibility
was excellent.
0850 Screw noises were heard on port quarter and seemed close.
0857 Pinging suddenly seemed quite close. Went to 150 feet.
The pinging had been erratic in that hand keying and automatic keying
was employed. The projector could have been trained away from us
prior to this time, thus accounting for the fact the pinging seemed much
closer. A couple of long hand keyed pings in our direction indicated
that he suspected our presence. Attempted to avoid detection by
keeping our stern toward him.
0948 Tracked target using estimated ranges and bearings of pinging and
determined target must be a submarine, course approximately 125 T.,
speed five knots.

Changed course to put pinging dead ahead.

1040 Pinging, which had become much weaker, either faded out or stopped.
Came to periscope depth.
1221 Pinging was again picked up by sound dead ahead.
1230 Changed course to put contact astern. Pinging was much closer
by this time. It was still all clear through the periscope.
1238 Pinging still closer. Screws were heard astern and seemed close.
It was still clear through the periscope. Went to 150 feet.

As the range closed the submarine continued echo ranging on
automatic 9 second scale. Reciprocal pinging could be heard all around
the dial and the range was estimated to be less than 2000 yards.

- 11 -

— page 53 —
... seemed to be going away on 0.1.
target was heard to tune his sound driver and he seemed to be having
trouble with it as the range opened.

1440 Pinging could no longer be heard. Came to periscope depth.
     Continued on the best estimate of his course, 235 T.
1840 Surfaced.
1929 Abandoned the search. Decided to patrol along the route the
     submarine had been conducting a super-sonic search.

13 March, 1944
0230 Radar out of commission.
0300 Heard distant depth charge. Heard depth charging every half
     hour until 0500.
0530 Radar back in commission.
0546 Dove.
1845 Surfaced.

15 March, 1944
0541 Dove.
0923 Enroute to position 30 miles east of NORTHEAST PASS TRUK, to
     render life guard services.
1836 Surfaced.
2230 Arrived on station for life guard services.

16 March, 1944
0135 Air raid on TRUK commenced. Observed bomb explosions, anti-
     aircraft fire, the red glow from fires started, and heard distant
     airplane motors.
0231 Last anti-aircraft fire observed; raid apparently completed. The
     red glow from the fires started could be seen for the next two hours.
     Nothing was ever heard on the special aircraft frequency.
0430 Radar contact, 60 degrees relative, range 4000 yards, opened out
     rapidly to 9100 yards, 130 degrees relative. This was undoubtedly
     a plane.
0530 Daybreak. Decided to remain on surface and continue to listen on
     the special frequency for information on downed aviators. We had no
     information on whether the air strike was over. To avoid possibility
     of being DF-ed decided not to use SD.
     - 12 -

— page 54 —
0610 Sighted plane distant 12 miles headed for TRUK.
0644 Sighted same type plane distant 10 miles, headed for TRUK.
1026 Sighted plane, distant 9 miles, headed for TRUK.
1208 Sighted plane, distant 4-5 miles on slightly divergent course
     hoaded for TRUK. Plane had come out of rain squall. Dove.
1831 Surfaced. Continued patrol on lifeguard station.

17 March, 1944
1831 Surfaced. Departed life guard station enroute position latitude
     10°-00N, longitude 156°-00E., to make departure from the area.

18 March, 1944
0310 Sent ASFRO serial three.
0523 Sighted plane on starboard beam heading for us. Radar range 8000
     yards. Dove.
1243 Surfaced.
1322 Plane contact on SD radar, 13 miles. C.O.O.D. sighted plane moving
     out on our port quarter.
     Strong interference noted on SD radar. Visibility was excellent.
     Decided to run with the SD secured.
1425 Large silver plane (2 engine bomber) suddenly appeared overhead
     and astern crossing from starboard to port, distant approximately
     3000 yards. He was cruising at a slow speed and had apparently
     came from a high altitude out of the sun. Perfect visibility with
     a cloudless sky makes any other explanation highly improbable.
     Dove. The J.O.O.D. observed the plane starting to bank as he
     was clearing the bridge.
1557 Surfaced.
1604 SD radar contact, 16 miles, closing. Dove.
1655 Surfaced.
2300 Departed area, enroute PEARL HARBOR.

19 March, 1944
0729 Sighted large patrol plane on starboard bow heading for us. Dove.
0806 Surfaced.
1242 SD radar interference.

- 13 -

— page 55 —
1449 Contact on SD, 12 miles. Dove.
1519 Surfaced.
20-28 March, 1944
Enroute PEARL HARBOR. Conducted training and made daily trim dives.
23 March, 1944
0135(K) SJ radar interference noted on port bow.
0225(K) Bearing of interference continued to draw aft.
0335(K) Radar interference faded out.
2325(K) Sighted green rocket on starboard beam. There had been no radar
contact or radar interference noted. This was the correct identification
signal. Turned away and fired a green rocket.
24 March, 1944
0120(L) SJ radar interference noted - not very strong.
0440(L) SJ radar interference again noted. This time it seemed much stronger.
0540 (L) SJ interference faded out.
0620(L) Noted strong SD radar interference.
28 March, 1944
0450 (VW) Rendezvous with escort PC578.
1100 (VW) Moored Submarine Base, PEARL HARBOR.

- 14 -

— page 56 —
(C) WEATHER

Weather in the area north of TRUK was mild throughout the entire patrol.
Skies were generally clear. Wind and sea were generally from the northeast
force 1 to 2. Rain squalls occurred infrequently.

(D) TIDAL INFORMATION

Between TRUK and HALL Islands an inconsistent westerly set was encountered
which averaged about one knot. There appeared to be no appreciable current
north of the HALL Islands.

(E) NAVIGATIONAL AIDS

No navigational aids were sighted.

Landfalls were made on HALL Islands and on the islands of the reef around
NORTH PASS, TRUK.

(F) SHIP CONTACTS (Separate page).

(G) AIRCRAFT CONTACTS (Separate page).

(H) ATTACK DATA (Separate page).

(I) MINES - None encountered.

(J) ANTI-SUBMARINE MEASURES AND EVASIVE TACTICS

Anti-submarine measures are discussed in the narrative. Only general
comments will be made.

The destroyer on the night of 16-17 February detected us by radar. The
high speed and many course changes we were making might be the reason we were
finally forced down by attempted ramming rather than by gun fire. His search
tactics after we were forced down were ineffective. We easily evaded by
running at slow speed under a gradient and keeping destroyer astern.

The night plane contacted on the night of 6-7 March was the most discon-
certing anti-submarine measure encountered. The evidence strongly indicates
the plane had some means of determining our position when our SJ was in
operation at radar depth. We managed to surface and avoided further detection
by running with the SJ secured until clear of the area.

Plane coverage, in spite of recent air raids on TRUK is sufficiently
heavy to make an undetected surface patrol in this area very improbable. No
explanation can be given for the fact that, of the many planes contacted,
we were bombed but one time.

- 15 -

— page 57 —
(F) SHIP CONTACTS
No. | Time-Date | Latitude | Longitude | Type(s) | Initial Range | Estimated Course & Speed | How Contacted | Torpedo Attack No. | Remarks
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
1. | 2100 | 35-12N | 125-45E | Submarine | 8000 (est.) | 100°T | Periscope | 1 | [HANDWRITTEN: Recovered course after changing course to expedite her crossing bow.]
| 2-17-44 | | | | | 12 kts. | | |
2. | 0100 | 35-12N | 125-45E | 3 or 4 ship | 40-450 yds | 100°T | Radar | 1 | [HANDWRITTEN: Forced down by radar equipped ID.]
| 2-17-44 | | | | convoy with | | 7-8 knots | | |
3. | 2254 | 35-12N | 125-45E | Undetermined | 22,000 yds | 100°T | Radar | | [HANDWRITTEN: Possibly radar equipped. Reversed course after changing course to expedite her crossing bow.]
| 2-17-44 | | | | | | 7 knots | | |
4. | 1100 | 8-23 N | 149-1 E | Small 2 | 6,000 yds | 100°T | Periscope | |
| 2-21-44 | | | | sail sampan | | 3 knots | | |
5. | 0955 | 8-23 N | 149-1 E | Patrol | 10 mi. (approx) | 90°T | Periscope | | [HANDWRITTEN: Similar to net tender (long projecting bowsprit)]
| 2-24-44 | | | | Boat | | 5 knots | | |
6. | 0955 | 7-41 N | 151-47 E | Patrol | 4 miles | 90°T | Periscope | | [HANDWRITTEN: Similar to PC]
| 2-26-44 | | | | Boat | | 4 kts. | | |
7. | 1245 | 10-30 N | 152-2 E | Patrol | 4 miles | 20°T | Periscope | | [HANDWRITTEN: Torpedo attack No.2.]
| 2-27-44 | | | | Boat | | kts. | | |
8. | 1752 | 10-30 N | 152-2 E | Passenger [HANDWRITTEN: or Tug] | 9 miles | 90°T | Periscope | |
| 3-3-44 | | | | (Tender) | | [HANDWRITTEN: 5] kts. | | |

- 16 -

— page 58 —
(G) AIRCRAFT CONTACTS

No. | Time-Date | Latitude | Type(s) | Initial Range | Estimated Course | How Contacted | Remarks
    | (-10)     | Longitude |         |               |                  |                 |
----|||||||
1.  | 1129      | 15-10 N   | 1 two   | 6 miles       | 100°T            | periscope       | Sighted while surfac-
    | 2-14-44   | 154-00E   | engine bomber |               |                  |                 | ing. Submerged, but
    |           |           |         |               |                  |                 | failed on waydown.
2.  | 1247      | 15-20 N   | Sameplane as | 4 miles       | 240°T            | Lookout & COD   | Submerged. SD
    | 2-14-44   | 153-52E   | No. 1.  |               |                  |                 | did not pick up
    |           |           |         |               |                  |                 | pick up plane on
    |           |           |         |               |                  |                 | any of those
    |           |           |         |               |                  |                 | contacts.
3.  | 1333      | 15-45 N   | Sameplane | 4 miles       | 240°T            | Lookout         | Submerged. SD
    | 2-14-44   | 153-45 E  | as No. 1 |               |                  |                 | did not pick it
    |           |           |         |               |                  |                 | up.
4.  | [HANDWRITTEN: 0745] | 8-06 N    | 300     | 7 miles       | 090°T            | periscope       | Submerged. SD
    | [HANDWRITTEN: 2-24-44] | 149-37 E  | 4 eng.  |               |                  |                 | did not pick it
    |           |           | bomber  |               |                  |                 | up.
5.  | 0817      | 8-26 N    | Undecided | 6 miles       | 330°T            | Lookout         | Submerged. Plane
    | 2-24-44   | 151-10 E  | 4 eng.  |               |                  |                 | not sighted.
    |           |           | bomber  |               |                  |                 |
6.  | 1110      | 7-46 N    | Zero    | 6 miles       | various          | periscope       |
    | 2-24-44   | 150-51E   |         |               |                  |                 |
7.  | 0805      | 7-45 N    | Zero    | 6 miles       | various          | periscope       |
    | 2-25-44   | 151-45 E  |         |               |                  |                 |
8.  | 0823      | 8-23 N    | 2 eng.  | 1 mile        | 090°T            | lookout         | Appeared to be our
    | 2-25-44   | 151-17E   | bomber  |               |                  |                 | SJ or be equipped
    |           |           |         |               |                  |                 | with radar.
9.  | 1023      | 10-23 N   | Lily    | 5 miles       | 280°T            | periscope       | Not picked up
    | 2-25-44   | 153-02E   |         |               |                  |                 | by SD.
10. | 1831      | 7-30 N    | Betty   | 12 miles      | 090°T            | lookout         | Not picked up
    | 2-25-44   | 152-28 E  |         |               |                  |                 | by SD.
11. | 0943      | 9-21 N    | 4 eng   | 1 mile        | 240°T            | periscope       |
    | 2-26-44   | 152-32 E  | bomber  |               |                  |                 |
12. | 1009      | 9-27 N    | Harris or | 14,000 yds    | 220°T            | periscope       |
    | 3-10-44   | 150-32 E  | Coronado |               |                  |                 |
13. | 1159      | 9-32 N    | 2 eng.  | 8,000 yds     | 270°T            | lookout         |
    | 3-10-44   | 150-37 E  | bomber  |               |                  |                 |
14. | 0644      | 7-30 N    | Betty   | 12 miles      | 270°T            | lookout         |
    | 3-16-44   | 152-28 E  |         |               |                  |                 |
15. | 1026      | 7-30 N    | Betty   | 9 miles       | 260°T            | lookout         |
    | 3-16-44   | 152-28 E  |         |               |                  |                 |

- 17 -

— page 59 —
(G) AIRCRAFT CONTACTS

No. | Time-Date | Latitude | Longitude | Type(s) | Initial Range | Estimated Course | How Contacted | Remarks
--- | --- | --- | --- | --- | --- | --- | --- | ---
| (-TO) | | | | | | | |
1. | 1208 | 7-30 N | 152-28 E | Betty | 8,000 yds | 320°T | lookout |
| 3-16-44 | | | | | | | |
12. | 0523 | 7-30 N | 152-28 E | Betty | 8,000 yds | 335°T | lookout |
| 3-17-44 | | | | | | | |
13. | 1322 | 7-30 N | 152-32 E | Betty | 13 miles | 240°T | lookout & SD radar |
| 3-18-44 | | | | | | | |
19. | [HANDWRITTEN: 0700] | [HANDWRITTEN: 7-58 N] | [HANDWRITTEN: 153-53 E] | [HANDWRITTEN: 2 eng. bomber] | [HANDWRITTEN: 1000 yds] | [HANDWRITTEN: 045°T] | [HANDWRITTEN: lookout & SD radar] |
| [HANDWRITTEN: 3-19-44] | | | | | | | |
20. | [HANDWRITTEN: 1604] | [HANDWRITTEN: 7-44 N] | [HANDWRITTEN: 154-01 E] | [HANDWRITTEN: not sighted] | [HANDWRITTEN: 16 miles] | [HANDWRITTEN: unknown] | [HANDWRITTEN: SD radar] |
| [HANDWRITTEN: 3-18-44] | | | | | | | |
21. | [HANDWRITTEN: 0709] | [HANDWRITTEN: 7-30 N] | [HANDWRITTEN: 153-49 E] | [HANDWRITTEN: 2 eng. bomber] | [HANDWRITTEN: 8 miles] | [HANDWRITTEN: 050°T] | [HANDWRITTEN: lookout] |
| [HANDWRITTEN: 3-19-44] | | | | | | | |
22. | [HANDWRITTEN: 1449] | [HANDWRITTEN: 7-49 N] | [HANDWRITTEN: 153-22 E] | [HANDWRITTEN: 2 eng. bomber] | [HANDWRITTEN: 12 miles] | [HANDWRITTEN: unknown] | [HANDWRITTEN: SD] | [HANDWRITTEN: sighted]
| [HANDWRITTEN: 3-19-44] | | | | | | | |

- 18 -

— page 62 —
(K) MAJOR DEFECTS AND DAMAGE.
No major defects or damage were experienced. The following minor caswalties
are listed for information.

1. The trim pump crank case lub oil cooling water coil ruptured, mixing
salt water with the lub oil. The coil was isolated and the trim pump oil
changed.

2. The trim pump air chamber hose ruptured spraying salt water over the
drain pump controller in the pump room. The drain pump controller grounded out.
The air chamber hose was renewed and its location changed slightly to revent
a repetition of flooding the drain pump controller. This controller was washed
out with fresh water and dried out removing its ground.

3. Both the 2nd stage suction valve on No. 1 H.P. air compressor and the
4th stage suction valve on No. 2 H.P. air compressor broke within a period of
three days. The valves were renewed in each case placing the machinery back
in commission, after a period of about two hours in each case.

4. The motor of No. 2 H.P. air compressor grounded out. The motor was
flushed with fresh water and dried.

5. The forward M.B.T. H.P. air blow valve to the 600 lb. manifold leaked.
A piece of lead under the valve disc had worn a groove in the disc. The
valve was refaced and reseated satisfactorily.

6. The retainer nut on the bearing for the shafting for steering from the
conning tower backed off, causing the shaft to freeze. The nut was reset
satisfactorily.

7. No. 2 I.C. motor generator tripped out twice, once from shock and once
from an undetermined cause. The rolling starting contactor fell from its
running position. Considerable arcing had pitted the roller. It is believed
that the springs which hold the roller in the running position are too weak.
A bakelite block was secured against the roller to prevent further tripping out.
Although this casualty was not serious, it had potentialities. To prevent
further occurrence of this failure the following procedure has been made
effective: Both I.C. motor generators are cut in for battle stations; on
all dives the man who rigs out the bow planes also turns on the emergency bow
plane indicator lights. These lights are turned off again
when the dive is under control.

(L) RADIO

Reception of HAIKU schedules was generally good except from 1800 to 2200
ebrs when signals were generally of low readability ( 1 or 2 ).

On the aircraft frequencies of 3695 and 7920 the signal strength dropped
to S-2 or 3 around 1300 zebra.

A speed key was heard on an aircraft circuit - this practice should be
discouraged in view of the generally poor signal strength of aircraft
transmissions.

- 21 -

— page 63 —
We had a difficult time guarding three frequencies but hope that the
addition of an already authorized RAL receiver will fix it.

(M) RADAR

SD

No material difficulties were experienced with the SD radar. The frequency
with which initial SD contacts closed the ship indicates that it was 77-d.

An intermittent watch was maintained, the SD being turned on for 5 seconds
and off for 25.

The SD was unreliable at times giving contacts as far as 28 miles and at
other times giving no indication even with planes within 2 miles.

SJ-1

Two major material failures occurred on the SJ.

On February 5 a grounded magnetron filament burned out the same resistor
twice before the trouble was located - radar out of commission 5 hours.

On March 13 at 0200 the SJ stopped putting out. The HV milliammeter
current had been slowly increasing for four days and reached a peak of 250 m.a.
The magnetron was replaced. Then the apparatus was turned on again the same
resistor that burned out on February 5 was found to be cooked. Magnetron
filaments were found to be shorted to ground. Magnetron and resistor were
replaced and mediocre results obtained for a few hours until current dropped
to 30 m.a. Found a condenser in the voltage regulator grounded - replaced
condenser. Next attempt to operate showed high current and wide voltage
fluctuation - this was caused by a defective tube. The radar was out of
commission for 41 hours.

It is believed worthy of comment that the attack on the submarine of 15
February was executed entirely by radar. The target was not sighted from the
bridge until after the second torpedo was fired. The zig zag plan had been
determined to such accuracy that the target was zigged on time on the TDC and
continued to generate the ranges and bearings the SJ produced.

Interference was noticeable from time to time throughout the patrol,
particularly during the tracking the nights of 16-17 and 17-18 February and
3-4 March.

The aircraft episode of 6 March indicates the possibility of DF-ing the SJ.
Subsequently the SJ watch made intermittent sweeps of 30 seconds every 3
minutes in order to complicate the DF problem. The sweep was interrupted
by closing the wave guide flapper during the off periods. Everything else in
the equipment was left in its normal operating condition including the power
training.

(N) SOUND GEAR AND SOUND CONDITIONS

Sound conditions were uniformly mediocre throughout the TRUK area.
Propeller noises of a Japanese submarine on the surface were heard on the JK at
an estimated 9000 yards on initial contact.

- 22 -

— page 64 —
The JP propeller noises at an estimated 16,000 yard range.
Pinging of a small patrol vessel was heard at an estimated 12,000 yards.

(O) DENSITY LAYERS

In general the isothermal layer extended to about 3 or 4 hundred feet
throughout the area. However, the following density layers were observed:

| Date | POSITION | TIME | MAX. | TEMPERATURE |
|---|---|---|---|---|
| GCT | Lat. Long | GCT | DEPTH | |
| 2-16-44 | 8-54 N | 1800 | 470 | 79° to 69 1/2° at 360 feet |
| | 149-39 E | | | |
| 2-16-44 | Same as | 2000 | 450 | 79 1/2° to 74° at 330 feet |
| | above | | | |
| 3-3-44 | 9-54 N | 1715 | 470 | 78° to 72° at 300 feet |
| | 154-00 E | | | to 450 feet. |

(P) HEALTH, FOOD AND HABITABILITY

In general the health of the crew was good. One attack of appendicitis
was treated efficaciously. The consumption of vitamin pills was encouraged
and thought beneficial. Ice cream from the ship's freezer added an enjoyable
variation to the menu.

(Q) PERSONNEL

The loyalty and devotion to duty of the officers and crew was in accordance
with the highest traditions of the service.

A very rigorous training schedule was followed throughout the patrol.
Briefly, the training program consisted of daily school periods conducted by
leading petty officers in each compartment. On the return trip new men were
trained in the duties of throttlemen, controllermen, J.O.O. and torpedomen
(in charge of watch), and on the various diving stations. The station bill
was changed to permit the new men to stand instruction watches with more
experienced men. The Executive Officer, Lieutenant J. G. [UNCLEAR: L. S.], USN.,
deserves credit for the development of a well coordinated training program.

Upon arrival at MIDWAY from the first war patrol of this vessel the
required twenty-five percent of the crew was transferred to the relief crew.
Subsequently, and before departure on this patrol, four men (one,
received at MIDWAY who was aboard for training period) were transferred for
various physical disabilities. As a result of these transfers, eighteen
new men were absorbed into the crew, only seven of whom had made previous
patrols. Prior to departure for the area all new men had become well trained
in the duties expected of them. However, with the exception of one
experienced motor machinist mate first class who stood throttle watches, none
of these men were required to fill key positions or to stand watches on
stations where additional training would have been compulsory. The policy of
transferring twenty-five percent of the crew to the relief crew after each
patrol, if he was eligible for transfer until he has completed two patrols
on new submarine, works a particular hardship on a new submarine. A submarine that
has made several patrols has also managed to build up a reserve of personnel

- 23 -

— page 65 —
in the relief crew. The transfer problem then becomes one of leaving in
one section and taking another section out for the next run, with some new
men to fill the gaps left by transfers to new construction. It is strongly
recommended that required transfers to the relief crews from new submarines
be considerably less than twenty-five percent for the first three patrols.

The performance of duty of the crew as a whole was excellent. The following
men are deserving of special mention:

BASS, George Arthur, 279 43 44, CPHM(AA), USN., for his excellent judgement,
conscientious and efficient handling of a very stubborn acute appendicitis case.

LEE, Harold Gordon, 375 91 80, CRM(AA), USN.; SCHLEY, Russell Grant,
664 52 20, RT1c., USNR. both, for their perseverance in solving radar troubles
which contributed materially to the generally excellent performance of the radar.
Their superb operation of the radar on the night of 15-16 February resulted
in the sinking of one J-p submarine.

(R) MILES STEAMED (NAVIGATIONAL) - FUEL USED

Pearl to Area                               3280 miles             40540 gal.
In Area                                     3570 miles             32200 gal.
Area to Pearl                               2885 miles             32610 gal.

(S) DURATION

Days enroute to area                        11
Days in area                                33
Area to Pearl                               10
Days submerged                              28

(T) FACTORS OF ENDURANCE REMAINING

TORPEDOES             FUEL (Gal.)             PROVISIONS             PERSONNEL
14                    5000                    10                     20

Patrol was terminated by operation order.

(U) REMARKS

None

- 25 -

— page 66 —
SUBMARINE DIVISION TWO HUNDRED ONE

A16-3

(028)

C-O-N-R-I-D-E-N-T-I-A-L
FIRST ENDORSEMENT to
C.C. USS ASPRO (SS309) conf.
ltr. SS309/A16-3 Serial (07)
dated 28 March 1944.

From:
To:
Via:
(1)
(2)
(3)

Subject:

1. The second patrol of the U.S.S. ASPRO was of 54 days
duration, thirty-three of which were spent in the area north of Truk. Eight
ship contacts were made but only three of these were targets worthy of
torpedo attack. Of these three contacts the ASPRO was able to press home two
attacks, which resulted in the sinking of an "I" class submarine and of
damaging a large passenger-freighter or tender. This patrol, although the
first for her Commanding Officer, Lieutenant Commander T.A. Stevenson as
commanding officer of a fleet type submarine, was characterized by skillful
planning, aggressiveness and determination. The lack of more contacts can
be attributed to the successful strikes of our surface and air forces during
which the ASPRO had a special mission to perform. The ASPRO was continually
hampered by enemy air patrols, a total of twenty-two air contacts having been
made. The patrol plane encountered on the night of 6-7 February was practical-
ly annoying and indicates that it may have been equipped with radar. The
material condition of the ASPRO on her return from patrol is good and the
morale of officers and men excellent.

2. Attack Number One.

This was a night surface attack, after a daylight end
around, on an "I" class submarine. Four torpedoes were fired from the bow
tubes at a range of 2200 yards. Two hits were observed on the submarine's
bow seen to rise as she sank by the stern. This was a particularly outstanding
attack in that the ASPRO skillfully conducted an end around during the after-
noon of February 15th on a sixteen knot submarine and by 2225 that night had
gained a firing position and determined the zig-zag plan and speed exactly.

- 1 -

Fleet Post Office
San Francisco, Calif.
30 March 1944.

The Commander Submarine Division TWO HUNDRED ONE.
The Commander-in-Chief, United States Fleet.
The Commander Submarine Squadron TEN.
The Commander Submarine Force, Pacific Fleet.
The Commander-in-Chief, U.S. Pacific Fleet.

U.S.S. ASPRO (SS309), Report of War Patrol Number Two -
(Comments on).

— page 67 —
SUBMARINE DIVISION TWO HUNDRED ONE

A16-3
(028)

Fleet Post Office
San Francisco, Calif.
30 March 1944.

D-O-N-F-I-D-E-N-T-I-A-L

Subject: U.S.S. ASPRO (SS309), Report of War Patrol Number Two -
(Comments on).

— page 68 —
SUBMARINE DIVISION TWO HUNDRED ONE

A16-3
(028)

C-O-N-F-I-D-E-N-T-I-A-L

Subject: U.S.S. ASPRO (SS309), Report of War Patrol Number Two -
(Comments on).

5. The Commander Submarine Division TWO HUNDRED ONE congratu-
lates the Commanding Officer, officers and crew of the U.S.S. ASPRO on com-
pleting another highly successful war patrol and recommends that the ASPRO
being credited with inflicting the following damage on the enemy:

SUNK:
One (1) ITEK class submarine - 2180 tons.

DAMAGED:
One (1) passenger-freighter or tender - 11,620 tons.

[SIGNATURE: Gw. Fenno]
F.W. FENNO.

Fleet Post Office
San Francisco, Calif.
30 March 1944.

— page 69 —
SUBMARINE SQUADRON TWENTY
Care of Fleet Post Office,
San Francisco, California,
31 March, 1944.

FC5-20/A16-3
Serial 06
CONFIDENTIAL

SECOND ENDORSEMENT to
CO USS ASPRO (SS309) Conf.
Ltr. SS309/A16-3 Serial 07
dated 28 March, 1944.

From: The Commander Submarine Squadron TWENTY.
To : The Commander-in-Chief, United States Fleet.
Via : (1) The Commander Submarine Force, Pacific Fleet.
(2) The Commander-in-Chief, Pacific Fleet.

Subject: U.S.S. ASPRO (SS309) - Report of War Patrol
Number Two.

1. Forwarded, concurring in the remarks of Commander
Submarine Division 201.

2. The end around run, using the high periscope, and
subsequent sinking of the enemy submarine making sixteen knots,
was particularly well executed.

3. ASPRO's experiences in anti-submarine measures en-
countered should be of especial interest to all Commanding Officers.

4. The Squadron Commander adds his congratulations to
the Captain, Officers and crew of ASPRO on a well conducted patrol
and the damage inflicted on the enemy. It is worthy of note here
that the two brothers who have commanded ASPRO continue to show
the same dogged determination to succeed that they each demonstrat-
ed years ago when the Navy all but retired them for physical
reasons.

LEO L. PACE.

Copy to:
Comsubdiv 201
CO ASPRO

— page 70 —
FF12-10/A16-3(15)/(16)
Serial 0625
CONFIDENTIAL
THIRD ENDORSEMENT to
ASPRO Report of
Second War Patrol.

COMSUBSPAC PATROL REPORT NO. 399
U.S.S. ASPRO - SECOND WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet.
To : The Commander-in-Chief, United States Fleet.
Via : The Commander-in-Chief, U. S. Pacific Fleet.

Subject: U.S.S. ASPRO (SS309) - Report of Second War Patrol.
(3 February to 28 March 1944).

1. The second war patrol of the ASPRO was the first for the new Com-
manding Officer, as such. The patrol was conducted in the area North of Truk.

2. Good area coverage was maintained. Of the three contacts made
worthy of torpedoes, the ASPRO made aggressive and successful attacks on two and was
forced down by a radar equipped destroyer on the third.

3. The sinking of a large Japanese submarine was the result of a bril-
liant end-around run and subsequent well planned attack.

4. In addition to conducting the regular patrol, the ASPRO was assigned
lifeguard duty during the bombing of Truk.

5. It is of note that the ASPRO apparently encountered a Japanese plane
capable of homing on the ASPRO's SJ radar. An effort will be made to determine
some suitable counter measure for this.

6. This patrol is designated as successful for Combat Insignia Award.

7. The Commander Submarine Force, Pacific Fleet, congratulates the Com-
manding Officer, officers, and crew for this aggressive and successful war patrol.
The ASPRO is credited with having inflicted the following damage upon the enemy:

S U N K
1 - Submarine (AI-43 class) - 2,180 tons (Attack No. 1)

D A M A G E D
1 - Passenger Freighter (HEIAN MARU class) - 11,620 tons (Attack No. 2)
GRAND TOTAL - 13,800 tons

Distribution and authentication
on following page.

SUBMARINE FORCE, PACIFIC FLEET 4 01833
[UNCLEAR: Care] of Fleet Post Office,
San Francisco, California
1 April 1944.

NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
ENTERING PATROL AREA.

[HANDWRITTEN: F4253]
[HANDWRITTEN: ①]
[HANDWRITTEN: JHH]
[HANDWRITTEN: 4-21-44]

C. A. LOCKWOOD, Jr.

[HANDWRITTEN: The cdy]
[HANDWRITTEN: s/s]

- 1 -

— page 73 —
[HANDWRITTEN: 1ST COPY]
[STAMP: 8 01365]
SS309/ U.S.S. ASPRO (SS309)

Care of Fleet Post Office,
San Francisco, California,
16 June, 1944.

Serial 012
DECLASSIFIED
[STRIKETHROUGH: C O N F I D E N T I A L]

From: The Commanding Officer.
To : The Commander in Chief, U.S. Fleet.
Via : Official Channels.

Subject: U.S.S. ASPRO (SS309), Report of War Patrol Number Three.

Enclosure: (A) Subject report.
(B) Track Chart.

1. Enclosures (A) and (B), covering the third war patrol of
this vessel conducted in the PALAU area during the period 22 April to 16
June, 1944, is forwarded herewith.

[SIGNATURE: W. A. Stevenson]
W. A. STEVENSON.

[STAMP: DECLASSIFIED]

DECLASSIFIED-ART. 0445, OPNAVINST 5510.1C
BY [HANDWRITTEN: OP-09B6] DATE [HANDWRITTEN: 5/23/72]

[HANDWRITTEN: 82078]

— page 74 —
C-O-N-F-I-D-E-N-T-I-A-L

(A) PROLOGUE

Arrived PEARL HARBOR, T.H. from Second War Patrol 28 March, 1944.
Commenced refit by U.S.S. PROTEUS. Ship was docked, sound tested; deperming
not necessary. Refit completed 14 April, 1944. Conducted training 16-18
April, 1944. Fueled and provisioned ship 19-20 April, 1944. Departed
PEARL HARBOR, T.H. for Third War Patrol 22 April, 1944.

(B) NARRATIVE

22 April, 1944

1321 (VW) Underway from Submarine Base, Pearl Harbor, T.H. for Third War
Patrol in company with escort (PC1077).

1520 (VW) Made trim dive.

2010 (VW) Released escort.

Conducted daily training exercises, fire control drills, emergency
drills, and training dives enroute MIDWAY.

23 April, 1944

1120 (VW) Exchanged recognition signals with PBY.

25 April, 1944

2315 Received orders from Comsubpac to expedite departure from MIDWAY
in order to join another sub at sea to accomplish a special mission.

26 April, 1944

0700 (Y) Joined escort planes enroute MIDWAY.

0800 (Y) Moored starboard side of another sub., at Submarine Base dock,
MIDWAY. Topped off with fuel, lub oil, and provisions.

1130 (Y) Underway from MIDWAY enroute rendezvous with another sub under air
escort.

1433 (Y) Plane escort departed.

27-28 April, 1944

0000 (Y) Crossed 180th meridian, dropped one day from the calendar.

1600 (M) Received orders from Comsubpac cancelling special mission and
rendezvous with other sub. Set course for area.

26 April - 5 May, 1944

Conducted training enroute area; fire control drills, daily
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— page 75 —
C-O-N-F-I-D-E-N-T-I-A-L
training dives, emergency drills, battle surface drills, 20 m.m. gun training.

30 April, 1944
0855 (L) Made practice Battle Surface and fired all guns.

3 May, 1944
1837 (K) Sighted PAGAN ISLAND, 270 T. distant 80,000 yards (radar).
2100 (K) Made passage between PAGAN and ALAMAGAN ISLANDS.

4 May, 1944
1537 (K) Passed through area dense with floating oil drums. There were
hundreds of oil drums. (Latitude 16-14 N; Longitude 141-50 E)

6 May, 1944
0200 (I) Arrived in SPEEDWAY rotating patrol area.
Unless otherwise noted in narrative, all times are zone (-)9.
0510 Made trim dive.
0624 Surfaced. Conducted surface patrol.
1535 Sighted the tops of a ship bearing 158 T. Turned away and went
ahead four engine speed.
1543 Ship identified through the periscope as a large destroyer making
high speed on course approximately 050 T. Attempted to make an end
around keeping ship in sight through high periscope.
1615 Lost sight contact due to poor visibility.
1623 Changed course to 080 T to close the track. The destroyer had
gained bearing on us - the best estimate of his speed was 20 knots.
Decided to hold contact as long as possible and hope for a change of
base course.
1734 Sighted destroyer bearing 112 T. Changed course to open range.
The best estimate of the destroyers course was still 050 T and he was
making more speed than we could make.
1754 Came to the target's base course.
1838 Radar contact bearing 052 T range 13,950 yards, was lost almost
immediately. This had all the characteristics of a plane contact.
1930 Abandoned further search for destroyer.

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— page 76 —
C-O-N-F-I-D-E-N-T-I-A-L
7 May, 1944
0522 Made trim dive.
0645 Surfaced. Conducted surface patrol.

8 May, 1944
0445 Made sight and radar contact on ship, later identified as a
     destroyer bearing 120 relative, 210 T. distant 10,500 yards. The
     destroyer had a large port angle and seemed to be making high speed.
     Went ahead flank speed in an attempt to gain position ahead, before
     daybreak. It was already starting to get light.
0507 Changed course to converge the track 60 degrees. We were too far
     from the track and it was our only chance to gain a firing position.
0510 Forced to dive when target was now visible from the bridge, range
     9400 yards.
0513 Bearing of the target at this time indicated possibility destroyer
     must have slowed or stopped. This possibility was not realized at this
     time. The destroyer was still on the same course.
0516 The destroyer changed course radically and had a 70 starboard
     angle, range 7000 yards.
0517 While changing course to close the track, heard the first of nine
     depth charges. Remained at periscope depth, target was still about 6500
     yards.
     Destroyer continued search tactics consisting of stopping to
     listen and speeding up, steering various courses. The range never
     closed inside 4200 yards.
0530 Destroyer pinged four times.
0600 Destroyer started echo ranging regularly and resumed course and
     speed.
0640 Lost sound contact with destroyer.
0945 Sighted plane through the periscope, distant about six miles.
1832 Surfaced.
11 May, 1944
1040 Sighted large patrol bomber. Dove.
1505 Sighted plane through the periscope distant approximately five
     miles.
1838 Surfaced.

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— page 77 —
C-O-N-F-I-D-E-N-T-I-A-L

12 May, 1944

1058 Sighted large patrol bomber through periscope, distant approximately
     four miles.
1725 Sighted medium bomber plane, distant six miles.
1835 Surfaced.

13 May, 1944

0525 Submerged for periscope patrol.
1000 Sighted large patrol bomber (MAVIS).
1155 Heard distant pinging.
1212 Sighted smoke. Commenced approach.
1229 Sighted stacks of two ships.
1310 Both ships are close to the reef. Continued approach on normal
     approach course.
1358 Broke off approach when unable to close track inside of 4200 yards.
     The best estimate of our position indicated they were less than one
     half mile from the reef. Both targets were the conventional freighter
     type; engine amidships; MKFKM arrangement, composite double deck
     structure. Estimated tonnage, 7500 tons and 6000 tons.
1530 Lost sight contact.
1615 Lost sound contact of pinging.
1840 Surfaced. Went ahead flank speed on two engines to overtake convoy.
1855 Went ahead flank speed on three engines.
2255 Made radar contact, range 21,000 yards. Started an end around
     convoy.

14 May, 1944

0158 Changed course toward convoy. Convoy could be seen from the bridge,
     range 10,000 yards.
0203 Submerged to radar depth.
0214 Periscope depth. Both targets clearly visible through the periscope.
     Only one escort could be seen. The escort was pinging regularly and
     patrolling from side to side ahead of the leading freighter. The two
     freighters were in line of bearing.

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— page 78 —
C-O-N-F-I-D-E-N-T-I-A-L

0219 Sound reported light fast screws close on the port beam.
Sighted another escort with a zero angle.

0219-29 Started firing four torpedoes from the bow tubes; gyro angle ten
degrees left, torpedo run 2500 yards, depth set 8 feet, track angle
80 starboard.

0220 Went to 400 feet.

0224-38 Explosion (possibly end of run)

0225-08 Explosion (another end of run explosion).

No depth charges were dropped. Evidently the convoy was never
alerted by the attack. No explanation can be given for the misses
except the possibility the torpedoes ran under the target. Both
targets appeared to be in the light condition. The TDC set up was
checking right on.

0252 Started up to periscope depth.

0310 Surfaced. Went ahead flank speed on four engines to gain position
ahead for another attack. Radar range - 17,600 yards.

0355 Completed reload. Set depth all torpedoes - 6 feet.

0457 Ahead of convoy. Changed course to head toward the convoy.

0502 Submerged to radar depth.

e should have been approximately 8000 yards off the track of their
base course. However, the convoy evidently changed the base course
and at time of diving we seemed to be right on the track.

0518 Went to periscope depth. We were in an ideal position with a
freighter on either bow.

0528 A zig away put us too far from the track of the leading ship.
Shifted to the trailing freighter, this was the larger of the two.
The formation was the same as before; the larger escort (believe DE type)
was leading the convoy and pinging. The tops of two other escorts
could be seen, one on either quarter of the formation.

0550 Sound reported a torpedo was fired astern. The operator stated
there was no mistaking the sound. The leading escort was dead astern
with a large starboard angle.

0554-30 Explosion (possibly an end of run torpedo explosion). Decided to
fire before the convoy became alerted.

0554-55 Started firing four Mark 18 torpedoes from the stern tubes; gyro
angle twenty left, torpedo run 2500 yards, track angle 53 starboard.

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— page 79 —
C-O-N-F-I-D-E-N-T-I-A-L

0556-55 One very loud explosion as we were passing 100 feet. This was
           a hit for number one torpedo.

0559-30 First of twelve depth charges during next six minutes. Evaded
           by running at two thirds speed at 400 feet and keeping all contacts
           abaft the beam.

0614       Single charge - not close.

0629       Started to come up to periscope depth.

0636       Depth charge - not close.

0646       Planed down to 350 feet when sound reported screws of escort
           getting closer.

0714       At periscope depth. Sighted ship in direction of pinging. Changed
           course to head for target group. Commenced reload.

0737       Both ships are visible. The damaged ship is down by the stern.
           Both ships are dead in the water. The escorts can not be seen, but
           pinging can be heard and they are apparently searching. A plane
           (LILY) is circling the two marus.

           The visibility is excellent, and the sea a glassy calm. Continued
           to close.

0820       The damaged ship is further down by the stern. The bow is at an
           angle of 35-40 degrees. The plane is still circling. Changed course
           to put target group on port beam.

0845       Damaged ship continued to settle by the stern. No attempt was
           being made to get her in tow. Went to 150 feet when the plane headed
           in our direction.

0848       Bomb explosion. This was not very close and quite possibly was
           not meant for us.

0900       JP reported dull explosions in the direction of the target. The
           damaged freighter must have sunk at this time.

0925       At periscope depth, only the one ship could be seen. The
           remaining ship was still lying to. The plane was still there.

0935       The ship was underway now on course 300 true.

1055       Lost sight contact with freighter.

1400       Lost sight contact with smoke.

1430       Sighted plane (LILY) distant about four miles.

1842       Surfaced. Went ahead flank speed on two engines to regain contact
           with remaining maru.

- 6 -

— page 80 —
C-O-N-F-I-D-E-N-T-I-A-L

1935 Flank speed on three engines.
2058 Flank speed on four engines.
2150 Picked up SJ radar interference, 330 relative.
2200 Made radar contact; range-26,700 yards, bearing - 339 relative.
     Started an end around.
2315 Radar contact, 350 relative, range 12,000 yards. Turned away and
     opened the range. This was the center of the radar interference and
     we were reasonably certain this was a friendly submarine.
2330 Came to the targets base course and decided to maintain present
     position. If this was a friendly submarine, he should be making his
     attack soon.

15 May, 1944

0014 The range to the target had increased to 28,000 yards. The radar
     interference seemed to center on about the same relative bearing.
     Changed course to converge the target track about thirty degrees.
0020 Radar contact sharp on the port bow, 11,500 yards. Turned away
     until contact was lost and resumed base course.
0040 Attempted to close track and again contact was made about 12,000
     yards and we were forced to turn away. We had been making four engine
     speed and were beyond radar range of the freighter.
0108 Decided what we were mistaking for a friendly submarine was
     actually a radar equipped escort. Submerged in an attempt to shake
     him.
0159 Surfaced. Range to the freighter 22,000 yards.
0210 Contacted radar escort again at 12,500 yards between us and the
     target. Turned away to open the range.
0212 Changed course to the reverse of the targets base course.
0220 The escort, instead of drawing aft, gained bearing and again
     contact was made. Turned away.
0223 Turned toward target.
0225 Dove to radar depth and commenced approach.
0246 Periscope depth.
0308-42 Started firing four Mark 18 torpedoes from stern tubes; gyro
     angle ten left, torpedo run 1800 yards, track angle 95 starboard.

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— page 81 —
C-O-N-F-I-D-E-N-T-I-A-L

0309 Started to go deep when the escort on the starboard quarter of
the target speeded up. An observation before firing showed he had a
small angle.

0310-30 Very loud explosion. Hit.

0310-57 Explosion, could be heard through hull but was not as loud as first
torpedo explosion. This was a hit for fourth torpedo fired.

0315-0325 Twelve depth charges. None very close. Evaded by running at two
thirds speed at 400 feet and keeping all contacts abaft the beam.

0400 Single depth charge.

0547 Single depth charge.

0549 Single depth charge.

0557 At periscope depth, sighted damaged ship. Changed course to head
for ship.

0558 Three depth charges.

0602 Two more depth charges.

0631 Three depth charges.

Ship is down by the stern and has a slight starboard list.

0729 The damaged ship continued to settle and the list had increased.
The escorts continued to search the area.

0825 The three escorts could be seen; they were conducting a search
to the west of the target. Sighted a plane (LILY) circling the damaged
ship. A lifeboat was alongside the starboard side. The ship was
slowly but definitely settling. Decided to continue approaching from
the eastward and to finish the job with a couple of torpedoes from the
bow tubes.

0936 Fired two bow tubes at an estimated range of 3400 yards, zero
gyro angles, track angles 95 starboard. Went to 400 feet immediately
after firing and changed course 90 degrees to get off torpedo track.

0941-05 Explosion.

0941-24 Explosion.

Both of these were probably end of run explosions. They could
have run under the target near the bow which was at an angle of approx-
imately 25 degrees by this time. It was also quite possible that the
range was badly underestimated and one of the torpedoes hit. A later
observation of the target seemed to prove this theory. Since these
explosions were so near the time the depth charging started, it is also

- 8 -

— page 82 —
C-O-N-F-I-D-E-N-T-I-A-L

quite possible that these were depth charges and the actual torpedo
explosions were never heard.

0941-45 Received twelve depth charges in the next three minutes.

1112 At periscope depth. The damaged ship was still afloat. Changed
course to head for the crippled ship.

1228 The plane was still circling the target. The heading of the target
had changed approximately 130 degrees to the right. The ship was
still dead in the water and the list had increased.

1305 Two planes were seen circling the target.

1400 Lost contact with the pinging. The escorts evidently had departed.

1507 One plane sighted at this time.

Maintained position about 16,000 yards from target.

1800 Came up to 40 feet. Nothing in sight but the target. Took some
periscope pictures.

1852 Surfaced and started to close the target. The target was still
visible from the bridge without the aid of binoculars. Made preparations
to sink the cripple with the deck gun.

1901 Target sunk. Observed by commanding officer, executive officer,
and bridge personnel. Radar contact was lost, and about this same
time people below decks reported a rumbling explosion. Continued to
close scene.

1922 Slowed in the vicinity of the sinking. It was dark now and a
rain squall had reduced the visibility.

1928 Picked up very strong radar interference.

1931 Made radar contact, 11,800 yards. Decided this was probably a
friendly submarine. Changed course to open the range and to return to
our area.

We now wondered if our cripple was finished off by a torpedo from
one of our own submarines. We were tired, but, after the prolonged
chase, we would have enjoyed sinking the cripple with the deck gun.

16 May, 1944

2203 We had just slowed and had started to man sound gear when lookout
reported a dark object on starboard bow. Turned away and opened range.

2205 Made radar contact with two ships, 4800 yards and 5200 yards, on
very nearly the same bearing. The pips were difficult to see, even at
this range. Decided the contacts were either small patrol boats or
sampans.

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C-O-N-F-I-D-E-N-T-I-A-L

2257 Stopped and manned the sound gear to determine if possible
     whether the contacts were patrol boats on routine search.

     A plot of their course and speed showed they were making six knots
     on course 060 true.

2331 Made radar contact at 12,350 yards. Picked up one set of light high
     speed screws. Continued to track targets on course 060 true at six
     knots.

2338 Changed course away and opened range.

2350 Abandoned further search and headed for our area. It was
     apparent that the contacts did not warrant torpedo expenditure.

28 May, 1944

0505 Picked up echo ranging by sound. No contact by radar.

0530 Sighted outline of ship. Changed course away to open range.
     Identified the contact as three escorts; two small escorts and one
     larger escort, later identified as a DE. It was now getting fairly
     light. There were no other contacts. They were still beyond radar
     range, at an estimated range of 22,000 yards.

0540 Submerged when the larger escort apparently sighted us and headed
     in our direction.

     Remained at periscope depth and observed DE close the range at
     high speed, estimated 20 knots (240 rpm). He had secured echo ranging.

0609 Pattern of four depth charges when the escort was at a range of
     6500 yards.

0611 DE started pinging, and continued to search at high speed on
     various courses. He never closed the range inside of 6500 yards.
     Remained at periscope depth.

0634-0636 Eighteen depth charges. Estimated range four miles.

0700 Lost sight contact with DE.

0732 Six more depth charges.

1020 Lost contact with echo ranging.

1145 Three depth charges.

1154 Pinging again heard.

1205 Lost contact with echo ranging.

1839 Surfaced.

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— page 84 —
C-O-N-F-I-D-E-N-T-I-A-L
2030 Received orders from Comsubpac that we were to proceed
to FREMANTLE for refit upon departure from area.

5 June, 1944
1000 Sighted two planes (RUFE) through periscope, distant six
miles.
1841 Surfaced.
2130 Departed area and headed for Lat. 5°-00 N, Long. 130-00 E.

6 June, 1944
1519 Sighted unidentified plane Dove.
1616 Surfaced.
1700 Departed PALAU area.

7 June, 1944
0900 Passed to operational control of ComTask Force Seventy-One.
Shifted radio guard to Radio PERTH.
0922 Dove on sight contact with plane.
1000 Surfaced.
1033 Plane contact on the SD, six miles. Dove.
1121 Surfaced.
1502 Made sight and radar contact with plane (BETTY), eight miles. Dove.
1517 Surfaced.
2100 Started passage of MOLUCCA PASS.
2250 Made plane contact on SJ, six miles. Dove.
2305 Surfaced.

8 June, 1944
0700 Crossed equator.
1014 Submerged. Conducted "crossing the line" ceremony.
1100 (H) Change to (-)8 zone time.
1122 (H) Surfaced.

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C-O-N-F-I-D-E-N-T-I-A-L

2330 (H) Sighted small sampan. Changed course away and opened range.
          Radar contact was never made.

9 June, 1944

0706 (H) Plane contact on SD, nine miles, closing. Dove.
0732 (H) Surfaced.
0746 (H) Dove on sight contact with unidentified plane, approximately
          seven miles.
0800 (H) Surfaced.
2330 (H) Started passage of OMBAI STRAIT.

10-14 June, 1944

          Enroute EXMOUTH GULF to obtain fuel. Conducted daily trim dives
          and training enroute.

14 June, 1944

0615 (H) Contacted escort plane. Exchanged recognition signals.
0855 (H) Moored port side to oil barge, EXMOUTH GULF. Received 11,000
          gallons fuel.
1103 (H) Underway from alongside oil barge, enroute FREMANTLE under air
          escort.
1535 (H) Escort plane departed.

15 June, 1944

0803      Sighted submarine, identified through high periscope as a friendly
          submarine. Submarine was on opposite course distant about seven miles.
          Attempted to exchange recognition signals. Fired rocket signal.
0928      Made trim dive.
0946      Surfaced.

16 June, 1944

1015      Rendezvoused with surface escort SC 739 and plane escort.
1300      Moored FREMANTLE.

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— page 86 —
C-O-N-F-I-D-E-N-T-I-A-L

(C) WEATHER

In the PALAU area the skies were overcast about 40 percent of the time.
The sea was a glassy calm at least 80 percent of the time and never exceeded
condition two. Cloud formations were predominantly strato-cumulus. Rain
squalls were encountered frequently with at least one squall within radar range
almost continuously. These were generally light however.

(D) TIDAL INFORMATION

North, west, and south of the PALAU group the current set westerly with a
velocity of about one knot. Inshore, to the west of the group, the current was
variable, a northerly set of 2 knots being encountered off the western side
of northern BABELTHUAP ISLAND. Farther west of the group a westerly set was in
evidence. All currents were quite irregular, but the above is believed to strike
an average.

(E) NAVIGATIONAL AIDS

No navigational lights were sighted. A white light of undetermined
characteristics was seen for a short time in the vicinity of eastern
URUKTHAPEL ISLAND. It cannot be said for a certainty that this was a navigational
light.

A prominent tower is located on a hill on BABELTHUAP ISLAND. It is
believed that this is the hill marked AIYON on HO Chart 5423. Difficulty
was experienced in cutting in any of the peaks however.

(F) SHIP CONTACTS (Separate page).

(G) AIRCRAFT CONTACTS (Separate page).

(H) ATTACK DATA (Separate page).

(I) MINES - No mines were encountered

(J) ANTI-SUBMARINE MEASURES AND EVASIVE TACTICS

The anti-submarine vessels encountered were extremely ineffective
in search and attack after we were submerged. No new tactics or methods
of search and attack were encountered. The usual practice of dropping
charges in the vicinity of the submarine after an attack or sighting was
pursued. After the initial depth charging, echo ranging on 17 kcs and
stopping to listen was the standard procedure. A total of eighty-nine
depth charges were intended for the ASPRO this patrol. No very close
depth charges were received and there was never any indication that contact
was made by the anti-submarine vessels once we were submerged. This was
surprising in view of the excellent sound conditions that prevailed in
the area. Twice we were sighted on the surface at dawn, once by a destroyer
and once by a DE. We may have been detected by radar, but there is the
possibility their lookouts are becoming more proficient.

- 13 -

— page 87 —
C-O-N-F-I-D-E-N-T-I-A-L

     There is insufficient evidence to state that the contact on the morning
of 15 May that continued to prevent our closing the freighter, was an escort.
Radar interference was encountered on the bearing of this contact; however,
there is the possibility that this could have been one of our own
submarines.

     The escort that patrolled on the quarter of the convoy was a disconcerting
factor in the final stages of an approach. We always managed to reach firing
position on one of the freighters right on the escort's track. We would be
forced deep following an attack because we were never certain whether this escort
had detected us.

     The planes encountered were all detected before we were apparently
sighted. This attests to the excellent work of the lookouts throughout the
patrol.

(K) MAJOR DEFECTS AND DAMAGE

     There were no major defects and no damage was sustained. Following
minor casualties are listed for information.

     1. Early in the patrol No. 1 periscope lighting grounded out due to sea
water leakage through periscope packing gland.
     2. The gasket on negative tank vent was blown from its retainer ring.
The excessive pressure was due to the failure of the hydraulic manifold operator
to close negative flood after it had been blown while going deep.

     3. Both I.C. motor generator commutator slip rings became badly burned.
The trouble is attributed to either a flat or soft spot on the rings, or
insufficient brush tension.

     4. Lub oil leaks into the auxiliary generator, and is thrown off by the
flywheel. The resultant vapor being circulated through the generator
necessitates frequent two day decommissioned cleaning periods.

     5. On the second consecutive patrol poppet roller cranks (Dr. 261171
Pc 3) for torpedo tubes have been found inoperative due to corrosion.
Galvanic action is believed to cause the trouble. It is recommended that boats
carry spares of this part on patrol and that the possibility of manufacturing
the crank of some less susceptible material be investigated.

     6. The lead-in for the starboard wing antenna carried away probably
while the boat was at radar depth. This was temporarily repaired by ships force.

(L) RADIO

     Reception of the H.I.K.U. fox schedule was good except between 1900 and
2200 GCT when signal strength was 1 or 2. The best listening frequency was
9090 kcs.

     NPM could not be raised from the area on 8470 kcs during a 45 minute trial,
but the message was immediately cleared on 4235 with no difficulty.

                                  - 14 -

— page 88 —
C-O-N-F-I-D-E-N-T-I-A-L
Reception of the BAKERS fox schedule was poor (signal strength 2) during
the passage between MOLUKKA and OMBAI but was strength 4 or 5 before and
after. A transmission was completed with no difficulty south of OMBAI STRAIT.

(M) RADAR

The total time spent finding and remedying casualties on the SJ was about
one hour out of approximately 575 hours in use. This speaks well for the
increasing reliability of the materiel and personnel. Ranges on high land
were estimated at 120,000 yards. SJ performance was highly satisfactory.

The SJ continues to be a hit or miss proposition. Of the plane contacts
on the surface half were picked up by the lookouts and half by the SJ. We
will continue to pamper our lookouts.

(N) SOUND AND SOUND CONDITIONS

Sound conditions in the PALAU area are phenomenal. Propellers were
heard up to 15,000 yards by QC and JK and an estimated 20,000 yards by JP.
Echo ranging was heard at an estimated 40,000 yards. Sound search at night
was resorted to with some success when pinging was picked up while the ships
were still outside of radar range.

(O) DENSITY LAYERS

In general, no density layers were observed on routine dives to a depth
of 150 feet.

The only density layer found was observed as follows:

| Date | Position | Time | Max | Temperature |
|---|---|---|---|---|
| GCT | Lat. Long. | GCT | Depth | |
| 13 May, 1944 | 8°-0' N | 1700 | 425 feet | 83° at 340' dropped |
| | 133° E | | | to 77.5° at 400' |

(P) HEALTH FOOD AND HABITABILITY

The health of the crew was excellent.

Light noon meals were tried during days submerged and in warm weather and
were well received. The commanding officer believes that curbing the tendency
to overeat from boredom has a beneficial effect on the crew. The importance of
ice cream and fresh frozen vegetables on the menu cannot be overemphasized.

(Q) PERSONNEL

Performance of duty of all hands was exemplary. The period 13-15 May
during which we were in contact with a convoy almost continuously and at battle
and tracking stations for long periods was tiring. The crew stood to their
task in commendable fashion. The training period before this patrol was the
shortest we have had yet. That it was adequate was due to the fine leadership
and effort displayed by Torpedoman GAETANA and the interest shown by the new
men. With few exceptions the caliber of relief crew are, if not their knowledge,
continues high.

- 15 -

— page 89 —
C-O-N-F-I-D-E-N-T-I-A-L

The alertness and attention to duty of the lookouts has been
particularly commendable. While their importance has been continually stressed
by the officers, it is believed that the high standard maintained by a group
of petty officers - gunners mates, torpedomen and yeoman, who have stood
these watches for three patrols has been the dominant factor in eliciting the
same high standard of performance by the less experienced men. The alertness
of the lookouts saved the ship from possible embarrassment by small patrol
boats on at least three occasions and by aircraft on several others.

Number of men qualified at beginning of patrol             51
Number of men qualified during patrol                      11
Number of men advanced in rating during patrol             16
Number of men unqualified at end of patrol                  7

A system of training was instituted this patrol whereby all qualified men
were required to lecture to unqualified men on various compartments (previously
only officers and CPO's lectured). Qualified men, by their own admission,
benefitted greatly by this procedure since they were assigned compartments in
which they normally stand no watches.

A point of interest - new seamen invariably know nothing of steering the
boat or of the phraseology employed in giving and acknowledging orders to the
wheel and engines. As a result Q.M.'s and C.O.P.'s have their hands full the first
few days out.

(R) MILES STEAMED - FUEL USED

Pearl to Area             4021 miles             42637 gal.
In area                   4523 miles             33533 gal.
Area to Fremantle         3076 miles             31000 gal.

(S) DURATION

Days enroute , area 14
Days in area             31
Days enroute Fremantle 11
Days submerged         26

(T) FACTORS OF ENDURANCE REMAINING

TORPEDOES             FUEL             PROVISIONS             PERSONNEL
10                    6500*            15                     15

* On arrival EXMOUTH GULF.

Limiting factor - Patrol terminated by operation order.

(U) REMARKS

No remarks.

- 16 -

— page 90 —
C-O-N-F-I-D-E-N-T-I-A-L
(F) SHIP CONTACTS

No. | Time | Lat. | Type | Initial | Est.Course | How Con | Remarks
    | Date | Long. |      | Range   | Speed      | tact    |
----|------|------|------||||
1   | 1535 | 9-10N | DD   | 18000   | 070°T      | Sight   |
    | 6 May| 136-11E|      | yards   | 17-18 kts  | lookout |
2   | 0445 | 9-05N | DD   | 10,150  | 060°T      | Sight   |
    | 8 May| 137-29E|      | yards   | 17-18 kts  | lookout |
3   | 1229 | 7-30N | Convoy| 12,000  | 020°T      | Sound   | Pinging heard 1/2 hour
    | 13 May| 134-44E| 2 DD | yards   | 8 kts      |         | before sighting by
    |      |      | 1 AK |         |            |         | periscope
    |      |      | 1 PC |         |            |         |
3a  | 2255 | 8-52N | Same as| 20,000  | zigging on SJ radar
    | 13 May| 134-22E| #3 with| yards   | base course
    |      |      | 1 or 2|         | 320°T
    |      |      | more esc|         | 8.5 kts
    |      |      | orts |         |            |         |
3b  | 2200 | 9-38N | Same as| 26,700  | zigging on SJ radar
    | 14 May| 132-03E| #3 less| yards   | base course
    |      |      | 1 AK |         | 300° T
    |      |      |      |         | 8.5 kts.
4   | 2315 | 9-58N | Unknown| 12,000  | Approx     | SJ Radar| Believed to be friendly
    | 14 May| 131-46E|      | yards   | 290°T      |         | submarine tracking
    |      |      |      |         |            |         | target-SJ interference
    |      |      |      |         |            |         | present;or radar equip-
    |      |      |      |         |            |         | ped escort.
5   | 1931 | 10-11N| Unknown| 11,800  | Approx.    | SJ radar| Believed to be friendly
    | 15 May| 131-21E|      | yards   | 180°T      |         | sub-SJ interference
    |      |      |      |         | 12 kts     |         | present.
6   | 2203 | 7-23N | Unknown| 4800,   | 070°T      | Lookout | Sighted by lookout
    | 16 May| 131-50E|      | 5200 yds| 6 kts      |         | before SJ. Believed to
    |      |      |      |         |            |         | be 2 sampans patrolling
7   | 0505 | 7-22N | 3 escorts| [UNCLEAR: est.]| 255°T      | Sound   |
    | 28 May| 131-39E|      | 10 miles| 10 kts     |         |
8   | 0215 | 7-58N | Patrol | 6500    | ---        | Lookout | Only momentary radar
    | 6 June| 133-28E| Boat or| yards   |            |         | contact
    |      |      | Sampan |         |            |         |
9   | 2330 | 2-46S | Sampan | 8000 yds| ---        | Lookout |
    | 8 June| 125-44E| or Patrol| est.    |            |         |
    |      |      | boat |         |            |         |

- 17 -

— page 91 —
(G) AIRCRAFT CONTACTS

No. | Time | Lat. | Type | Initial | Est. | How con- | Remarks
    | Date | Long. |      | Range   | Course | tacted   |
----|------|------|------||||
1   | 0945 | 9-14N | Betty | 6 miles | 075°T | Periscope |
    | 8 May | 137-39E |      |         |        |          |
2   | 1040 | 6-52N | Mavis | 8 miles | 165°T | Lookout  |
    | 11 May | 135-52E |      |         |        |          |
3   | 1505 | 6-39N | Lily | 5 miles | 325°T | Periscope |
    | 11 May | 135-33E |      |         |        |          |
4   | 1058 | 7-04N | Betty | 4 miles | 335°T | Periscope |
    | 12 May | 134-38E |      |         |        |          |
5   | 1725 | 6-56N | Medium | 5 miles | 320°T | Periscope |
    | 12 May | 134-37E | Bomber |         |        |          |
6   | 1000 | 7-35N | Mavis | 4 miles | 220°T | Periscope |
    | 13 May | 134-47E |      |         |        |          |
7   | 0820 | 9-05N | Medium | 5 miles | circling | Periscope | Plane circling hit ship
    | 14 May | 133-27E | Bomber |         |        |          | of convoy. Ship
    |        |         |      |         |        |          | contact #3a
8   | 1430 | 9-12N | Lily | 4 miles | 160°T | Periscope |
    | 14 May | 133-19E |      |         |        |          |
9   | 1228 | 10-10N | 2 Lily | 3 miles | circling | Periscope | Circling hit ship of
    | 15 May | 131-28E |      |         |        |          | convoy in ship contact
    |        |         |      |         |        |          | No. 3b
10  | 1000 | 8-35N | Rufe | 6 miles | 045°T | Periscope |
    | 5 June | 135-05E |      |         |        |          |
11  | 1519 | 6-12N | Uniden | 9 miles | --- | Lookout  |
    | 6 June | 131-20E | tified |         |        |          |
12  | 0922 | 3-22N | Fighter | 6 miles | 120°T | Lookout  |
    | 7 June | 127-56E |      |         |        |          |
13  | 1033 | 3-17N | Uniden | 6 miles | Unknown | SD Radar |
    | 7 June | 126-49E | tified |         |        |          |
14  | 1502 | 2-41N | Betty | 8 miles | 270°T | SD Radar |
    | 7 June | 126-55E |      |         |        |          | & Lookout
15  | 2250 | 1-37N | Uniden | 6 miles | 000°T | SJ Radar |
    | 7 June | 125-50E | tified |         |        |          |
16  | 0706 | 4-24S | Uniden | 9 miles | unknown | SD Radar |
    | 9 June | 125-07E | tified |         |        |          |
17  | 0746 | 4-28S | Betty | 7 miles | 090°T | Lookout  |
    | 9 June | 125-07E |      |         |        |          |

- 18 -

— page 92 —
C-O-N-F-I-D-E-N-T-I-A-L
(H) ATTACK DATA (Cont)
U.S.S. ASPRO (SS309) TORPEDO ATTACK No. 4 PATROL No. 3
TIME: 0936 (I) DATE: 15 May, 1944 LAT.: 10-10 N LONG.: 131-25 E
DESCRIPTION: Same as Attack No. 3
SHIP SUNK: Same as Attack No. 3

DAMAGE DETERMINED BY: Damage, if any from this attack was never determined.
Earlier observation of the already crippled Maru indicated a
change of heading of approximately 130 degrees. The list had
increased and the cripple was lower in the water.

TARGET DRAFT: 14' (mean) Dead in Water RANGE: 3400

OWN SHIP DATA

SPEED 3 COURSE: 266° T DEPTH: 60 ft.

FIRE CONTROL AND TORPEDO DATA

TYPE ATTACK: Headed for target, dead in the water, and fired with
gyro angles set on zero.

| | 1 | 2 |
|---|---|---|
| Tubes fired | 1 | 2 |
| Track Angle | 95 S | 95S |
| Gyro Angle | 0 | 0 |
| Depth Set | 6 ft | 6ft |
| Hit or Miss | One possible hit |
| Erratic | No | No |
| Mark torpedo | 23 | 23 |
| Serial No. | 61765 | 61766 |
| Mark Exploder | 64 | 64 |
| Serial No. | 21772 | 21843 |
| Mark Warhead | 16-1(TPX) | 16-1 (TPX) |
| Serial No. | -- | -- |
| Firing Interval | 10 second |
| Type Spread | None |
| Sea Condition | Calm |
| Overhaul Activity | -- U.S.S. PROTEUS -- |
| Remarks: | None |

- 19 -

— page 95 —
C-O-N-F-I-D-E-N-T-I-A-L

(H) ATTACK DATA

U.S.S. ASPRO (SS309) TORPEDO ATTACK No. 1 PATROL No. 3

TIME: 0219 (I) DATE: 14 May, 1944 LAT.: 9-00N LONG.: 134-00E

DESCRIPTION: Made original contact by sound - heard echo ranging. Surfaced
at dark and over look convoy. Made night periscope approach. Sea was
calm, moon was up.

The convoy consisted of two AK's and three escorts. The AK's
were both the conventional coal burning freighter type; engine amidship,
composite structure, MKFKM arrangement, estimated tonnage - 7500 tons
and 6000 tons. They were both in the light condition. Two of the escorts
were PC type or similar; the larger escort was unidentified but believed
to be a DE.

SHIP SUNK: None

SHIP DAMAGED: None

TARGET DRIFT: 9' (light) COURSE: 270°T SPEED 8.5 Knots. RANGE: 2600 yards

OWN SHIP DATA

SPEED: 4 knots COURSE 180°T DEPTH: 60 feet

TYPE ATTACK: This was a night periscope attack after period of tracking
on the surface and at radar depth.

| | 1 | 2 | 3 | 4
|Tubes fired | 1 | 2 | 3 | 4
|Track angle | 80 S | 80 S | 80 S | 84 S
|Gyro angle | 10 L | 10 L | 10 L | 6 L
|Depth Set | 8 ft. | 8 ft | 8 ft | 8 ft
|Hit or Miss | Miss | Miss | Miss | Miss
|Erratic | No | No | No | No
|Mark Torpedo | 23 | 23 | 23 | 23
|Serial No. | 61865 | 61774 | 61909 | 61798
|Mark Exploder | 6-4 | 6-4 | 6-4 | 6-4
|Serial No. | 21849 | 21802 | 21829 | 21781
|Mark Warhead | 16-1(TPX) | 16-1(TPX) | 16-1(TPX) | 16-1(TPX)
|Serial No. | 9356 | 13272 | - - - | - - -
|Firing interval | 0 | 11 | 10 | 13
|Type spread | 1/2 R | 1/2 L | 1 1/2 L | 1 1/2 R
|Sea Conditions | - - - - - - - CALM - - - - - - -
|Overhaul Activity | - - - - - - - U.S.S. PROTEUS - - - - - - -
Remarks: Torpedo performance was apparently normal, although only two end of
run explosions were heard. The TDC set up had been checking
perfectly before firing. It is believed the torpedoes ran under the
target.

- 22 -

— page 96 —
[STAMP: - 8 01365]
FC5-12/A16-3

Serial 095

CONFIDENTIAL
FIRST ENDORSEMENT to
U.S.S. ASPRO - Report
of Third War Patrol.

SUBMARINE SQUADRON TWELVE
                                        Care of Fleet Post Office,
                                        San Francisco, California,
                                        22 June 1944.

From: The Commander Submarine Squadron TWELVE.
To : The Commander-in-Chief, United States Fleet.
Via : (1) The Commander Submarines SEVENTH FLEET.
      (2) The Commander SEVENTH FLEET.

Subject: U.S.S. ASPRO (SS309) - Report of Third War Patrol -
         Comments on.

         1. The Third War Patrol of ASPRO occupied a period of 56
days, of which 38 days were spent in enemy-controlled waters while
enroute from Pearl Harbor to Fremantle, via Palau and the Moluccas.
The patrol was terminated by provisions of the operation order.

         2. There were three contacts with enemy ships or groups
thereof which were worthy of torpedo fire. The first and second con-
tacts were with destroyers which got around ASPRO at high speed. The
third contact was with an escorted convoy of two freighters against
which ASPRO delivered four persistent attacks during a period of 50
hours, as follows:

         (a) Night periscope attack after a 3½ hour period of tracking
on surface and at radar depth. This was a four torpedo salvo directed
against one AK making 8.5 knots, from 2600 yards with track angle of
80° starboard. Activity of one of the escorts prevented improving the
firing position and precipitated an early firing which resulted in no
hits. It is noted that torpedoes were set at eight feet. It is believed
that in a night attack on unidentified targets torpedoes should never
be set to run deeper than six feet.

         (b) ASPRO made an "end around" and again attacked the larger of
the two freighters (dawn periscope attack) from a range of 2500 yards
with a 53° track. The attack was again hurried; on this occasion by
the fact that sound reported a torpedo fired astern of ASPRO, subsequent
to which there was an explosion timed at about 4½ minutes. One Mark 18
hit from four fired was obtained and the ship sank about three hours
later.

         (c) After about another day of chasing, ASPRO achieved a most
satisfactory firing position and obtained two Mark 18 hits from a
salvo of four torpedoes in a night periscope attack after surface and
radar-depth tracking. Track angle 95°, range 1800.

                                        - 1 -

— page 97 —
FC5-12/L16-3
Serial 095

CONFIDENTIAL
FIRST ENDORSEMENT to
U.S.S. ASPRO - Report
of Third War Patrol.

Subject: U.S.S. ASPRO (SS309) - Report of Third War Patrol -
Comments on.

(d) This was a salvo of two Mark 23 torpedoes fired from a range
of 3400 yards with a track angle of 95° at the ship crippled in attack
No. 3 lying dead in the water. The presence of an airplane and three
escorts contributed to the excessive firing range. No definite hits
were obtained but the ship sank 16 hours after attack number 3.

3. On several occasions the tactical activity of ASPRO
was hampered by SJ radar interference which might have emanated from
a friendly submarine. The need for a ready means of identification
by means of SJ radar is apparent. In the absence thereof, it is be-
lieved that friendly submarines should identify each other by voice
radio.

4. It is noted that ASPRO was twice sighted on the sur-
face at dawn, once by a destroyer and once by an escort. Submarines
engaged in tracking by radar during the night must usually draw out
of radar range as dawn approaches in order to continue the tracking
by high periscope undetected after daylight; and, likewise, sub-
marines engaged in tracking by high periscope must gradually move
into radar range as dusk progresses in order to not lose contact.
Many valuable contacts have failed of development on account of non-
observance of these rules.

5. The material condition indicates above average
deterioration, but the usual refit routine will restore most of the
material to normal conditions. The auxiliary generator will be
thoroughly cleaned and efforts will be made to eliminate the oil leak-
age. The present manganese bronze poppet roller cranks in all tubes
are being replaced by brass cranks. It is expected that all necessary
work will be accomplished within the regular refit period.

6. The Commanding Officer, Officers, and Crew are con-
gratulated for the damage inflicted on the enemy.

[SIGNATURE: J.B. GRIGGS]
J.B. GRIGGS.
SUBMARINE SQUADRON TWELVE

Care of Fleet Post Office,
San Francisco, California,
22 June 1944.

— page 98 —
[HANDWRITTEN: 716-316]
FE24-71/A16-3
Serial: 0669

UNITED STATES NAVY

[HANDWRITTEN: 7179]
12a/pr 8 01365 i
11 July 1944.

C-O-N-F-I-D-E-N-T-I-A-L

SECOND ENDORSEMENT to:
CO USS ASPRO Comf. Ltr.
A16-3 Serial 012 dated
16 June 1944. Report
of Third War Patrol.

From: Commander Task Force SEVENTY-ONE.
To: Commander in Chief, UNITED STATES FLEET.
Via: Commander SEVENTH FLEET.
Subject: U.S.S. ASPRO (SS309) - Report of Third War Patrol -
 Comments on.

1. The remarks of Commander Submarine Squadron TWELVE
are concurred in.

2. The Force Commander notes with pleasure the determ-
ination displayed by ASPRO to insure the sinking of ships damaged
on previous attacks.

3. This patrol is designated as "Successful" for
purpose of award of the Submarine Combat Insignia.

4. The Force Commander congratulates the Commanding
Officer, Officers, and Crew of ASPRO for the following damage
inflicted upon the enemy:

 SUNK
AK - Large (EU) 7500 Tons (Attack No. 2)
AK - Medium (EU) 4000 Tons (Attack No. 4)
 TOTAL 11500 Tons

5. Since the above damage was accomplished in areas
under the operational control of Commander Task Force SEVENTEEN,
he is requested to assume credit accordingly.

[SIGNATURE: P. F. Straub Jr.]
P. F. STRAUB, Jr.,
Flag Secretary.

[SIGNATURE: R. W. Christie]
R. W. CHRISTIE.

DISTRIBUTION:
Cominch (3) (Direct) ComSubs2ndFlt ORIGINAL COPY
Vico OpNav (2) (Direct) CTF-71 (4)
VicoOpNav Op-23c (1) CTF-72 (2)
ComlstFlt (1) CSS-12 (1)
Com2ndFlt (1) CSS-16 (1)
Com3rdFlt (1) DivComs Ron-12 (1)
Com7thFlt (2) DivComs Ron-16 (1)
ComSubslstFlt (4) S/M Skl. N.L.Conn. (2)
 Each S/M W.A. (1) - NOT TO BE
 TAKEN TO SEA - BURN.

— page 99 —
A16-3(F-3/roj)
Serial: [HANDWRITTEN: 01054]

UNITED STATES FLEET
COMMANDER SEVENTH FLEET

[STAMP: Reg. No. 10490]
[STAMP: R.S. No. 8 01365]

[STAMP: 30 JUL 1944]

C-O-N-F-I-D-E-N-T-I-A-L

THIRD ENDORSEMENT to:
CO USS ASPRO conf. ltr.
A16-3 Serial 012 dated
16 June 1944. Report
of Third War Patrol.

From: Commander Seventh Fleet.
To : Commander in Chief, United States Fleet.

Subject: U.S.S. ASPRO (SS309) - Report of Third
War Patrol.

1. Forwarded.

2. The Commanding Officer, Officers, and Men of
the U.S.S. ASPRO are congratulated for having conducted
a successful war patrol.

[HANDWRITTEN: 1-03998]

[SIGNATURE: H. W. Graf]
H. W. GRAF,
Chief of Staff.

Copy to:
CTF-71
ComSubRon-12
CO U.S.S. ASPRO

[HANDWRITTEN: X]

— page 101 —
[STAMP: 1ST COPY]

U.S.S. ASPRO (SS309)
Care of Fleet Post Office,
San Francisco, California,

18 August, 1944.

SS309
Serial 015
C-O-N-F-I-D-E-N-T-I-A-L [STAMP: DECLASSIFIED]

From: The Commanding Officer.
To : The Commander in Chief, U.S. Fleet.
Via : Official Channels.

Subject: U.S.S. ASPRO (SS309), Report of War Patrol
Number Four.

Enclosure: (A) Subject Report.
(B) Track Chart.

1. Enclosures (A) and (B), covering the fourth war
patrol of this vessel conducted in South China Sea, west of Luzon between
16-30 N and 18-30 N, during the period 9 July to 18 August, 1944, is
forwarded herewith.

[SIGNATURE: A. Stevenson]
A. STEVENSON.

DECLASSIFIED ART. 0445, OPNAVINST 5510.1C
BY [HANDWRITTEN: OP-09B9] DATE [HANDWRITTEN: 5/23/72]

[STAMP: DECLASSIFIED]

[HANDWRITTEN: 89753]

— page 102 —
C-O-N-F-I-D-E-N-T-I-A-L

(A) PROLOGUE

Arrived FREMANTLE, W.A. from Third War Patrol 16 June, 1944.
Commenced refit by Submarine Repair Unit, and Submarine Division
122 Relief Crew. Number 4 Main Ballast Tank was converted to
a fuel ballast tank. Refit completed 30 June, 1944. Conducted
training 5-7 July, 1944; fired two exercise torpedoes. Fueled
and provisioned 7-8 July, 1944. Departed for Fourth War Patrol
9 July, 1944.

On departure from FREMANTLE, W.A. two men were on the
sick list: BOZARTH, F.L.,jr., 372 09 38, Tlc., USN., sustained
a back injury the day before departure and with the medical
officers consent it was decided to take him as far as DARWIN
in case he should improve sufficiently to continue the patrol;
MATTINGLY, O.C., 337 48 54, MoMlc., USN., was suffering from
an abscessed tooth. The dental officer considered it possible
for MATTINGLY to make the patrol.

(B) NARRATIVE

All times zone (-8) HOW.

9 July, 1944
1333 Underway from alongside U.S.S. GRIFFIN, FREMANTLE, W.A.
for Fourth War Patrol. Joined U.S.S. RAY in the exercise area.
Conducted practice approaches; target HMAS DUBBO.
2040 Departed exercise area in company with U.S.S. RAY.

9-16 July, 1944
Enroute DARWIN, in company with U.S.S. RAY as far as the
EXMOUTH bombing lane. Conducted training enroute. Made daily
training dives, conducted tracking exercises, battle problems,
emergency drills, fired all guns.

10 July, 1944
1320 Sighted unidentified aircraft on southeasterly course,
distant seven miles.

11 July, 1944
2330 U.S.S. RAY departed.

12 July, 1944
1800 Sighted submarine, friendly. Exchanged calls and
information.
1900 Master gyro out of commission. Commenced steering by
auxiliary compass.

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2110 Master gyro back in commission.

13 July, 1944
1516 Sighted small frigate type ship on opposite course
distant approximately 8 miles. From information received
this contact was identified as the U.S.S. CORPUS CHRISTI.
2030 Sent ASPRO Serial One.

14 July, 1944
0835 Master gyro out of commission. Commenced steering by
auxiliary gyro.
We had been operating the gyro at a latitude sett-
ing of 50 degrees, due to inability to maintain the vacuum
in the rotors when set for higher speed running. Many
azimuths and constant checks with the auxiliary indicated
the gyro error had been small and constant. However, at this
time the gyro suddenly went out 14 degrees, but it was noted
that it had started to return to the true heading. Attempted
to determine the cause and remedy if possible.
1230 Sent ASPRO Serial two.

2110 Master gyro back in commission after renewal of one
badly worn rotor bearing. Continued to check heading every
five minutes with the auxiliary.

15 July, 1944
2006 Received ComTaskForce Seventy One message, giving
rendezvous information and informing us that a gyro man would
be at DARWIN to give assistance.

16 July, 1944
0005 SJ radar interference.
0140 Exchanged calls with friendly submarine using the
transmitter key on the SJ.
0528 Sighted escort HMAS M.L. 814. Exchanged calls.
0905 Moored starboard side to dock DARWIN. Received 21,775
gallons fuel oil, 600 gallons lub oil, topped off with battery
and fresh water and provisions.
Transferred BOZARTH, F.L.,jr., 372 09 38, Tlc., USN.,
to the U.S. Navy Section Base, "WALK" for treatment and furth-
transfer to the Relief Crew CSD-122.

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Medical and dental treatment was given three men.

Received SERIGHT, Eldon Lee, 690 00 70, MoMM2c., V-6,USNR.,
aboard for duty from the U.S. Navy Section Base "WALK".

1636 Underway from alongside, BOOM DOCK, DARWIN enroute patrol
area.

2106 Started calibrating magnetic compass.

2317 Completed calibration of magnetic compass. Went ahead
two engine speed, 14 1/2 knots.

17 July, 1944

0532 Made trim dive.

0548 Surfaced.

0710 SD contact 8 miles. Dove.

0735 Surfaced.

2000 Started passage into the BANDA sea via east of TIMOR.

18 July, 1944

1245 Sight contact on plane distant 9-10 miles. Dove.

1330 Surfaced.

1518 SD contact 16 miles, opened out to 21 miles.

2200 Started passage from the BANDA to the MOLUCCA sea via east
of SOELA ISLANDS.

19 July, 1944

0220 SJ contact 15,500 yards, 083 true. Stationed the radar
tracking party. Lost contact several times due to the extreme range.
We wanted to track outside of 17,000 yard range, however, a range
of 15,000 yards appeared to be the maximum tracking range. The
pips seemed unsteady even at this range. There were four or
five contacts very close together.

0259 Regained contact, 109 true distant 16,200 yards. Maintained
contact and continued tracking. Determined target group was on a
southeasterly course. Went ahead flank speed to gain position ahead.
The target group appeared to be headed for MANIPA STRAIT possibly
enroute AMBON.

0410 Reached position ahead of convoy, 15,000 yards range. Slowed
to eight knots. There was insufficient time to make a surface
attack. Decided a dawn attack was preferable anyway because of the
uncertainty of whether the contacts were worth torpedo expenditure.

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The characteristics of the radar pips indicated they were quite
small - possibly wooden barges.

0425 Detected radar interference on 358 megacycles on the
radar detector. There had also been a faint trace of interference
on the SJ.

0450 Sighted the target group. Four fairly good sized ships
were observed. Two were smoking quite heavily.

0510 Heard pinging in the direction of the convoy.

0511 Submerged, commenced approach.

0520 The convoy consisted of four medium sized marus with five
escorts. The marus were in line of bearing at fairly close
interval. All escorts were closing the convoy. Two of the
escorts finally took station ahead of each wing freighter. The
other three escorts were on each quarter and astern - they were
never observed closely. The two lead escorts were pinging. There
seemed to be considerable signalling and one escort had a flag
hoist. One of the pingers sent something that sounded like."BT
PIM".

All four marus were the conventional M F M type, estimated
5000 tons. One of the two escorts in the lead was a new trim
looking single stack escort, shaped like a destroyer but smaller.
The other escort looked like a converted yacht. This escort
had a small Japanese merchant flag on the side of the pilot house.

We were right on the track of the second maru from the left.
The convoy was zigging every five minutes. Continued approach on
the second maru from the left, but made ready all tubes.

0536 A zig to the left gave us a starboard angle on all marus.
Since the starboard wing ship was the closest, started approach
on this ship.

0542 An observation indicated a forty five degree zig to the
right. Shifted to the second maru. This zig was the extreme
right leg of their zig plan and their line of bearing formation
put them very nearly in column, however, the formation was
ragged. The left wing ship had very nearly a zero angle. The
yacht type escort was ahead of him and fairly close. The leading
starboard escort was overlapping the right hand ship.

0545-45 Started firing four bow tubes at the second maru from
the left in the formation; torpedo run 1800 yards, gyro 9 R,
55 degree port track, two degree spread.

0546-35 Shifted to the third maru from the left, who at this time
was astern and on the port quarter of the second maru. Fired
the remaining two bow tubes; torpedo run 1450 yards, gyro 13 R,
51 degree port track, two degree spread. Swung to the right to
bring the stern tubes to bear.

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0546-55 Heard torpedo explosion.
0547-05 Heard and saw two more hits in the first ship fired on.
          The hits completely obscured the target. The ship astern, the
          second ship fired on, had changed course toward and probably
          succeeded in avoiding the two torpedoes fired at him. Shifted
          to the right hand maru and observed the leading escort, neither
          had changed course.
0547-17 Started firing four Mark 18 torpedoes from the stern
          tubes; torpedo run 2300 yards, gyro angle 279, 101 degree
          port track, two degree spread.
0548    Went to 400 feet and rigged for depth charge. The destroyer
          type escort had not started to turn but uncertainty about the
          location of the Yacht type escort who should have been close (sound
          never did pick him up) and the fact all torpedoes had been
          expended was enough inducement to go deep.
0550-02 Torpedo explosion. Hit for the first torpedo from the
          stern tubes.
0550-29 Torpedo explosion. Hit for third torpedo.
0550-37 Torpedo explosion. Hit for fourth torpedo.
0551-20 Depth charge.
0551-25 Depth charge.
0551-45 Depth charge.
0554-55 Depth charge.
0555-15 Depth charge.
0556-10 Depth charge
0600-05 Depth charge.
0602-55 Depth charge.
0603-40 Depth charge.
          None of the charges were very close. Pinging continued but
          we were safe under a 12 degree temperature gradiant. Opened the
          range at two thirds speed.
0705    At periscope depth observed the Yacht type escort in the
          vicinity of the attack distant about five miles. Nothing else
          was in sight. The escort continued to ping. The two damaged
          ships must have sunk.
0853    Observed plane circling the vicinity of the escort.
0855    Lost contact with the pinging.
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1457 Surfaced. Resumed course for area.

1645 Received ComTask Force 71 dispatch modifying our operation
order.

1808 Stopped starboard shaft to examine main motors; difficulty
was experienced balancing the load between the two motors.

1834 Resumed speed on both shafts. Number 3 main motor was
sparking but not seriously. Continued to watch it closely intend-
ing to work on it the first time we were submerged for a long
enough period.

1910 Sent ASPRO Serial three.

2101 Received CTF 71 message modifying our operation order to
proceed directly to our patrol area.

2330 Stopped starboard shaft when number 3 main motor started
sparking badly. Preliminary examination indicated brush rigging
damaged. Decided to work on this motor the next day submerged.
Disconnected number 3 main motor electrically. This limited us
to 190 rpm on the starboard side, however, we could still make
about 17 1/2 knots.

20 July, 1944

0649 Submerged 4 miles north of TALIABOE ISLAND.

     Radar contact on land before submerging indicated the SJ
radar was not up to its usual performance. The maximum range
obtainable on high land was about 45,000 yards.

     Stopped starboard shaft to allow work to be started on
number 3 main motor. We were able to use the starboard shaft at
anytime, but we were handicapped in having a minimum speed
on that side of standard.

0953 Heard pinging bearing 240 true.

0956 Sighted black smoke on same bearing as pinging. Determin-
ed target group was following close to beach. Came to normal
approach course and started approach.

1022 Sighted the tops of the target.

1106 The target group consisted of a medium freighter, conventional
MFM type, estimated 4000 tons, and two escorts, one leading and
one astern. The leading escort was a little larger than a PC,
similar to a small CL. The leading escort pinged intermittently.
The target group was zigging every five minutes. We had reached
a position on the track of their base course.
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1124 Arrived in position for a down the throat shot on 10
    degree starboard track, at a range of 2400 yards approximately
    when at

1126-20 the target and escort were observed zigging right and now
    had a 35 degree port angle. Changed course twenty degrees left
    for a 50 port track for the bow tubes.

1127-23 Started firing four bow tubes at the freighter; torpedo
    run 1350 yards, gyro angle 20 R, 45 degree port track, two degree
    spread. When the check bearing was called the angle on the bow
    was estimated at 55 P - this was introduced into the TDC. Almost
    immediately it was realized the angle was nearer 70 P. A past
    analysis indicated the target was just completing the zig at the
    time of firing. The commanding officer unfortunately was mis-
    informed on the gyro angles. The gyro angles were called out as
    10 R shortly before the check bearing, but this was before we
    had steadied on the firing course. When the torpedo run was 1400
    yards and with the previous information on the gyros it was
    decided we had reached the best position.

1129-30 Raised periscope on bearing of target. The target was
    obscured by smoke or spray. Although no hits were heard or seen
    it was quite possible we damaged the target. Turned periscope
    approximately ten degrees to the left and picked up escort with a
    30 degree port angle and turning in our direction. Went to 450
    feet, fortunately we could still do this - we were less than two
    miles from the 50 meter curve.

1131-17 First charge at 375 feet followed closely by seven more
    in the next 23 seconds.

1132 Three more depth charges.

1137 Five more depth charges.

1141-30 Four more depth charges.

1147-20 Seven more depth charges.

1149-37 Single depth charge.

1150-35 Single depth charge.

1151-14 Single depth charge.

1151-50 Single depth charge.

    All the depth charges were close and right on top of us.
    They are the closest this ship has had yet but no damage was
    sustained. We were under a gradient at 450 feet and the escort
    pinged in vain.

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1215 At periscope depth. The escort who had been the trailing
escort was 4000 yards distant conducting a listening search.

This escort conducting the search looked like a mine layer.
It was difficult to estimate his tonnage and we had no pictures
like him. He was carrying cargo on deck. The escort pursued the
usual search tactics of stopping to listen occasionally - he never
approached closer than 4000 yards. He must have been around 500
tons.

Just the targets masts and stack could be seen. The escort
with the freighter could be seen much easier. It was difficult
to see them against the land background, and we never had but
the one observation of them.

1540 Escort finally departed area.

1744 Surfaced.

We plan to run submerged again tomorrow in order to complete
work on number 3 main motor. There is also the possibility the
convoy has anchored overnight and we may be able to intercept them.

21 July, 1944

0620 Submerged 6 miles north of LINGOLI. Stopped starboard shaft
to continue work on number 3 main motor.

1312 Work completed on number 3 main motor. All tests indicate
normal operation.

1735 Surfaced. Enroute patrol area at two engine speed.

The SJ radar was still not satisfactory. Efforts to locate
the difficulty had been unsuccessful.

22 July, 1944

0700 Commenced passage from the MOLUCCA SEA into the CELEBES SEA
via BANKA PASS.

Sighted a small open boat in the pass and three small sail
boats (triangular sails) in the CELEBES SEA near the pass. Avoided.

1025 Made trim dive.

1039 Surfaced.

1423 Lat. 2-20 N Long. 124-42 E O.O.D. sighted a torpedo wake
fifty degrees relative. Changed course to the right and went
ahead flank. Two wakes were sighted, one passed to port and the
other to starboard. The torpedoes must have been fired at extreme
range. The O.O.D., Lieutenant (jg) D.W. SIMPSON, USNR., acted
promptly and correctly. We had been following a zig plan which

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called for a change of course every five minutes. We had just
completed a zig when the wakes were sighted.

23 July, 1944
0755 Submerged fifty miles from SIBUTU PASS.
1829 Surfaced.

The sky was overcast and we did not have a fix. It was a
dark night but decided to go through pass if our radar was able to
pick up the low islands on each side.

1947 Radar contact 1200 yards broad on port bow. Contact drew
aft and closed to 850 yards. Sighted what was believed to be
small boat. Avoided.

2117 Sighted land dead ahead; no radar contact on land on this
bearing.

2127 Reversed course.

2141 Decided land must be island on left of pass. Changed course
in another attempt. The visibility had improved some but it was
still quite dark.

2210 Sighted several small islands or peaks on either bow.
Reversed course and decided not to attempt passage until we had
determined where we were. We strongly suspected that we were
seeing the peaks on TAWI TAWI and we were northeast of the pass.

24 July, 1944
0548 Submerged. The peaks on TAWI TAWI were visible and we were
8 miles from ALNUK MANKA ISLAND.

1847 Surfaced. Commenced transit of SIBUTU PASS.

2100 Completed transit of SIBUTU PASS.

25 July, 1944
0028 Passed between PEARL BANK and LAPARAN ISLAND.

1548 Made trim dive.

1558 Surfaced.

26 July, 1944
0008 Made sight and radar contact on small vessel, either
patrol boat or sampan, distant 2000 yards. Avoided. Radar lost
contact at 3800 yards. We were 10 miles west of NASO POINT.

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0916 Sighted APO ISLAND light house, distant 16 miles.

1001 SD contact 12 miles, closed to 9 miles.

1003 Sighted three planes, large bombers on port bow. Dove.
We were 6 miles from APO ISLAND. Decided to remain submerged
and complete transit of MINDORA STRAIT during darkness.

1510 Surfaced in heavy rain squall. Continued transit of MINDORA
STRAIT.

27 July, 1944

1045 Sighted friendly submarine, distant about 3 miles. Sent out
call using SJ transmitter key. They sent "R" for our call but we
were unable to obtain their call. Continued to close submarine.

1105 Exchanged information with friendly sub via visual commun-
ications.

1120 Set course for area.

1400 Arrived in area. Commenced surface patrol.

1610 Made trim dive.

1620 Surfaced.

28 July, 1944

0513 Submerged 6 miles from DILI POINT, on the island of LUZON.

0547 Heard distant echo ranging. Sighted small sail sampan -
close to the beach.

0605 Sighted mast in direction of pinging. Contact was patrol
vessel conducting search three to four miles off coast. The patrol
vessel was a trim looking craft, smaller than a CHIDORI, with a
single upright stack, gun forward and gun aft, tripod foremast,
deck house amidships, and could have
been a CM, however, we had no pictures that looked like him. We
had several good looks at him during the day since on several
occasions he approached to within 3500 yards.

0915 Sighted float plane proceeding down the coast.

0925 Sighted a ship in close to the beach. Started closing.

On several occasions flag hoist signals were observed on
the patrol vessel.

1208 Went deep when the patrol vessel headed for us and indicated
he had sound contact.

1300 At periscope depth. The patrol vessel had departed. Pinging
could no longer be heard.

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1310 Sighted two bombers headed down the coast.

By this time we had determined the exact position of the
anchored ship. (Lat. 17-31.2 N Long. 119-22.7 E). The ship was
anchored six hundred yards from the beach. A small tug was anchored
close by, and a sunken ship was also seen (Lat. 17-30.4 N Long.
119-23.5 E).

We selected a position where we could approach within 2000
yards of the ship and still be close to deep water. Commenced
approach.

The target resembled very closely the URAL MARU, (page 32
ONI 208 J, revised).

It was flying a Japanese man-of-war flag, and had her
boilers lit off - a light smoke haze could be seen.

1525-48 Commenced firing three bow tubes at anchored target; torpedo
run 2200 yards, zero gyro angle, 40 degree starboard track, 1/2
degree spread.

1527-26 Heard first torpedo explosion.

1527-28 Heard and saw second torpedo hit.

1527-51 Heard and saw third torpedo hit.

Commenced retirement at periscope depth.

1529 Observed damaged ship smoking heavily amidships. Sound
reported screw noises in the direction of the target. It was
possible the ship managed to back down and beach herself. Flashes
from the fantail were observed that could have been gun flashes.
Boats were being lowered. The tug was smoking and evidently trying
to get underway.

1547-40 Heard several explosions at this time. An observation
revealed flames had broken out amidships.

1551 Tug finally succeeded in getting underway. He headed in
our direction several times but finally departed on a northerly course.

1555 The flames were getting much worse. The ship had taken a
slight list to starboard and had settled.

1630 The fires were definitely out of control by this time. The
ship was a mass of flames and fires could be seen at the water line.
Continued to hear minor explosions and air noises. Allowed all
hands to observe the burning ship.

1630-1810 Continued opening out from the coast and observing the
burning ship.

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1810 Observed several bursts of flame believed to be explosions
     on the ship. The visibility shortly thereafter started to decrease
     and at

1818 The target and land were no longer visible. Came to 45
     feet but was still unable to see the target.

1853 Surfaced.

2334 Made sound contact followed immediately by sight contact
     of small vessel bearing 340 relative. Turned away and started
     to speed up. SJ contact was made at 4000 yards. The target
     had a small angle and was closing the range. Then the range had
     closed to 2650 yards at

2338 Dove and went to deep submergence. Target passed down port
     side, we were evidently never sighted. From the characteristic of
     the pip on the SJ the contact must have been a small patrol craft.
     We were slow in accelerating and the decision was made to dive. It
     is now realized that we could have out run this contact.

29 July, 1944

0037 Surfaced. No contacts on SJ.

0504 Submerged 5 miles bearing 235° true from CAPE BOJEADOR
     light to conduct submerged patrol.

     Sighted a total of nine planes during the day, all were
     flying low and paralleling the coast.

0859 Sighted masts of two ships bearing 010 true. Changed course
     to head for them. These contacts were soon identified as two
     motor sampans lying to.

0950 Sighted masts of at least ten ships. Commenced approach.

1102 Identified contacts as convoy of sampans following close
     to coast making about four knots. They were all similar in
     appearance; two high masts, deck house aft, tonnage estimated
     from 50 to 150 tons. There were twenty two of them.

1110 Heard echo ranging.

1113 Sighted patrol vessel in direction of pinging. This contact
     was later identified as the same patrol vessel we encountered
     yesterday. Decided to make approach on him.

1132 Then at a range of 2800 yards with a 60 port angle, the
     target suddenly turned away and opened the range rapidly. The
     target, just before this maneuver, had (according to our sound-
     man) given every indication that he had a contact on us.

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1415 The sampan fleet had reversed course and most of them had
sailed up. The wind and sea were picking up and the visibility
had decreased.

1857 Surfaced.

2330 Master gyro out of commission. Commenced steering by
magnetic. Started auxiliary gyro.

30 July, 1944.

0523 Submerged. Will conduct submerged patrol in order to
make repairs to master gyro.

1515 Master gyro back in commission.

1552 Surfaced.

31 July, 1944 - 3 August, 1944

Conducted surface patrol on station. Made daily trim dives.

4 August, 1944

0519 Submerged 4 miles from PINGET ISLAND.

0620 Sighted plane headed down the coast.

1035 Sighted ship we hit on the 28th or another anchored in
the same position, continued to close.

1525 Ship was definitely identified as the one we hit. He seemed
high out of the water - the top of his rudder could be seen. Both
masts, stack, and even ventilators looked unchanged in appearance.
He was completely rust colored from the fires. At a range of 9000
yards he didn't appear to be damaged very much.

1603 Sighted two planes (Mary and Betty), one headed up the coast
and one down the coast.

1800 Approached to within 2800 yards of the damaged ship. Took
pictures.

The target was definitely hard aground, down by the bow and
listed slightly to starboard. Two holes could be seen in his
side at the water line, one under the stack and one at the bow. He
appeared to be completely gutted by the fires. It was decided not
to fire any more torpedoes at this time. We only have seven torpedoes
and fourteen days on station. This ship will be there for sometime.
It is doubtful whether more torpedo hits would accomplish a cleaner
job of destruction.

1914 Surfaced.

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5 August, 1944

0529 Submerged.

0813 Sighted plane (PETE) distant approximately three miles.

0833 Sighted ship in close to the beach, smoking heavily. Came
to normal approach course. The visibility was very poor.

0850 Sighted second ship, just astern of the first. Both ships
were at the limit of visibility, approximately five miles.
Continued to close at high speed at 85 feet, but it was doubtful
whether we would be able to close to firing range.

0929 Came up to periscope depth and observed three large sampans
with a small port angle distant about 5000 yards. We had lost
bearing on the freighter contacts and the range had opened.
Discontinued approach.

0952 Observed two more sampans on same course as first three
observed (course - 150 true.).

1012 Sampans passed down port side about 500 yards. Observed
another sampan on starboard quarter.

1036 Started to open out from the coast.

1112 Surfaced. Will attempt to gain position ahead of freighter
contacts.

1116 Sighted BETTY plane at an estimated range of 4 miles headed
down the coast. SD contacts two miles. Dove. We were evidently
not sighted. Stern plane motor failed to operate on the dive.

1225 Stern planes back in commission.

1230 Surfaced. Went ahead flank speed on three engines. We
planned to be ahead of the contacts in the vicinity of CAPE BOJEADOR
at dark.

1636 Sighted MAVIS plane distant approximately ten miles headed
down the coast.

1637 Submerged when plane headed for us. Continued to close
CAPE BOJEADOR at high speed submerged. Estimated we should
definitely be in sight contact by sunset if they didn't anchor for
the night.

1850 Surfaced. Continued search.

2030 Opened out from coast. Will conduct submerged patrol
tomorrow in the vicinity of CAPE BOJEADOR.

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6 August, 1944

0323 Heard pinging bearing 350 true.
0333 Sighted dark object in the direction of the pinging. Visibil-
    ity was excellent. We did not have radar contact.

    Determined contact was a patrol craft conducting a sound
    search at 14-15 knots on course approximately 180 true. Maintainod
    our relative position at an estimated 12,000-15,000 yards ahead
    to be in position for a submergod attack if target turned out to be
    worthy of torpedoes.

0509 Submergod.

0540 The patrol vessel had a single stack, gun forward and aft,
    estimated tonnage 400-500 tons - similar to types previously
    encountered on this patrol.

0610 Lost contact with pinging and sight contact with target.

0703 Sighted several sampans in close to the beach.

0708 Sighted plane (unidentified) headed down the coast.

0901 Sighted two planes distant five miles, bearing 225 true
    circling.

0923 Sighted the two ship contacts we chased yesterday. Started
    approach. Sighted six planes in formation on westerly course
    distant about six miles.

    The leading ship was a M F M well deck freighter of 3000-
    4000 tons. The second ship was a small coastal passenger freighter
    of about 1500 tons similar to TATIBAN type, page 27 ONI 208 J
    revised.

1016-10 Started firing three bow tubes at the leading freighter;
    torpedo run 1700 yards, gyro angle 1 degree left, 90 port track,
    three degree spread.

    The targets were skirting the ten fathom curve. We fired
    from a position just inside the twenty fathom curve. The torpedoes
    were set for a depth of six feet. Just before firing the top of
    the target's rudder could be seen and it was realized then that
    the freighter was in the light condition.

1017 Observed the torpedoes running; one was leaving a trail of
    smoke. Lowered periscope and started turn to open out. We
    not in position for an attack on the second target.

1017-40 Raised periscope and observed smoke at the water line
    amidships. The torpedoes should have been hitting, but no hits
    were heard or seen. It was feared the torpedoes had run under.

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1019 Observed target turning toward us. Went to 100 feet to
avoid about six sampans close aboard.

1021 One torpedo exploded, probably when it hit the beach.
Heard by sound but not heard through hull.

1040 Heard echo ranging bearing 000 true.

1045 At periscope depth observed target still underway but
definitely listed to port. The target had about a 15 degree
port list. One torpedo hit should have sunk this ship. There
was a possibility of an exploder failure.

1108 Went to 150 feet when plane headed in our direction,
distant approximately 3 miles. We could still hear pinging but
nothing could be seen on that bearing.

1113 Periscope depth.

1120 Sighted patrol vessel in direction of pinging and
closing the freighter we just attacked. He was signalling by
searchlight. The second freighter had passed the freighter
attacked. Observed smoke bearing 350 true.

1132 Sighted tops of at least ten ships. Came to normal
approach course and ran at 7 1/2 knots at 85 feet.

1221 Identified contact as large convoy of at least 17 vessels.
They had a large port angle. Undoubtedly they were giving the
location of the recent attack a wide berth. Several tankers and
large freighters were observed. There was a M.VIS plane circling
the convoy. A positively identified T.M.T.K.E class destroyer was
about 7000 yards distant conducting an echo ranging search. The
patrol vessel that had closed the freighter we attacked was
conducting a search close to the beach.

Continued to close the convoy at periscope depth. Several
times during the next hour and a half the destroyer gave indica-
tions of having contact on us. Conducted several approaches on
him during this time but was unable to obtain a favorable firing
position.

1426 The range to the nearest ship of the convoy had closed to
about 8000 yards but we were abaft their beam on a parallel
course and the range had started to open. Another T.M.T.K.E
destroyer was observed maintaining a close in patrol. There
seemed to be about as many escorts as ships. Discontinued approach.

1725 Smoke of convoy was still visible. Three planes were circling
convoy, two were M.VIS planes and one was a fighter type. We
could still hear echo ranging. The two M.VIS planes were still
visible until it became too dark to see them.

1910 Surfaced. Went ahead flank speed on two engines. To plan

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C-O-N-F-I-D-E-N-T-I-A-L

to make and around staying fairly close to the coast to take
advantage of the land background, and remain outside of 20,000
yards of convoy in order to avoid outer screen of escorts.

1915 Started transmitting SPRO Serial Four.

2035 Made radar contact, 13,950 yards in the direction of land.
This was a ship contact; the visibility was too poor to identify
contact. Decided to avoid and continue around on convoy.
Went ahead flank speed on three engines.

2130 Attempted to raise area boats by voice radio, but without
success.

2235 Heard echo ranging.

2241 Made sight contact with several ships of convoy, estimated
range of 21,000 yards. We were still unable to pick up convoy
by radar.

2320 Heard echo ranging bearing 020 relative. Made sight contact
on this bearing with escort at an estimated range of 12,000
yards. He was evidently at the outer limit of his search and had
started back in the direction of the convoy.

2326 Made momentary radar contact with one of the ships of the
convoy at 17,500 yards. This apparently is the limiting range
of our SJ. We were forced to turn away to run around escort.

2342 Heard echo ranging and made sight contact with escort on
starboard beam. Picked up possible radar interference on 365 megs.

2351 Escort evidently detected us because he headed in our
direction. Turned away and went ahead flank speed on four engines.
The range remained about the same, 12,000-14,000 yards. However,
we never had radar contact. He lost us against the land back-
ground and we managed to work around him.

7 August, 1944

0103 Suddenly picked up strong radar interference and made
sight contact with ship believed to be friendly submarine. Avoided.

0108 Lost radar interference and sight contact. Submarine must
have submerged.

0110 Received message by voice from R.TON that we were four
miles astern of him and that his radar was temporarily out of
commission.

0130 Made sight contact and SJ contact at 7500 yards. This
was probably the R.TON again.

0140 Made sight contact with several ships of convoy.

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C-O-N-F-I-D-E-N-T-I-A-L
0147 Sighted plane over convoy.

0158 We were 18,000 - 20,000 yards ahead of the convoy on our
best estimate of the target's track. The closest escort was about
12,000 yards distant patrolling ahead of the convoy. We planned
to close the convoy until within radar range and were forced to
dive because of visibility conditions.

0201 Dove when plane suddenly closed to 6000 yards by SJ. The
range to the convoy was estimated at 17,000 yards.

0241 Observed convoy zig toward us. Twelve large marus were
counted, there were possibly more. The closest escort when we
dove was still the nearest ship.

0246 Escort started pinging in our direction and headed for us.

0248 Went to deep submergence when the range closed to 2000 yards
and escort had a zero angle.

0304 At periscope depth. The visibility was not as good as it
had been. The convoy could be easily seen but it was most difficult
to get ranges. In the first group of about six ships were three
to four large tankers; the second group consisted of six to seven
large and medium sized freighters. The escort that forced us
down was still the closest ship. Several other escorts were
observed closer to the convoy.

0314 Escort started closing us with a 30 degree starboard angle
pinging in our direction on short scale. Started approach on
escort; we were 900 yards off his track and in an ideal position.
A turn count indicated his speed was about 13 knots. As he
approached it became more and more apparent that he was not a
destroyer, but one of the Nip's conventional type single stack
escorts of 400-500 tons. Decided to save my last four torpedoes
for the convoy.

0318 At a range of 850 yards with a large starboard angle the
escort started turning toward us, and sound reported target
starting to speed up. Went to 400 feet. Came to convoy's base
course. A set up had been obtained on one of the ships of the
convoy before going down. Sound bearings were obtained on this
ships screws during period at deep submergence.

The temperature gradient for the second time was effective
in causing the pinging escort to lose contact.

0332 Started for periscope depth.

0340 At periscope depth. Observed the convoy astern, all with
large starboard angles. The second group of ships were bearing
170 degrees relative. There were six to seven ships over lapping.
Put a set up in the TDC for the closest ship, a large freighter,
which also was the center ship of the formation, 3200 yards.

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C-O-N-F-I-D-E-N-T-I-A-L

"It was realized that we were at the extreme
range for firing Mark 18 torpedoes, but it was now or never. We
were pretty certain of hits if the torpedoes would run that far.

0345-34 Started firing four torpedoes at the center ship of a group
of six or seven over lapping maru's; torpedo run 3500 yards, gyro
angle 19 right, 90 degree starboard track, two degree spread between
torpedoes.

0349-04 Sound reported torpedo explosion.

0349-24 Heard and saw second torpedo hit large freighter in
the center of the group of ships. There was a large volume of water
observed amidships, the ship sagged in the middle like its back was
broken and started to settle. The bow was seen to rise at an angle
of 30 degrees and the ship was seen no more. Dense black smoke
was observed for a short time at the sinking.

0350-09 Explosion, heard by sound and several people on board.

0351 One torpedo could still be heard running.

0352 Observed another ship of group smoking. This ship must
have been hit by the third torpedo. The escorts in the van were
observed reversing course.

0353-20 Heard two aircraft bombs. They seemed quite distant.

Continued to open out from convoy.

0425 Sound reported explosion on the bearing of the convoy.

1030 Conducted periscope depth patrol in vicinity of attack.

1310 Heard fourteen (14) distant depth charges.

1350 Sighted L.V.I.S plane distant about 8 miles circling.

1421 Sighted plane (unidentified) distant about 7 miles circling.

1515 Heard distant echo ranging bearing 060 true.

1700 Sighted mast of patrol boat in direction of pinging.

1715 The patrol vessel was echo ranging on short scale and
was receiving an echo - the effect being the same as a ship echo
ranging on a contact within a 1000 yards. This cannot be explained.
The range was 14,000 yards but he was closing with zero angle.

1719 Went to 400 feet and got under a layer.

Patrol vessel continued to close and passed us close aboard
and opened range on a course of approximately 250 true.

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C-O-N-F-I-D-E-N-T-I-A-L
1838 At periscope depth. Observed patrol vessel distant 12,000
yards still going away.

1911 Surfaced. Set course for MINDORO STRAIT.

2014 Made radar and sight contact, 6700 yards on patrol vessel.
Tracked target at 16 knots on course 170 true. This was probably
the same patrol vessel encountered earlier returning to MANILA.
Avoided.

2100 Sent ASPRO Serial FIVE.

8 August, 1944

1401 Dove on sight contact with L2VIS plane distant about 10 miles.

1427 Surfaced.

1535 Started passage of MINDORO STRAIT.

9 August, 1944

0110 Completed passage of MINDORO STRAIT.

0820 Sighted small sail sampan distant 3 miles. Avoided.

1537 Made trim dive.

1545 Surfaced.

2144 Started passage between LAPARAN ISLAND and PEARL BANK.

2215 Completed passage.

10 August, 1944

0117 Started transit of SIBUTU PASS.

0300 Completed transit of SIBUTU. Set course for MAKASSAR STRAIT.

1700 SD contact 10 miles. Dove.

1831 Surfaced.

1835 Started passage of MAKASSAR STRAIT.

11 August, 1944

0543 SJ radar interference followed by radar and sight contact
with friendly submarine, range 6250 yards. Attempted to exchange
recognition signals. He was trying to send
something but his signal was too weak to copy.

Sighted a total of seven sail sampans during the morning,
distant 6 to 10 miles.
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C-O-N-F-I-D-E-N-T-I-A-L

1217 SD radar contact 4 miles. Dove. When we passed 38 feet
     the plane strafed us.

1225 Plane could not be seen at periscope depth. The sky was
     perfectly clear and it is hard to understand how the plane got in .
     so close without being sighted. He may have made a power dive out
     of the sun. An intermittent SD watch failed to pick up the plane on
     the proceeding search, however, at four miles the plane made a
     very large pip on the SD screen. We were fortunate the plane did
     not have bombs.

1257 Surfaced: Found several battle scars on our periscope shears.
1310 Sighted small sail sampan. Avoided.

<u>12 August, 1944</u>

0608 Submerged 70 miles from LOMBOK PASS.
1846 Surfaced 26 miles from LOMBOK.
2030 Started transit of LOMBOK PASS.
2213 Completed transit of LOMBOK.

<u>13 August, 1944</u>

1224 Sighted friendly submarine on opposite course. Closed and
     exchanged information.

1400 Sent ASPRO serial six.

<u>15 August, 1944</u>

0030 Picked up strong SJ radar interference. Exchanged recognition
     signals and calls with friendly submarine.

0652 Sighted two patrol vessels off NORTHWEST CAPE. Exchanged
     calls and recognition signals.

1017 Moored starboard side to fuel barge EXMOUTH GULF. Commenced
     transferring 19,310 gallons of diesel oil to the barge.

1643 Underway from alongside fuel barge, enroute FREMANTLE, W.A.

<u>15-18 August, 1944</u>

     Enroute FREMANTLE, W.A. Conducted training and made daily
     training dives enroute.

<u>18 August, 1944</u>

0815 Moored Berth 4 FREMANTLE.

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C-O-N-F-I-D-E-N-T-I-A-L

(C) WEATHER

No unusual conditions were encountered. West of northern LUZON skies
were generally overcast, surface visibility good with occasional rain, sea
generally from the southwest condition one to three.

(D) TIDAL INFORMATION

Tides were as indicated on charts and in sailing directions for LOMBOK
and SIBUTU. Approaching SIBUTU from the east submerged a northerly set of
about 1.5 knots was encountered farther from SIBUTU than the Sailing Directions
and charts led us to believe.

A slight northerly set was encountered off the west coast of LUZON.

(E) NAVIGATIONAL AIDS

No navigational lights were sighted. The structural part of the light
at the river mouth at VIGAN, LUZON, is as shown on the chart, but it isn't
burning.

(F) SHIP CONTACTS (SEPARATE PAGES)

(G) AIRCRAFT CONTACTS (SEPARATE PAGES)

(H) ATTACK DATA (SEPARATE PAGES)

(I) MINES - No mines were encountered.

- 22 -

— page 124 —
(F) SHIP CONTACTS

No. | Time | Date | Lat. | Long. | Types | Initial Range | Est. Course & Speed | How Contacted | Remarks
---|---|---|---|---|---|---|---|---|---
1. | 0220 | 19 July | 2-07S | 120-37E | Convoy - 4 med- | 15,500 yds | 145° T | SJ Radar | Torpedo Attack # 1,2,3.
| | | | | | ium AK's & 5 | | 8 knots | |
| | | | | | escorts. | | | |
2. | 0953 | 20 July | 1-34 S | Convoy - 1 med- | 12,000 yds | 115° T | Sound | Torpedo Attack #4.
| | | | | 120-51E | ium AK & 2 | | 7.5 knots. | |
| | | | | | escorts. | | | |
3. | 0850 | 22 July | 2-00 N | 3 Sampans | 7 miles | 160° T | Lookout |
| | | | | 120-30 E | | | 2 knots | Various | |
4. | 1015 | 22 July | 2-02 N | Unidentified | 1050 yds | | Lookout | Apparently small boat
| | | | | 120-17 E | | | | | lying to.
5. | 1947 | 23 July | 2-04 N | Small Unidentified | 3000 yds | | Lookout | Appeared to be small fish-
| | | | | 120-21 E | | | | | ing or patrol boat. Lying to.
6. | 0008 | 26 July | 1-45 N | Uncertain | 12,000 to | | Sound |
| | | | | 120-21 E | (Small Patrol) | 14,000 yds | | |
7. | 0547 | 26 July | 1-42 N | Naval Transport | 1000 yds | Undetermined | Sound | May have been same as #6.
| | | | | 120-21 E | | | | |
8. | 0925 | 26 July | 1-36 N | Unknown (Small) | 3400 yds | Southerly | Periscope |
| | | | | 120-21 E | | | 2 knots | Various | |
9. | 2334 | 28 July | 1-41 N | 21 Sampans | 8000 yds | Southerly | Periscope |
| | | | | 120-36 E | | | 2 knots | Various | |
10. | 0859 | 29 July | 1-34 N | Same ship as #7 | 12,000 yds | Various | Periscope |
| | | | | 120-30 E | | | | |
11. | 1110 | 29 July | 1-23 N | 2 small AK's | 12,000 yds | 030° T | Periscope |
| | | | | 120-04 E | | | 8 knots | Various | |
12. | 0833 | 29 July | 1-05 N | Numerous Sampans | Various | Various | Sound |
| | | | | 120-20 N | | | | |
13. | 0929 | 5 August | 1-19 N | Petrol Vessel | 12,000 yds | Southerly | Sound Heard |
| | | | | 120-12 E | | | | |
14. | 0333 | 6 August | 1-33 N | Petrol Vessel | 12,000 yds | Southerly | Sound Heard | Angling
| | | | | 120-21 E | | | | |

— page 125 —
(F) SHIP CONTACTS
No. | Time | Date | Lat. | Long. | Type(s) | Range | Initial | Est. Course | & Speed | How Contacted | Remarks
15. | 0703 | 6 August | 18-15 N | 120-24 E | Many Sampans | Various | | | | Periscope |
16. | 0923 | 6 August | 18-19 N | 120-26 E | 2 small AK's | 12,000 yds | | | | Periscope | Same as #12.
17. | 1120 | 6 August | 18-19 N | 120-26 E | Escort | 10,000 | | | | Periscope | Torpedo Attack #6.
18. | 1132 | 6 August | 18-19 N | 120-26 E | Large convoy of | 20,000 yds | | Southerly | 10 knots | Periscope | Similar to #7.
| | | | | | large AG's and AK's | | | | | |
19. | 2035 | 6 August | 17-41 N | 119-27 E | Many Escorts | 13,950 | | Southerly | 8 knots | Radar |
| | | | | | Unknown | | | | | |
20. | 1515 | 7 August | 16-29 N | 119-24 E | Patrol Boat | 12,000 yds | | Southwesterly | 8 knots | Periscope |
21. | 2014 | 7 August | 16-24 N | 119-24 E | Escort | 6700 yds | | 300°T | 10 knots | Sound Heard Ping |
22. | 0820 | 9 August | 9-56 N | 121-42 E | Sailboat | 8 miles | | Unknown | 15 knots | Lookout |
23. | [HANDWRITTEN: 1-15] | 11 Aug. | [HANDWRITTEN: 118-20 N] | [HANDWRITTEN: 116-10 E] | 7 Sailboats | Various | | Unknown | | Lookout |
24. | 1310 | 11 Aug. | [HANDWRITTEN: 118-20 N] | [HANDWRITTEN: 116-10 E] | Sailboat | 6 miles | | 030°T | 2 knots | Lookout |

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C-O-N-F-I-D-E-N-T-I-A-L
(G) AIRCRAFT CONTACTS

CONTACT NUMBER           8       9       10      11      12      13      14

Date                     7-28    7-29    7-29    7-29    7-29    7-29    8-4
S
U Time (zone)(-8)        1310    0746    0326    0928    1342    1425    0620
B Position: Lat.         17-34N  13-20N  18-20N  18-13N  18-16N  18-16N  17-35N
M Long.                  120-19E 120-23E 120-24E 120-23E 120-21E 120-20E 120-15E
A
R Speed                  2       2       2       2       2       2       2
I
N Course                 030     075     180     010     180     000     000
E
Trim                     Per     Per     Per     Per     Per     Per     Per
Minutes Since Last
SD Radar Search          -       -       -       -       -       -       -

Number                   2       1       1       2       2       3       1
A Type                   Betty   Betty   Betty   Nate    Nate    Nate    Betty
I
R Probable Mission       Trans   Trans   Trans   Trans   Trans   Trans   Trans
C
R How Contacted          Per     Per     Per     Per     Per     Per     Per
A
F Initial Range          6 mi    8 mi    5 mi    10 mi   2 mi    10 mi   4 mi
T
Elevation Angle          2       1       1       1       2       1       3
Range & Relative
Bearing of Plane
When it Detected
Submarine                ND      ND      ND      ND      ND      ND      ND
Sea: (State (Beau-
fort)                    3       3       3       3       3       3       3
C (Direction(Rel)        140     175     200     200     200     200     230
O
N Visibility(Miles)      15      20      15      15      20      20      7
D (Height in
I Clouds: ( ft.          7000    3000    6000    6000    6000    6000    7500
T (Percent
I Overcast               40      65      50      60      80      60      90
O
N (Bearing(Rel)
S Moon: (Angle
(Percent
Illum                    Daylight

— page 128 —
C-O-N-F-I-D-E-N-T-I-A-L
(G) AIRCRAFT CONTACTS

CONTACT NUMBER | 15 | 16 | 17 | 18 | 19 | 20 | 21
---|---|---|---|---|---|---|---
S Date | 8-4 | 8-4 | 8-5 | 8-5 | 8-5 | 8-6 | 8-6
U | | | | | | |
B Time (zone) (-8) | 1602 | 1604 | 0313 | 1114 | 1636 | 0708 | 0901
M Position: Lat. | 17-30N | 17-30N | 17-03N | 17-10N | 18-05N | 18-16N | 18-19N
A Long. | 120-20E | 120-20E | 120-14E | 120-20E | 120-10E | 120-24E | 120-29E
R | | | | | | |
I Speed | 2 | 2 | 2 | 10 | 14 | 2 | 2
N | | | | | | |
E Course | 150 | 150 | 200 | 340 | 038 | 045 | 045
Trim | Per | Per | Per | Surf | Surf | Per | Per
Minutes Since Last | | | | | | |
SD Radar Search | - | - | - | 0 | 0.5 | - | -
Number | 1 | 1 | 1 | 1 | 1 | 1 | 2
A | | | | | | |
I Type | Mary | Betty | Pete | Betty | Mavis | Unk | Unk
R | | | | | | |
C Probable Mission | Trans | Trans | Trans | Trans | Pat | Unk | Pat
R | | | | | | |
A How Contacted | Per | Per | Per | SD | Lookout | Per | Per
F | | | | | | |
T Initial Range | 4 mi | 4 mi | 5 mi | 2 mi | 8 mi | 5 mi | 8 mi
Elevation Angle | 3 | 3 | 1 | - | 1 | 2 | 1
Range & Relative | | | | | | |
Bearing of Plane | | | | | | |
Then it Detected | | | | | | |
Submarine | ND | ND | ND | ND | ND | ND | ND
C (State(Beau- | | | | | | |
O Sea: fort) | 3 | 3 | 3 | 3 | 2 | 1 | 1
N Direction(Rel) | 230 | 230 | 190 | 210 | 220 | 200 | 200
D | | | | | | |
I Visibility(Miles) | 7 | 7 | 3 | 12 | 20 | 30 | 30
T (Height in | | | | | | |
I Clouds: ft) | 6000 | 600 | 7000 | 6000 | 6000 | 10000 | 10000
O (Percent | | | | | | |
N Overcast) | 90 | 90 | 100 | 100 | 100 | 70 | 70
S | | | | | | |
(Bearing(Rel) | | | | | | |
Moon:(Angle | | | | | | |
(Percent | | | | | | |
Illum. Daylight | | | | | | |
Type of S/M Camouflage on this patrol Haze Grey.

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C-O-N-F-I-D-E-N-T-I-A-L
(G) AIRCRAFT CONTACTS

CONTACT NUMBER 29

Date 8-11
S Time (zone) (-8) 1217
U
B
M Position: Lat. 3-13 S
A Long. 113-28 E
R
I Speed 17
N
E Course 180

Trim Surf.
Minutes Since Last
SD Radar Search 0

Number Unk
A Type Unk
I
R Probable Mission H
C
R How Contacted SD
A
F Initial Range 4 mi.
T
Elevation Angle Unk.

Range & Relative
Bearing of Plane
When it Detected
Submarine UNK

C Sea: (State(Beau 3
O (Direction(Rel) 140
N
D Visibility(miles) 30
I (Height in
T Clouds: ft.) 15000
I (Percent
O Overcast 15
N (Bearing(Rel)
S Moon:(Angle
(Percent
Illum Daylight

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C-O-N-F-I-D-E-N-T-I-A-L
(H) ATTACK DATA
U.S.S. ASPRO (SS309) TORPEDO ATTACK NO. 1,2,3 PATROL #4.
TIME: 0545 (H) DATE 19 July, 1944 Lat. 2-20 S Long.126-37E

DESCRIPTION: Convoy of four medium maru's with five escorts.
Contact was made by SJ Radar at 15,000 yards. Position
ahead of the convoy was reached for a dawn periscope
attack. Visibility excellent.

SHIPS DAMAGED OR One M F M Maru (5000 tons)
PROBABLY SUNK: One M F M Maru (5000 tons)

Damage Determined by: Observed two hits in first maru fired on;
heard one additional timed hit in maru of first attack;
heard three timed No. 18 hits in maru of attack No. 3.

At periscope depth one hour and ten minutes after attack
observed one escort and plane at scene of attack. The
damaged ships were not in sight. It is, therefore, assumed
they must have sunk.

TARGET DRIFT: 9 ft. COURSE: 165°T. SPEED 8 RANGE 1800 (attack #1)
1450 (attack #2)
2300 (attack #3)

OWN SHIP DATA
SPEED 3 knots COURSE - 280°T (attack #1,2) DEPTH 60 ft. ANGLE - ZERO
325°T (attack #3)

FIRE CONTROL AND TORPEDO DATA
TYPE ATTACK: Target group was tracked by radar during an end
around to gain position ahead. Dove ahead of convoy and
made dawn periscope attack.

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C-O-N-F-I-D-E-N-T-I-A-L
(H) ATTACK DATA (continued)

                                        TORPEDO ATTACK #1
                                        1       2       3       4
Tubes Fired                             1       2       3       4
Track angle                             55P     54P     52P     59P
Gyro angle                              9 R     10 R    12 R    5 R
Depth Set                               6       6       6       6
Hit or Miss                             Hit     Hit     Miss    Hit
Erratic                                 No      No      No      No
Mark Torpedo                            23-0    23-0    23-0    23-0
Serial No.                              49348   49344   61321   49406
Mark Exploder                           6-5     6-5     6-5     6-5
Serial No.                              12659   7909    17336   17349
Mark Warhead                            16-1(Tpx)16-1   16-1    16-1
                                                (Tpx)   (Tpx)   (Tpx)
Serial No.                              12951   2923    17550   17176
Firing Interval                         0       9       9       11
Type Spread                             1 L     1 R     3 R     3 L
Sea Condition                           Calm - - - - - -
Overhaul Activity                       S/M Repair Unit, Navy No. 137
Remarks:                                None

                                        TORPEDO ATTACK NO. 2
                                        5       6
Tubes Fired                             5       6
Track angle                             51 P    50 P
Gyro angle                              13 R    14 R
Depth Set                               6       6
Hit or Miss                             Miss    Miss
Erratic                                 No      No
Mark Torpedo                            23-0    23-0
Serial No.                              49171   49450
Mark Exploder                           6-5     6-5
Serial No.                              25214   7941
Mark Warhead                            16-1(TPX)16-1(TPX)
Serial No.                              13030   12735
Firing Interval                         0       9
Type Spread                             1 L     1 R
Sea Conditions                          Calm - - - - -
Overhaul Activity                       S/M Repair Unit, Navy No. 137
Remarks                                 None

                                        TORPEDO ATTACK NO. 3
                                        7       8       9       10
Tubes Fired                             7       8       9       10
Track angle                             101 P   101 P   103 P   109 P
Gyro angle                              99 R    99 R    98 R    91 R
Depth Set                               6       6       6       6
Hit or Miss                             Hit     Hit     Hit     Miss
Erratic                                 No      No      No      No
Mark Torpedo                            18-0    18-0    13-0    13-0
Serial No.                              53723   54127   53897   53703
Mark Exploder                           4-7     4-7     4-7     4-7
Serial No.                              16373   16178   16885   16678
Mark Warhead                            18-0    18-0    18-0    13-0
Serial No.                              446     869     320     926
Firing Interval                         0       10      10      10
Type Spread                             1 L     1 R     3 R     3 L
Sea Condition                           Calm - - - - -
Overhaul Activity                       S/M Repair Unit, Navy No. 137
                                        - 31 -

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C-O-N-F-I-D-E-N-T-I-A-L
(H) ATTACK DATA

U.S.S. ASPRO (SS309) TORPEDO ATTACK NO. 5 PATROL NO.4
TIME: 1525 (H) DATE: 28 July, 1944 LAT.17-33N LONG.120-21E

TARGET DATA-DAMAGE INFLICTED

DESCRIPTION: Anchored ship, flying a Jap man-of-war flag, similar
to URAL MARU (Page 32 ONI 208 J, revised), possibly being
used as a naval transport.

A patrol vessel conducted an anti-submarine patrol off
anchored ship for a period of five or six hours prior to
the attack.

SHIP DAMAGED OR One M F A maru (similar to URAL MARU - 6,374 tons)
PROBABLY SUNK
(Note: Ship beached)

DAMAGE DETERMINED BY: Observed two hits and heard one additional
timed hit. Heard explosions on the sound gear and
observed fires raging, out of control, for a period of
two hours and forty-five minutes until the ship was lost
sight of due to visibility conditions.

Seven days later observed ship at a range of 2200 yards.
The ship had a slight starboard list, down by the bow, and
appeared to be completely gutted by the fires. Two holes
were observed at the water line - one under the stack and
one under the foremast. There was no signs of life on
board.

The previously reported anchored position of the ship
was close to the beach; however, there seemed little doubt
that the ship was now hard aground. The destruction of
this ship is as complete as might be hoped for from an
additional expenditure of torpedoes.

TARGET DR.FT 12 ft. HEADING 197°T SPEED 0 RANGE 2200 yds.

OWN SHIP DATA

SPEED: 2.5 knots COURSE 057°T DEPTH 65 ft. ANGLE - ZERO

FIRE CONTROL AND TORPEDO DATA

TYPE ATTACK: A periscope depth approach and attack on an
anchored target.

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C-O-N-F-I-D-E-N-T-I-A-L
(H) .ATTACK DATA (continued) .ATTACK NO. 6

Tubes Fired         4            5            6
Track angle         90 P         94 P         91 P
Gyro angle          1 L          5 L          2 L
Periscope           High         High         High
Depth Set           6            6            6
Hit or Miss         One or More Hits
Erratic             NO           NO           NO
Mark Torpedo        14-3A        14-3A        14-3A
Serial No.          39989        23095        25405
Mark Exploder       6-5          6-5          6-5
Serial No.          17350        7944         7955
Mark Warhead        16-1(TPX)    16-0(TPX)    16-1(TPX)
Serial No.          17005        2233         2059
Firing Interval     0            10           13
Type Spread         0            3 L          3 R
Sea Conditions      MODERATE
OVERALL ACTIVITY S/M Repair Unit, Navy No. 137.
REMARKS:

As stated in the narrative, there was good evidence of
one or more hits on this attack. It is possible an exploder
failed.

U.S.S. SPRO (SS309) TORPEDO ATTACK NO. 7 PATROL NO. 4

TIME 0345 (H) DATE 7 August, 1944 LAT. 17-12 N LONG 119-56 E

TARGET DATA - DAMAGE INFLICTED

DESCRIPTION: Large convoy of at least twelve marus, including
tankers; and as many escorts. Convoy was under air
escort day and night.

Contact was made of echo ranging, followed by
sight contact with smoke immediately after completion
of Attack No. 6. Maintained contact until dark,
surfaced and made end around.

SHIP SUNK: One large AK (8000-10,000 tons)

SHIP DAMAGED OR
PROBABLY SUNK One Maru (unidentified).

DAMAGE DETERMINED BY: Observed one hit in large AK, another
hit was heard by sound just before this observation.
Saw target sag in middle; a large volume of water
amidships and the bow rise as the target sank. Dense
black smoke was observed at the scene of the sinking.

Observed ship smoking following an explosion timed
as a hit for one of the torpedoes fired. This hit
was not observed. Ship continued to smoke heavily until
the range had opened and the convoy could no longer
be seen.
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C-O-N-F-I-D-E-N-T-I-A-L
(K) MAJOR DEFECTS AND DAMAGE

1. No. 3 Main Motor. Difficulty was experienced in balancing
the load between No. 1 and No. 3 main motors. Severe sparking
burned about 12 brush holders. Intermittently throughout the
patrol No. 3 had to be disconnected and adjustments made to
compensating field shunt in order to reduce sparking or equalize
the load. The first time the forward end of casing for No. 3
motor was removed one lead from the compensating field shunt was
lying disconnected in the bottom of the casing. Replacement of
the lead partially rectified the trouble at that time. To date
the ships force has been unable to find a shunt setting which will
eliminate sparking at all loads, nor to determine the cause of the
unbalance.

2. Bus Selector. The bus selector was burned out when a
controllerman attempted to close the Generator Bus Tie when two
engines were on one side and one on the other. The stationary
part of the contactor was replaced with a spare and the moving part
filed down so that the bus tie could be used.

3. Gyro Compass. The rotor casings lost vacuum early in the
patrol and latitude setting was put on 50° thinking that the rotor
casings may have been improperly evacuated (no heat run). Later
the gyro fell about 30 degrees off heading in a very few minutes
so the gyro was stopped and defective bearing on spring side of
north rotor renewed. Loose screws were found on the top bearing
piece of the north unit when disassembling the unit. Upon start-
ing up vacuum dropped and remained low in both units so latitude
was left on 50. Numerous azimuths indicated that the unit was
staying close to the meridian.

Upon arrival DARWIN the gyro man sent to meet us and a gyro
man from the Australian Navy advised that they couldn't help with-
out replacement rotors - thought at least one rotor was out of
balance. In view of the delay involved decided to go on with the
gyro as it was.

It held up until 29 July when it took off again. A day was
spent submerged replacing the bearing on the locknut side of north
unit and in cleaning north unit. Metallic particles from the
balls of the bearing were found in the oil and the bearing recess.
All gaskets were renewed but the vacuum could not be made to hold.
The gyro ran satisfactorily with a 50° latitude setting from then
on.

4. Stern Plane Tilting Panel. A coil lead in the stern plane
motor starting panel shorted out causing the overload to trip when-
ever starting the motor was attempted. This was repaired with
no difficulty.

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— page 139 —
C-O-N-F-I-D-E-N-T-I-A-L

(L) RADIO

The best frequency for VIXØ was 9250. Second best was 4370
although interference was generally strong. Reception was generally
good south of MINDANAO STRAIT and generally poor north of there.
On the South China Sea it was necessary to alternate between VIXØ
and VHM. 7555 kcs was best for reception of VHM. 16150 was heard
weakly during daylight, not at all at night. Best hours for
reception of 9250 and 4370 were from 1000 to 1700 GCT.

Voice communication was established with friendly submarine on the
night of 6 August. Insufficient traffic was transmitted to determine
how well we were received. Output was low on the TBL. A re-inst-
allation of the proper wave length antenna will undoubtedly improve
the situation. This antenna, installed during last refit, was
taken down because of the hazard to the stern lookout.

(M) RADAR

The SJ radar was not up to its previous phenomenal performance
this patrol. The antenna packing was replaced at DARWIN because
of salt water leakage. The flywheel was replaced at this time to
eliminate spoking on the PPI scree - the cause of this spoking
was not discovered previously although it was present during the
training period.

On 18 July it was discovered that the SJ ranges were below
standard when the maximum range obtainable on a convoy of medium
sized ships was about 15000 yards. Previously ranges of 20 to 25
thousand yards were obtained on targets of comparable size. Later
ranges on land were 20 to 40 percent below previous ones.

The radar technician, in whom the commanding officer has the
highest confidence, replaced parts and retuned, exploring all
possible sources of trouble to no avail. The remaining unknown
factor was inductance coil Ll which induces a 2000 volt potential.
Kc means was available for measuring this but the voltage across
condenser C19 was 560 V, against a designed 1000 V which indicated
the possibility that coil Ll was partially shorted. No spare coil
is carried on board.

The SJ operated dependably at this reduced effectiveness during
the entire patrol.

The new transmitter key on the SJ was used effectively on
several occasions. It is an ideal means of establishing friendly
identity.

The SD Radar performed well on this patrol. Only one
occasion did lookouts spot a plane appreciably before the SD picked
it up. It appears that the SD is dependable if planes stay out
our blind spots, which is a matter of luck - so far good.

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C-O-N-F-I-D-E-N-T-I-A-L

An embarrassing situation was narrowly averted
when an SD contact was had at 4 miles in MAKASSAR
STRAIT. The plane strafed the periscope shears as the
ship passed 33 feet. Sight contact was never had,
either before or after. The commanding officer is
still in a quandry as to the best employment of the
SD. On this occasion the variac was being turned up
for 5 to 10 seconds every 30. The previous look had
revealed no contact, but the 4 mile one was at saturation.
The inference to be drawn is that the plane would have
been picked up at a much greater range had the SD been
used on a continuous watch.

No materiel difficulties were experienced with the
SD.

(N) SOUND GEAR AND SOUND CONDITIONS

Sound conditions seemed to be average in all the
areas where ships were heard - 15 miles northeast of BURIE
ISLAND in CERAM SEA, along north coast of SOEL ISLANDS,
and off the west coast of northern LUZON. Echo ranging
was heard at 12 to 15 thousand yards, propellers at 4
to 6 thousand.

All echo ranging heard was between 16.6 and 17.6 kcs.

Japanese echo ranging continues to be more of a
help than a hindrance - on every contact with escorts
present the pinging was the first sign of the presence
of strangers. The early notice is invaluable if you are
off the targets track, as sometimes happens.

(O) DENSITY LAYERS

Density layers found are as indicated in the following
table. All gradients encountered extended below 400 feet.
The ship did not pass completely through any of these.

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— page 141 —
C-O-N-F-I-D-E-N-T-I-A-L

(C) DENSITY LAYERS (Continued)

Gradient | Lat. | Time & | Layer | Temp. at | Deepest | Temp. at
No. | Long. | Date (CCT) | Depth | Layer Depth | Submer. | Deepest
| | | | | | Submer.

1 | 4-54S | 0530 | 220' | 78 | 380' | 69
| 125-45E | 18 July | | | |
2 | 2-33S | 2300 | 160 | 79 | 450' | 67
| 127-06E | 19 July | | | |
3. | 1-45S | 0130 | 80 | 80 | 470' | 68
| 124-45E | 20 July | | | |
4. | 1-45S | 0600 | 50 | 81 | 360' | 70
| 124-45E | 21 July | | | |
5. | 17-36N | 0600 | 260 | 65 | 360' | 79
| 120-00E | 28 July | | | |
6. | 17-50N | 1540 | 220 | 80 | 380' | 69
| 119-30E | 28 July | | | |
7. | 19-24 N | 0230 | 160 | 82 | 240' | 70
| 121-35E | 6 August | | | |
8. | 18-22N | 0520 | 300 | 82 | 330 | 78
| 121-46E | 6 August | | | |
9. | 18-22N | 0550 | 280 | 82 | 380 | 74
| 121-44E | 6 August | | | |
10. | 17-50N | 1920 | 200 | 82 | 380' | 74
| 119-37E | 6 August | | | |
11. | 18-08 N | 2000 | 240 | 82 | 360' | 73
| 120-14E | 6 August | | | |
12. | 16-27N | 0000 | 210 | 82 | 300' | 76
| 119-31E | 7 August | | | |
13 | 16-27N | 1100 | 240 | 83 | 340' | 76
| 119-31 E | 7 August | | | |

- 40 -

— page 142 —
C-O-N-F-I-D-E-N-T-I-A-L

(P) HEALTH, FOOD AND HABITABILITY

Two men were on the sick list upon departure from FREMANTLE.
One was a back injury, the other an abscessed tooth. Both were
taken with the consent of the Medical Officer. Upon arrival at
DARWIN the back injury showed no improvement so was transferred
as had been intended in this eventuality. The abscessed tooth
was extracted by Army dental authorities with no complications,
the patient returning to duty shortly thereafter.

One man received from the relief crew complained of tooth
trouble enroute DARWIN. Army authorities there filled ten
cavities in eight teeth for this man. That such a condition
existed in a man newly reported aboard is faint praise for the
thoroughness of the physical examination reputedly given before
reporting aboard.

B.L. EONDO, Lieutenant (MC), USN., at DARWIN is deserving
of commendation for the efficient and painstaking manner in
which he attended to all ills.

At the prescribed time after departure from DARWIN three
suspected gonorrhea cases turned up. These responded to sulfa
treatment in a few days.

In all other respects the health was normal.

Food and habitability were the same as ever.

(Q) PERSONNEL

The performance of duty of all hands was highly commen-
dable. As long as replacements from relief crews have
ordinary intelligence and are eager to go to sea, as the
majority seem to be, there will be no great difficulty in
maintaining a well rounded crew.

The facilities and organization for sending men to schools
during the training period is exceptionally good at FREMANTLE.
The arrangement of the training schedule enabled the ship to
take advantage of all training facilities desired without depriving
new men of the valuable training acquired at sea during the training
period.

It is recommended that a short intensive Mark 13 Torpedo school
be inaugurated primarily for ships crews during the training period.

It is of great value if men from the relief crew, particularly
new seamen making their first patrol, have had instruction in
lookout, 20 m.m., radar operators, and sound operators schools,
or as many of these as circumstances permit.

- 41 -

— page 143 —
C-O-N-F-I-D-E-N-T-I-A-L
Number of men on board                                  - 72
Number of men advanced in rating during this patrol     - 16
Number of men qualified during this patrol              - 6
Number of unqualified men remaining at end of patrol- 9

(R) MILES STEAMED - FUEL USED

Fremantle to Darwin       1730 Miles     19640 gallons.
Darwin to area            2878 miles     30085 gallons.
In area                   1939 miles     12600 gallons.
Area to Fremantle         3317 miles     45450 gallons.

(S) DURATION

Days enroute area         18
Days in area              12
Days enroute Fremantle    11
Days submerged            11
Days north of Barrier     26

(T) FACTORS OF ENDURANCE REMAINING

Torpedoes                 Fuel           Provisions     Personnel Factors
0                         *39190         40             25

*Upon arrival Exmouth Gulf
Limiting factor was expenditure of all torpedoes.

(U) Remarks -

None

- 42 -

— page 144 —
SUBMARINE SQUADRON TWELVE
Care of Fleet Post Office,
San Francisco, California,
20 August 1944.

FC5-12/A16-3/

Serial 0163

FIRST ENDORSEMENT to
USS ASPRO - Report of
Fourth War Patrol.

CONFIDENTIAL

From: The Commander Submarine Squadron TWELVE.
To : The Commander in Chief, United States Fleet.
Via : (1) The Commander Submarines SEVENTH FLEET.
 (2) The Commander SEVENTH FLEET.

Subject: U.S.S. ASPRO (SS309) - Report of Fourth War
 Patrol - comments on.

 1. The fourth war patrol of the U.S.S. ASPRO was of
41 days duration. Fourteen torpedoes were expended in four
attacks while enroute to the assigned patrol area west of Luzon
and the remaining ten torpedoes were fired in three attacks
during the eleven days in the area. The entire patrol was
aggressively and skillfully conducted and attacks were pushed
home on all worthwhile contacts.

 2. Attacks 1, 2 and 3. A convoy was picked up by
radar at 0220 on 19 July at 15,500 yards. ASPRO gained position
ahead of convoy and dived to deliver a dawn periscope attack.
Dawn disclosed convoy to consist of four medium Marus and five
escorts. ASPRO gained favorable attack position, range 1,800
yards, and fired four torpedoes at the second Maru from the
left (attack #1), and two torpedoes at the third Maru from the
left (attack #2). The ship was swung and four torpedoes fired
from the stern tubes at the right hand Maru in the formation
(attack #3). One hit was heard and two more observed on the
first target and three hits were heard from the stern tube
salvo. The two torpedoes fired at the second target probably
missed as the target changed course to parallel the wakes.
Escorts dropped several depth charges none of which were very
close.

 Attack No. 4. While patrolling, submerged and
working on the starboard shaft, contact was made with a medium
AK with two escorts. Four torpedoes were fired at the AK.
While no hits were seen or heard, the target was obscured by
smoke or spray when periscope observation was made 1-1/2 minutes
after firing. ASPRO was forced to deep submergence by prompt
counter measures and was severely depth charged.

 Attack No. 5. ASPRO proceeded close inshore
submerged and fired three torpedoes at an anchored Maru. All
torpedoes hit but the ship evidently managed to beach itself
as it was observed seven days later badly gutted by flames and
hard aground.

-1-
[STAMP: 9 04091]

— page 146 —
FE24-71/A16-3
Serial 0945
UNITED STATES NAVY
12a/pr
AUG 30 1944

C-O-N-F-I-D-E-N-T-I-A-L

SECOND ENDORSEMENT to:
USS ASPRO - Report of
Fourth War Patrol.

From: The Commander Submarines, SEVENTH FLEET.
To: The Commander-in-Chief, UNITED STATES FLEET.
Via: The Commander, SEVENTH FLEET.
Subject: U.S.S. ASPRO (SS309) - Report of Fourth War Patrol -
         Comments on.
[HANDWRITTEN: 901953]
         1. ASPRO'S Fourth War Patrol was conducted in the CHINA
SEA off the West Coast of LUZON. Two ships were sunk in the
MOLUKKA SEA enroute to the assigned area.

         2. All worthwhile contacts were developed with skill
and determination. The night end-around run on a large, heavily
escorted, and air covered convoy was particularly commendable. In
addition to being driven down by a plane at close range, ASPRO was
twice forced to deep submergence in order to evade escorts which
apparently had made echo-ranging contact. In spite of these counter
measures, the Commanding Officer was able to return to periscope
depth in time to fire his last four torpedoes and sink one AK and
damage another.

         3. The complimentary remarks of the Commanding Officer
concerning the school facilities available to the crew during the
training period are noted with pleasure.

         4. It is regretted that there is insufficient evidence
to justify assessment of damage on Attack No. 4 although there is
a probability that one torpedo hit the target and failed to
explode.

         5. This patrol is designated "successful" for the award
of the Submarine Combat Insignia.

         6. The Force Commander takes pleasure in congratulating
the Commanding Officer, Officers, and Crew, on this very
successful patrol in which the following damage was inflicted on
the enemy:

[HANDWRITTEN: +]
         - 1 -

— page 148 —
UNITED STATES FLEET
COMMANDER SEVENTH FLEET
[HANDWRITTEN: 1232-A]
[STAMP: 9 C4091]
[STAMP: 21 SEP 1944]
[HANDWRITTEN: 9 July]
[HANDWRITTEN: 18 Aug 44]

A16-3(1)(F-3/roj)
Serial: [HANDWRITTEN: 087-A]

C-O-N-F-I-D-E-N-T-I-A-L [HANDWRITTEN: ✓]
THIRD ENDORSEMENT to:
USS ASPRO - Report of
Fourth War Patrol.

From: [HANDWRITTEN: Commander Seventh Fleet.]
To : [HANDWRITTEN: Commander-in-Chief, United States Fleet.]

Subject: [HANDWRITTEN: U.S.S. ASPRO (SS309) - Report of Fourth]
[HANDWRITTEN: War Patrol.]

1. [HANDWRITTEN: Forwarded.]

[SIGNATURE: R. H. Cruzen]
R. H. CRUZEN,
By direction.

[HANDWRITTEN: x]

— page 150 —
[HANDWRITTEN: 1ST COPY]

U.S.S. ASPRO (SS309)

SS309/
Serial 017
[STAMP: DECLASSIFIED-A-L]

Care of Fleet Post Office,
San Francisco, California,
25 October, 1944.

From:             The Commanding Officer.
To :             The Commander in Chief , U.S. Fleet.
Via :             Official Channels.

Subject:          U.S.S. ASPRO (SS309) - Report of War Patrol
                  Number Five.

Enclosure:        (A) Subject Report.
                  (B) Two Track Charts.

1.        Enclosures (A) and (B) covering the fifth patrol of this
vessel conducted in the area in the South China Sea from the coast of
LUZON to meridian 115 E between latitudes 16-30 N and 18-30 N during
the period 10 September, to 25 October, 1944, is forwarded herewith.

[SIGNATURE: W. A. STEVENSON]

DECLASSIFIED-ART. 0445, OPNAVINST 5510.1C
BY [HANDWRITTEN: OP-09B4C] DATE [HANDWRITTEN: 5/23/72]
[STAMP: DECLASSIFIED]

[HANDWRITTEN: 93092]

— page 151 —
C-O-N-F-I-D-E-N-T-I-A-L

PROLOGUE

     Arrived FREMANTLE, W.A. from fourth war patrol 18 August, 1944.
Commenced refit by SUBMARINE REPAIR UNIT, NAVY 137 assisted by U.S.
Submarine Advanced Training and Relief Crew No. 6. Refit completed 1
September, 1944. Conducted sound tests and miscellaneous underway
2-5 September. Conducted training, 5-8 September; fired three exercise
torpedoes including one Mark 18. Fueled and provisioned 8-9 September.
Departed on fifth war patrol 10 September, 1944. All times unless
otherwise noted are zone (-) 8, HOW time.

NARRATIVE

10 September, 1944

1330 Underway from alongside U.S.S. EURYALE for fifth war patrol.

1530-2100 Conducted practice approaches and training in exercise area
with target, HMAS MILDURA. Conducted night coordinated attack exercises
with U.S.S. CABRILLA.

2100 Departed exercise area, enroute DARWIN, N.A.

10-17 September, 1944

     Enroute DARWIN, N.A.; conducted training enroute.

17 September, 1944

0530 Exchanged signals with escort, ML 813.

0840 Moored port side to BOOM DOCK, DARWIN, N.A. Received 20270 gallons
diesel fuel, fresh provisions, and water.

1437 Underway from alongside BOOM DOCK, DARWIN, N.A. Enroute patrol
area west of LUZON to conduct wolf pack operations with HOE and
CABRILLA. OTC Commanding Officer HOE.

18 September, 1944

0950 Dove.

0957 Battle surfaced and fired all guns at target constructed from
materials obtained in DARWIN.

1001 Sighted friendly submarine on opposite course distant about
13000 yards. Exchanged recognition signals with U.S.S. STINGRAY.

1400 SD contact 10 miles. Dove. Surfaced ten minutes later.

1558 SD contact 16 miles - closing.

1600 Dove. Surfaced thirty minutes later. The radar detector had
indications of interference on 145 megs before this contact.

1809 SJ radar interference.

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— page 152 —
C-O-N-F-I-D-E-N-T-I-A-L
1825 Exchanged recognition signals with U.S.S. NAUTILUS.
1914 Commenced passage into the BANDA SEA via route east of TIMOR
     in bombing restricted lane.

18-25 September, 1944
     Enroute station via FLORES SEA, MAKASSAR STRAIT, SIBUTU
     PASS, SULU SEA, and BALABAC STRAIT. Made daily dawn dives,
     conducted training.

19 September, 1944
1552 SD contact 8 miles. Dove. Surfaced thirty five minutes
     later.

20 September, 1944
0520 Dove.
0604 Sighted small sail sampan.
1043 Surfaced.
1125 SD contact 9 miles and 4 miles. Dove. Surfaced ten
     minutes later. It is believed these were not plane contacts,
     and may have been caused by radar interference.
1643. Sighted sail sampan dead ahead at extreme range.
1714 Fired a few bursts of 20 m.m. ahead of sampan to get them
     to lower their sails.
1725 Hauled sampan alongside. Identified as native craft with
     six badly scared natives aboard. They could speak no English.
     We gave them bread, cigarettes, etc. and parted good friends.

21 September, 1944
     Sighted numerous sail sampans during the day in MAKASSAR
     STRAIT near CAPE MANDAR.
0639 SD contacts 6 miles and 12 miles. Dove. Surfaced fifty
     minutes later.
0750 SD contact 6 miles. Dove. Surfaced thirty minutes later.
1149 SD contact 12 miles. Dove. Surfaced forty minutes later.
1407 SD contact 16 miles, closed to 10 miles. Dove. Surfaced
     twenty five minutes later.

22 September, 1944
1235 SD contact 30 miles.

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— page 153 —
C-O-N-F-I-D-E-N-T-I-A-L
1241 SD contact closed to 10 miles. Dove. Surfaced forty minutes later
1544 SD contact 22 miles.
1550 Sighted flight of seven planes, distant about 12 miles. Dove.
Surfaced twenty five minutes later.
1832 SJ radar interference.
1840 Exchanged recognition signals with U.S.S. CABRILLA.
2110 Commenced transit of SIBUTU PASS.
2300 Completed transit of SIBUTU PASS.
23 September, 1944
0830 Sighted small sail sampan distant about eight miles.
0911 Sighted two small sail sampans on our track and distant about
eight miles.
0953 Sail boats lowered their sails without our firing a shot. As
we approached they were shouting "Victory!, Victory!" They were
native Filipinos, twenty in number, enroute TAI TAI. Many of them
could speak fairly good English, however, we learned nothing of
military importance. They were well aware that we were American
submariners. Gave them bread, crackers, cigarettes, etc. and parted
on excellent terms.
1427 Sighted another small sail sampan.
1658 Dove. Submerged to test depth.
1711 Surfaced.
24 September, 1944
0230 SJ radar interference.
0352 Exchanged signals with U.S.S. CABRILLA.
0704 SD contact 10 miles - closing. Dove. Surfaced twenty five
minutes later.
0836 Sighted formation of seven planes at extreme range, and a single
plane closer in headed in our direction. Dove. Surfaced fifty minutes
later. For some time prior to this contact, the SD had been reporting
contacts between 25 and 30 miles.
1430 Passed APO light abeam to port distant 9 miles in EAST CUYO PASS.
1455 Sighted a plane distant about 7 miles. Dove.
1847 Surfaced in heavy rain squall.
- 3 -

— page 154 —
C-O-N-F-I-D-E-N-T-I-A-L

2150 Contact on SJ, range 16,000 yards. Commenced tracking. It
was a very dark night with almost continuous light rain fall with
occasional cloud bursts when visibility would be reduced to zero.

2215 Target tracked beautifully on a steady course of 213 T at 9½
knots. There were no other contacts. It looked suspicious.

2247 At a range of 8500 yards the visibility improved and the running
lights and deck lights of a ship could be made out. It was obvious
now that this was a hospital ship. Decided to close the range for a
better look.

2258 When the range had closed to 4900 yards a heavy rain squall
reduced visibility to zero.

2300 Broke off approach and opened range. Although the visibility
was never good enough to make out whether the ship had proper markings
of a hospital ship, there is no doubt in the commanding officer's
mind that the contact was a hospital ship.

25 September, 1944

1400 Arrived in patrol area. ASPRO will conduct independent patrol
until scheduled rendezvous with HOE and CABRILLA on 30 September.

26 September, 1944

0537 Dove.
0614 Surfaced.
0742 Sighted two planes distant 8 miles. Dove.
1834 Surfaced.

2000 SJ radar interference.

2043 Exchanged recognition signals and information with CABRILLA key-
ing SJ. It was decided to conduct a coordinated search patrol until
arrival of HOE. O.T.C. - Commanding Officer of CABRILLA. He had also
received dispatch instructions to stay east of longitude 118 E
until 9 October, 1944.

27 September, 1944

Surface patrol with CABRILLA at interval of twenty miles,
courses east and west at 10 knots.

0724 SD contact at 24 miles.

28 September, 1944

0537 Made trim dive.

0600 Surfaced. Continued surface patrol with CABRILLA.

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2215 Observed what appeared to be smoke - no radar contact. Closed
     to investigate. Visibility excellent.

2230 Made sight contact with small patrol boat, PC type or smaller.
     Radar contact on this patrol boat - 11,800 yards. No echo ranging
     could be heard. Decided to work around this patrol boat to the south
     to investigate possibility of a north bound convoy. No luck.

2300 Attempted to regain contact with patrol boat. The patrol boat
     had been contacted off CAPE BOLINAO and it is believed he was conducting
     a patrol of the entrance to LINGAYEN GULF.

29 September, 1944

0530 Made trim dive.

0758 Surfaced.

0925 SD contact 6 miles. Sighted plane. Dove.

1822 Surfaced.

2300 Exchanged information with CABRILLI by keying SJ. We will
     conduct a submerged patrol tomorrow close to the beach.

30 September, 1944

0529 Dove.

0607 Sighted plane.

0905-0939 Heard a total of 63 distant depth charges. They were
     distant but sounded like block busters.

0943 Sighted smoke and masts of ship, identified as a trawler.

0957 Sighted seven sea trucks heading up the coast.

1025 Sighted smoke to the northeast and heard pinging in that direction
     Came to normal approach course.

1043 Identified contact as convoy of seven, possibly eight marus,
     exclusive of escorts. There were seven distinct columns of smoke.
     Sound reported at least four sets of echo ranging.

     Continued to close the track at 8 knots at 150 feet and taking
     an observation every 15-20 minutes.

1120 Sighted two planes over convoy.

     Numerous sea trucks and motor sampans were sighted during the
     approach. They were all proceeding on the same or opposite course of
     the convoy. We crossed the track of several of these small craft during
     the approach.

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1224 Plane approached from dead astern flying so low it looked like
he was going to hit our periscope. We were evidently not seen.

1238-35 Commenced firing six bow tubes at a large freighter with
about 30% of another freighter in the far column over lapping, and
an escort distant about 1000 yards just ahead of the freighter's
bow; torpedo run - 1700 yards, 98 degree starboard track, gyro
angle - 11½ left, 3 degree spread between torpedoes.

The closest escort was on the port beam with a small angle. Went
deep and commenced evasive tactics.

1240-14 Torpedo explosion.
1240-24 Torpedo explosion.
1242-40 Commenced receiving 43 depth charges.

1255 Heard breaking up noises on the sound gear for the next 15-20
minutes.

1318 Started up to periscope depth.

1321-33 Heard one fairly loud explosion, possibly an internal
explosion on a ship. It was definitely not like any depth charge ever
heard.

1325 Remained at deep submergence. Commenced reload.

1355 At periscope depth, sighted three planes flying low over the
convoy. There were definitely only the smoke and the tops of six
merchant vessels in sight. Nothing could be seen in the direction
of the attack, but we continued to hear echo ranging on this bearing
for the next hour. Sound reported that there were three ships echo
ranging.

1420 Formation of five planes flew overhead flying up the coast.

1517 The three escorts had formed a scouting line on a westerly
course. Only two could be seen through the periscope. It looked
like they would pass to the northward. The closest one was distant
12,000 yards.

1535 Observed plane on port beam in low power sweep. Plane was in
a dive. Went to 150 feet.

1605 At periscope depth. The closest escort had a zero angle,
distant about 7000 yards. The plane must have sighted us and
called the escorts over. Went to deep submergence.

1635 One escort crossed our stern. The second escort's screws
could be heard - he must have passed us fairly close.

1700 Echo ranging continued as the escorts opened the range.

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1745 At periscope depth. There was nothing in sight. Continued
    to hear echo running astern in the direction of land.

1753 One depth charge. Observed plane circling the probable
    position of the escorts.

1801-1805 Heard 28 depth charges.

1825 Surfaced and opened range.

2230 Rendezvoused with CABRILLA. The HOE did not make the
    rendezvous. Received instructions from CABRILLA to conduct independent
    patrol in the northern part of area and to rendezvous tomorrow night
    if convenient, if not, the following night. Decided to conduct
    submerged patrol off DILE POINT tomorrow.

2357 Made sight and SJ radar contact, 5500 yards, with plane. Dove.

1 October, 1944

0005 Observed plane circling. The plane had a steady white light,
    which at times appeared green. This was possibly exhaust, but it was
    a steady light.

0010 The plane banked and headed for our periscope. The commanding
    officer was not certain of this at the time, but lowered periscope.

0011 Raised periscope and observed flare burning in water very close
    astern. Went to 150 feet. Decided plane had picked up our periscope
    by radar, but still can't understand the flare.

0059 At periscope depth. All clear.

0111 All clear by radar.

0113 Surfaced.

0326 SJ contact 6000 yards. Suspected another plane contact. Dove.

0328 All clear at periscope depth.

0338 All clear by radar.

0341 Surfaced.

0516 Submerged for periscope depth patrol.

0545 Sighted plane, transport type.

0935 Sighted three small motor sampans close to beach.

1055 Sighted wrecked ship identified as transport we put on bottom
    with three hits on our last patrol. Decided to close to get a better
    look. It looked like the bow had broken off.

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1358 Backed again and blew negative, without result.

1400 Secured everything, vented safety inboard, started pumping from
     auxiliaries.

1404 Depth charge. This must be a plane.

1425 Went ahead two thirds and started to come up from 100 feet.

1429 Grounded again at 70 feet. Backed full, and we broached.
     All clear by periscope except a small sampan and our two marus going
     away. Surfaced.

1430 As soon as we were on the surface we sighted a bi-plane circling.
     The plane started to make an approach and then circled away. We
     were still kicking up mud aft.

1432 Dove when plane started his dive.

1433 Bomb went off when we were passing 50 feet, not too close.
     Continued to open out from coast in search of deeper water.

1501 Sighted three planes.

1645 Went to deep submergence to test condition of boat.

1700 There appears to be nothing serious resulting from the groundings
     except both sound heads are out of commission. The JK sound head is
     in the rigged out condition and can not be trained. The QB could only
     be partly raised. The sea chest could be almost completely closed,
     indicating the head had been knocked off. Rigged up positive stop
     to prevent shaft from being pushed up on deep submergence.

1817 Surfaced.

1910 Sent ASPRO serial TWO.

     Decided not to attempt rendezvous tonight but would dive in
     close to the coast again tomorrow in an attempt to intercept the two
     contacts we failed to stop today.

2300 Radar interference. This was definitely SJ interference but we
     were unsuccessful in exchanging recognition signals.

2 October, 1944

0405 Made intermittent radar contact, 11,000 yards, bearing 030 T.
     This was the center of strong radar interference. We have had this
     interference most of the night. Repeated attempts to exchange recognit-
     ion signals were unsuccessful. It was too late to investigate this
     contact before daybreak. We were reasonably certain it was a
     friendly submarine.

0523 Submerged for periscope depth patrol.

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0538 Sighted ship bearing 100 T with a large port angle. Contact was identified
as yesterday's tanker. Came to normal approach course. We dove
five miles off the beach and it looked like the tanker was
hugging the coast - it was going to be a long chase.

0545 Sighted the second maru ahead of the tanker. There was
either the same trawler with them or a sampan.

Continued approach by running at 8 knots at 100 foot and
taking a look every 25 minutes.

0753 The tanker was plotted at 6½ knots and following the contour
of the shore line. We were not closing the range but we were clos-
ing the coast, and the bearing was remaining steady. We would
be able to reach a firing position (provided we didn't run out
of "can") when the tanker changed course to clear CAPE BOJADOR.

0801 Observed two low flying planes over BOJADOR, and saw masts
of what was thought to be a south bound convoy. This contact was
later identified as three large sea trucks.

0825 Tanker finally changed course.

0846-48 Started firing four torpedoes from the bow tubes:
torpedo run - 2700 yards, 120 degree pert angle, 1 degree left
gyro, 1 degree spread between torpedoes. Went to 90 feet and
changed course to get off track of torpedoes.

0848-50 Two hits about two seconds apart.

0849-33 One torpedo explosion.

0850 Aircraft bomb.

0852 At periscope depth observed tanker with bow in the air at
an angle of 70 degrees going down. Heard breaking up noises for
next ten or fifteen minutes.

0900 Aircraft bomb. At 150 feet opening out from coast.

0902 JP reported screws.

0905 Observed freighter, identified as the other maru of the two
ship convoy, with a large starboard angle distant approximately
3400 yards. Came to a parallel course and started approach.

0920 Freighter was stopped and there was a small boat alongside
their port bow. They were evidently picking up survivors. There
was a plane circling the freighter. Headed for freighter.

0950 Maneuvered into position for a stern tube shot.

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0955-43 Started firing three torpedoes from the stern
  tubes: torpedo run - 1800 yards, 44 degree starboard
  track, 12 degree left gyro, 1½ degree spread between torpedoes
  Went to 150 feet.
0957-07 Torpedo explosion.
0957-40 Torpedo explosion.
0958 Bomb
0959 Two bombs
1001 One bomb - close.
1002 One bomb
1009 At periscope depth observed freighter down slightly by the
  stern; the last 50-75 feet of the stern had sagged about 15 feet.
  A quick set up indicated ship was underway.
1012 One bomb - close. Observed plane medium bomber on port beam
  bank and head in again. Went to 150 feet.
The plane was apparently having no difficulty seeing us at
  periscope depth. Our battery was very low. Decided against further
  attack due to the present state of the battery, and the fact that
  we were well known in this area.
1020 One bomb. Continued to open out from coast.
1816 Surfaced.
1827 SJ radar interference to the north of us. This was probably
  the same interference experienced last night.
Attempted unsuccessfully each hour to exchange recognition
  signals.
2245 Exchanged recognition signals with CHERRILL at the rendezvous.

3 October, 1944
0004 Momentary SJ radar contact, 3800 yards opened to 5700 yards.
  This was probably a plane, although visibility was excellent and we
  should have sighted any plane at that range.
0130 Rendezvoused with HOE and CHERRILL. Received instructions to
  conduct submerged patrol tomorrow in the area north of DILI POINT.
0525 SJ radar contact bearing 337 T distant 19,000 yards. Stationed
  radar tracking party and came to southerly course to open range.
0540 Identified contact as large single freighter with a large port
  angle. Started and around, keeping tops in sight through high
  periscope. The maximum radar range obtainable was 25,000 yards and
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we were too close to him at this range. The short time we did track
him indicated he was making very slow speed.

0600 Attempted to send contact report to HOE and C.BRILL - no
luck.

0708-0723 Had several SD contacts at 16,12, and 10 miles.

0723 Sighted two planes. Dove. We were very nearly in position
ahead and would be easily able to conduct approach submerged.

0803 Continued approach. Freighter was tracking at 1½ knots on
course 230 T., heading on course 250 true. Decided to fire two
stern torpedoes. Because of very rough seas, decided to set one
on 8 feet and one on 10 feet.

0913 Freighter was definitely identified as freighter we damaged
yesterday. His anchor chain was out. It was quite possible
he dragged anchor during night.

0928-59 Fired torpedo from No. 7 tube: torpedo run - 2200 yards,
92 degree starboard track, 3½ degree right gyro angle.

0929-13 Fired torpedo from No. 8 tube: torpedo run - 2200 yards,
93 degree starboard track, 4½ degree right gyro angle.

0931-22 Torpedo explosion. JP reported both torpedoes hit about
three seconds apart. Periscope ducked at this time and hit or hits
were not observed. The stern settled some from the hit but it
would take another torpedo.

Commenced closing in order to fire bow tubes. There was no
sign of life on board.

0943 JP reported noises in the direction of the target.

0955-27 Fired torpedo from No. 1 tube: torpedo run - 1500 yards,
101 degree starboard track, zero gyro angle.

0956-46 Observed torpedo hit just aft of MOT. The target commenced
to settle aft. However the ship did not appear to be sinking fast
enough.

0957-43 Fired torpedo from No. 2 tube: torpedo run -1450 yards,
104 degree starboard track, 2½ degree right gyro.

0958 The freighter's bow was now in the air - the last torpedo was
unnecessary. Took periscope pictures of the sinking.

1002 Ship sunk in a vertical dive, stern first. Continued to hear
breaking up noises on the JP for fifteen minutes.

1820 Surfaced. Headed for rendezvous with HOE and C.BRILL.

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— page 163 —
CONFIDENTIAL

2035 SJ contact, 5500 yards. Dove. The size of the pip indicated
this was probably a plane. We were evidently never detected, due
partially to the very rough seas. All clear at periscope depth.

2043 Surfaced, all clear by radar.

2330 Rendezvoused with HOE and CABRILLA. Received instructions for
surface patrol tomorrow.

4 October, 1944

0052 Set course for surface patrol station.

0739 SD contact 26 miles.

1900 Received instructions for submerged patrol tomorrow. Set
course for DILE POINT, station for tomorrow's patrol.

5 October, 1944

0527 Dove to conduct submerged patrol 3-4 miles off coast.

During the day sighted a total of 12 planes.

0950 Sighted small trawler in close to the beach.

1220 Surfaced.

1223 Had strong radar interference, 130 mgs on APR-1 detector.

6 October, 1944

0115 Received instructions for submerged patrol tomorrow off DARIC YCS
POINT.

0442 Made sight and radar contact, 10,000 yards with patrol boat.
The patrol boat had a large port angle and was evidently conducting
an anti-submarine patrol up the coast. The HOE had reported two
minesweepers in this area yesterday. Avoided and continued to
close the coast.

0508 Dove.

0615 Sighted smoke to the south, believed this was a northbound
convoy.

0650 Sighted the tops of at least seven ships. A float type plane
was circling the convoy. Started approach.

0711 We were on the convoy's track, most of the ships had a zero
angle, distant 12,000 yards. One small escort was about 7000 yards
ahead of the convoy and had a zero angle.

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0725 Went to 200 feet to duck under leading escort, now about 2000
yards away.

0728 Escort speeded up, and we received three close depth charges.
Went to 350 feet. It is hard to believe he sighted our periscope.
Maybe he had an echo range contact.

0747 Started to come up.

0754 The convoy had zigged away, and were to seaward of us. The closest
escort, a DE was observed to have at least 50 men topside in
whites; all hands were lookouts.

0809 Went to 250 feet to close tract at 8 knots.

0822 Started up to periscope depth. Sound started reporting screws
on several bearings.

0828 At periscope depth. The convoy had zigged back to their base
course. We had crossed the track of the inshore column. A large
tanker was dead astern and so close he covered the field in high
power; several maru's were on the port beam, one was crossing our
bow close aboard; no escorts could be seen close aboard. Made all
tubes ready. Decided to fire at tanker first and then fire at
freighter.

0829 Raised periscope for final set up. Heard strafing of machine
gun fire.

0830 Started firing three remaining torpedoes from the stern tubes
at the tanker: torpedo run - 1700 yards, 142 degree port track, 43
degree left gyro angle, 2 degrees spread between torpedoes.
Continued to hear strafing during the firing. Tried to find freighter
in periscope and discovered he had crossed our bow and had close to
a 180 angle. Quick sweep revealed no escorts but went deep anyway.

0832 (approx.) One definite torpedo hit was heard by personnel in
the after torpedo room. Sound was busily engaged reporting position
of ship contacts and did not follow torpedoes to target, there could
possibly have been other hits.

0837 Started receiving 14 depth charges. The first couple of
explosions may not have been depth charges - they were on the order
of a low rumble.

0846 Two depth charges.

0913 Started to come up to periscope depth.

0922 At periscope depth. Counted 12 marus and four escorts (there
may have been more). We could not see the tanker. A large engine
aft ship could be seen but this was identified as a freighter with
a very distinctive mast arrangement. The tanker we fired at looked
new and had a clean design. The number 545 was painted on the stack.
Three of the escorts were still in the vicinity of the attack. If

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C O N F I D E N T I A L

They hang round long enough it will be an assistance to the
CABRILLA - she is just north of us.

1042 Sighted a dense amount of white smoke either on the beach or
close to the beach. One escort had closed to about 8000 yards and
was patrolling in our direction. Went to 300 feet.

Escort continued to search in our vicinity for one hour.

1145 Lost escorts screws on JP.

1627 Sighted two planes.

1822 Surfaced. Headed for rendezvous with HOE and CABRILLA.

7 October, 1944

0049 Received instructions for submerged patrol tomorrow just
south of CAPE BOJEADOR. Headed for tomorrow's patrol station.

0230 Received contact report from HOE of a many ship convoy headed
south. Changed course to intercept with best available information
which included an apparently incorrect latitude. Asked HOE for
report on the latitude.

0255 Received corrected latitude from HOE. Continued to receive
amplifying reports on target's course and speed from HOE.

0310 Made radar contact with convoy, 23,400 yards. Commenced
tracking. During the tracking sent two messages giving target's
course. HOE receipted, but we were never able to raise CABRILLA.

0406 Heard possible depth charging.

0415 Received message from HOE directing ASPRO and CABRILLA to make
attack from starboard side and HOE "will attack if possible". At
this time we were on the port bow of the convoy and it looked like
a close race to make attack before dawn.

0435 Received message from HOE that HOE had completed attack
number two. We were in position for an attack on the port side -
headed in for attack.

0442 Radar picked up second target group closer in and about 10
degrees to the left. Shifted to a large freighter in this group.
Visibility was good with a moon overhead. A hazy horizon would
make a surface approach possible. The target group could be seen at
a range of 8000 yards. Since it would be light in a half hour and we
only had torpedoes for one approach, decided to make a radar depth
approach.

0450 Went to radar depth at 4500 yards.

0455 Ordered 60 feet - lost radar range 3000 yards. The target had
zigged away about twenty degrees.

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0456-30 Started firing four torpedoes from the bow tubes: torpedo run - 2700
          yards, 102 degree port track, 18 degree right gyro, 1 degree spread
          between torpedoes. We were still at a depth of about 52 feet
          during the firing and trying to get down. We went to about 65-70
          feet after firing and as a result the hits were not observed.

0458-40 First torpedo hit.

0458-52 Second torpedo hit.

0458-57 Third torpedo hit.

0459 Observed freight escort on our starboard side with about 40 degree starboard
          angle. There was nothing else close.

          Observed target settling. The bow was at an angle of about
          40 degrees, and she was completely under up to the deck house.

0501 Sound reported loud explosion on the bearing of the target.
          The commanding officer was looking at the escort at the time. The
          freighter could not be seen after this report. Went to deep
          submergence. Commenced retirement along Convoy's base course.

          Received a total of nine depth charges. None of these were
          close and several were dropped while we were still at periscope
          depth. The escort who was close to us was definitely not responsible.

0529 One depth charge. Escorts continued to mill around.

0535 Explosions reported by JP.

0539 One explosion, distant.

0617 Two depth charges.

0622 Escort crossed over us. Continued to hear screws and echo
          ranging for the next hour.

0940 Heard 22 depth charges - not too far away.

1247 Twelve more depth charges.

1315 At periscope depth, all clear.

1500 Surfaced.

1607 Sighted five ships through the high periscope. A large
          part of their hulls were visible and they had a small angle. Dove.

1624 Surfaced. We had been unable to see them at 40 feet.

1627 Regained contact with convoy. Maintained contact by keeping
          tops in sight. It soon became apparent that the ships were steering
          no set course, but were milling around. It looks like we have
          stumbled on to a rendezvous and this may be part of this mornings
          - 16 -

— page 167 —
CONFIDENTIAL
convoy. Attempted to send contact report to HOE and CABRILL, without
success.

1729 Identified a sixth maru closing the rendezvous.
1730 Sent ASPRO serial three.
1735 Received message from CABRILLA giving 1300 position of
convoy, that she was not in contact, and had zero torpedoes. The
CABRILLA was unable to hear our receipt.
1824 Made radar contact with convoy, 23,000 yards. Commenced tracking.
1900 Attempted to send contact report to HOE giving convoy's present
position, course, and speed. The HOE and CABRILLA could both be heard
clearly, but neither could hear us.
1927 Sent contact report using CW. CABRILLA receipted for our
message and relayed the message to HOE. It was gratifying to hear
CABRILLA relay message correctly to HOE, and HOE receipt for it.
2015 Received message from HOE to continue tracking until midnight
and then head for home, and that they were closing convoy.
Continued to track and send amplifying reports using CW on the
voice frequency.

8 October, 1944

Tracking convoy. We had had the HOE's radar interference for
a couple of hours, but we were pretty sure they were not in contact.
0058 Received message from HOE asking us to continue tracking until
they made contact.
0115 Exchanged calls with HOE by keying SJ.
0158 HOE reported they had contact. Turned convoy over and headed for
home.
0713 SD contact 12 miles. Dove.
0736 Started to surface after report of all clear on SD, when SD
contact at 10 miles suddenly appeared on screen. Went to 100 feet.
0750 Surfaced.
0800 Shifted to the operational control of ComSubPac.
0900 Received orders from ComSubPac to rendezvous with WHALE to
receive latest submarine notices and instructions and to receive man
with infected eye and take him to SAIPAN. CABRILLA was to proceed to
PEARL after rendezvous.

- 17 -

— page 168 —
CONFIDENTIAL
1220 SD contact 13 miles. Dove.
1304 Started to surface after report of all clear on SD when
a grin a contact at 12 miles appeared on SD screen. Went to 100 feet.
1331 Surfaced.
1345 SD contact 12 miles. Dove. Surfaced 55 minutes later.
1520 Sighted plane, 150 relative, headed for us, distant about
12 miles. Dove.
1523 At periscope depth. Observed plane, very close, with a zero
angle. Went to 150 feet.
1529 Back at periscope depth, observed plane flying away on course
of zero. The plane, ELVIS, had flown directly over us. Continued
to observe plane through the periscope for the next 40 minutes.
He was flying a square, about 8 minute legs.
1610 Lost plane in cloud at extreme range.
1650 Surfaced without turning on SD.
1810 SJ radar interference.
- 1830 Exchanged recognition signals and calls with CABRILLA by
keying SJ.
2230 Changed course to head for 20-00 N, 120-00 E, after receipt
of WHALE's message telling us she could reach this rendezvous by
0230, and the designated rendezvous, not before daybreak.

9 October, 1944
0045 Picked up radar interference bearing 260 T, then changed
to close the interference - this was probably the WHALE.
0200 WHALE reported she was investigating contact to southwest and
would rendezvous at this position at 2300 tomorrow. They were
unable to raise the CABRILLA. A contact report from the HOE had
just been received, and this was possibly the contact the WHALE was
investigating. The HOE reported she was out of torpedoes so she
must have gotten in on the convoy.
0225 Relayed WHALE's message to CABRILLA by keying SJ, and notified
WHALE.
0533 Submerged.
1809 Surfaced.
1830 Exchanged calls with CABRILLA by SJ.

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2055 Exchanged recognition signals and calls with WHALE.

2140 Rendezvoused with WHALE.

2230 Received THREET, Lommie, MoMMlc., USN., 368 66 59, aboard via
rubber boat from WHALE. Received also submarine notices and instruction
we will need to get to SAIPAN.

2239 Set course for SAIPAN via convoy college safety lane at three
engine speed.

10 October, 1944

0528 Sighted BABUYAN ISLAND. Commenced passage of BALINTANG PASS.

0635 Sighted plane distant about six miles. Dove. Surfaced 25
minutes later.

0727 SD contact 6 miles. Dove. Surfaced 30 minutes later.

0840 SD contact 9 miles. Dove.

0851 Started to surface after all clear on SD when contact appeared
on screen at 10 miles. Went to 100 feet.

0902 Came to radar depth. We still had the contact at 9 miles. It
was steady at that range. Decided this was BALINTANG ISLAND although
it did not appear to the operator to be a definite land contact.
Visibility was very good.

0914 Surfaced.

1215 SD contact 12 miles. Dove. Surfaced 20 minutes later.

1410 SD contact 26 miles.

1415 SD contact 10 miles closed to 7 miles. Dove. Surfaced 20
minutes later.

1455 Picked up interference on SD.

11 October, 1944

0508 Made trim dive. Surfaced 20 minutes later.

0718 SD contact 10 miles. Dove.

0730 Two planes could be seen at extreme range.

0735 Surfaced.

0829 SD contact 16 miles opened out to 32 miles.

1045 Sighted a mine adrift (Lat. 21-45 N Long 128-38 E). Manned
20 m.m. guns. Destroyed mine by 20 m.m. fire. Took pictures. It was
quite an explosion.

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_12 October, 1944_

0930(I) Attempted to send ASPRO serial one giving ETA SAIPAN
rendozvous.

1200(I) Finally managed to obtain a receipt for our message.

1210(I) Sighted plane distant about 7 miles. Dove. Surfaced
12 minutes later. This contact was identified as a CATALINA.
Continued to have SD interference for the next hour.

_13 October, 1944_

0520 Sighted large mine (Lat.18-30 N Long. 139-58E). Attempted
to destroy the mine by 20 m.m. and 30 cal. fire. Several hits were
observed and close inspection revealed that hits had been scored.
The mine did not have contact horns. We put enough holes in it.
The mine should sink.

0749 SD contact 8 miles closed to 4 miles. Pulled a flare and dove.

0803 Surfaced.

0939 Sighted friendly submarine on opposite course. This was
undoubtedly the BLACKFIN. We were too far away for visual commun-
ications and they did not man their SJ.

_14 October, 1944_

0200(K) Sent ASPRO serial two giving ETA at rendezvous and requesting
entry instructions.

0800(K) Received message from C.T.G. 17.7 on 355 kcs to remain at
rendezvous and await escort.

Sighted numerous friendly planes throughout the day. Two
planes kept us company most of the time.

1325 (K) Made contact with escort and exchanged signals with PGM
9. Headed for TANAPAG HARBOR, SAIPAN.

1710 (K) Moored alongside U.S.S. FULTON, TANAPAG HARBOR, SAIPAN.

Started taking on diesel fuel, received 29,660 gallons
diesel fuel, four Mark 23 torpedoes and some provisions.

Transferred THREET, Lemmie, 368 66 59, MoMMlc.,(T), USN.,
to U.S.S. FULTON for medical treatment and disposition, transportation
completed.

Transferred RIO N, Paul L., 723 40 16, Slc.(TM)V-6,USNR., to
U.S.S. FULTON for medical treatment and disposition.

Received TAITANO, Antonio C., 421 04 55, Cklc., USN., for
transportation to Submarine Division 242.
- 20 -

— page 171 —
CONFIDENTIAL
Ensign William H. GOSSARD, D-V(G), U.S.N.R., reported aboard
for duty from Submarine Division EIGHTY TWO in accordance with
orders of Commander Task Group 17.7, serial 18 of 15 Oct. 1944.

16 October, 1944
0800(K) Underway from alongside U.S.S. FULTON.
0833(K) Joined escort PC 582 outside net. Set course for
bombing restriction lane.
Sighted numerous friendly planes throughout the day.
1253(K) Made trim dive.
1301(K) Surfaced.
1330(K) Escort departed. Set course for PEARL HARBOR, T.H. in
bombing restriction lane.

17 October, 1944
0931(K) Sighted plane, identified as PBY, distant 10 miles.
1327(K) Sighted plane, identified as PBM, distant 10 miles.
1409(K) Made trim and training dive. Surfaced 20 minutes later.
2315 (K) Exchanged recognition signals by SJ with U.S.S. HADDOCK.

18-25 October, 1944
Enroute PEARL HARBOR, T.H., made daily dives; conducted
training.

18 October, 1944
1630 (K) Sighted friendly submarine on opposite course. Exchanged
calls with U.S.S. ATULE. Another friendly submarine was at too
great a range for visual communication.

21 October, 1944
Crossed International date line. Gained a day.

- 21 -

— page 172 —
C O N F I D E N T I A L

25 October, 1944

0320 (VW) Exchanged recognition signals and calls with
CABRILLA by SJ. We have had her radar interference most
of the night.

0645 (VW) Rendezvoused with escort PC 579. Set course to
intercept CABRILLA.

0820 (VW) Made contact with CABRILLA. Set course for PEARL
HARBOR, T.H.

Had numerous friendly plane contacts during morning.

1340 (VW) Moored Submarine Base, PEARL HARBOR, T.H.

- 22 -

— page 173 —
C-O-N-F-I-D-E-N-T-I-A-L

(C) WEATHER
No unusual weather conditions were encountered. Skies were
generally partially cloudy but stars were generally available. During
the period 4 October to 9 October heavy seas and a strong north-
easterly wind prevailed off the northern coast of LUZON.

(D) TIDAL INFORMATION
Tides and currents were as indicated in pilots and tables. A
fairly uniform northerly set of about one knot was encountered off
the west coast of LUZON.

(E) NAVIGATIONAL AIDS
No navigational aids were sighted.

(F) SHIP CONTACTS (SEPARATE PAGE)

(G) AIRCRAFT CONTACTS (SEPARATE PAGE)

(H) ATTACK DATA (SEPARATE PAGE)

(I) MINES
A floating mine was encountered in Lat. 20-45 N Long 128-38 E
on 11 October and was exploded with 20 m.m. fire. It is not known
whether this was a loose anchored mine or a floater. Another mine
was encountered on 13 October in Lat 18-30 N Long 139-58 E.
Numerous hits were scored with 20 m.m. and 30 cal. fire puncturing
the casing. It did not explode nor sink during the time under
observation.

- 23 -

— page 174 —
(F) SHIP CONTACTS
No. | Time | Date | Lat. | Long. | Type(s) | Initial Range | Est. Course and Speed | How Con-tacted | Remarks
1 | 0604 | 9/20/44 | 6-30 S | 120-44 E | Sailboat | 16000 yds | 160 | 3 kts | Periscope
2 | 1643 | 9/20 | 6-05 S | 119-12 E | Sailboat | 16000 yds | 160 | 3 kts | Lookout
3 | 0830 | 9/23 | 7-29 N | 120-30 E | Sailboat | 8 miles | Undetermined | Lookout
4 | 0911 | 9/23 | 7-36 N | 120-32 E | 2 Sailboats | 8 miles | Undetermined | Lookout
5 | 1427 | 9/23 | 8-19 N | 120-56 E | Sailboat | 8 miles | Undetermined | Lookout
6 | 2150 | 9/24 | 13-26 N | 118-40 E | Hospital Ship | 15,700 yds | 213 | 9.5 kts | SJ Radar
7 | 2215 | 9/24 | 16-47 N | 119-07 E | Patrol Boat | 7 miles | Various | Lookout
8 | 0943 | 9/28 | 17-03 N | 119-07 E | 7 Trawlers | 10000 yds | 180 | 5 kts | Periscope
9 | 1025 | 9/30 | 17-03 N | 120-19 E | Convoy of 7 AK & AO plus escort | 15000 yds [HANDWRITTEN: est] | 180 | 7 kts | Sighted Smoke | Torpedo Attack No. 1
10 | 0935 | 9/30 | 17-36 N | 120-21 E | 3 sampans | 9000 yds | [HANDWRITTEN: 060] | 4 kts | Periscope
11 | 1232 | 10/1 | 17-34 N | 120-13 E | Convoy 1 AK, 1 AO, 1 trawler | 14000 yds | Northerly | 6.5 kts | Periscope | Hugging coast
12 | 0538 | 10/2 | 18-11 N | 120-19 E | Same as No. 11 | 10,000 yds | Northerly | 6.5 kts | Lookout | Hugging coast - Torpedo Attack No. 2 and 3.
13 | 0801 | 10/2 | 18-22 N | 120-23 E | 3 sea trucks | 90000 yds | Southerly | 6.5 kts | Periscope
14 | 0525 | 10/2 | 17-52 N | 120-31 E | Crippled AK | 18000 yds | Drifting | Unknown | SJ Radar | Torpedo Attack No. 4a & 4b
15 | 0950 | 10/5 | 17-39 N | 120-13 E | Trawler | 10000 yds | Various | Unknown | Periscope

- 24 -

— page 175 —
CONFIDENTIAL
(F) SHIP CONTACTS

No. | Time | Date | Lat | Long | Type(s) | Initial Range | Estimated Course & Speed | How Contacted | Remarks
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
16 | 0442 | 10/6 | 16-59N | 120-15E | Patrol Boat | 10000 yds | Various | SJ radar |
17 | 0650 | 10/6 | 16-53N | 120-19E | Convoy of about: | 14,000 yds: [HANDWRITTEN: 8 km] | 055 T | Periscope | Torpedo Attack No. 5
   |      |      |       |         | 12 ships-AO, AK. |                       | 8 knots |             |
18 | 0310 | 10/7 | 17-48N | 120-04E | Convoy of about: | About 6 AK - 10 miles | 270 T | Periscope | No escorts
   |      |      |       |         | 12 ships-AO, AK. |                       | 8 knots |             | evident-possibly
   |      |      |       |         | AP plus escorts. |                       |         |             | same as No.18
19 | 1607 | 10/7 | 17-48N | 119-30E | | | | |
20 | 0310 | 10/7 | 17-48N | 120-04E | | | | |
21 | 1607 | 10/7 | 17-48N | 119-30E | | | | |

- 25 -

— page 176 —
C O N F I D E N T I A L
(G) AIRCRAFT CONTACTS

| No. | Time | Date | Lat. | Long. | Est. Range | Est. Course | Type(s) | How Contacted | Remarks |
|---|
| 1 | 1400 | 9/18 | 1-18 S | 127-54 E | 10 miles | Unknown | Unknown | SD radar | Patrolling |
| 2 | 1558 | 9/18 | 9-03S | 127-40E | 10 miles | Unknown | Unknown | SD radar | Patrolling |
| 3 | 1552 | 9/19 | 6-15S | 127-40E | 9 miles | Unknown | Unknown | SD radar | Patrolling |
| 4 | 0639 | 9/20 | 3-16 S | 119-29E | 6 miles | Unknown | Unknown | SD radar | Patrolling |
| 5 | 0750 | 9/21 | 2-35 S | 118-25 E | 6 miles | Unknown | Unknown | SD radar | Patrolling |
| 6 | 1149 | 9/21 | 2-07S | 118-33E | 12 miles | Unknown | Unknown | SD radar | Patrolling |
| 7 | 1407 | 9/21 | 1-34 S | 118-35 E | 12 miles | Unknown | Unknown | SD radar | Patrolling |
| 8 | 1232 | 9/22 | 1-34 S | 119-51 E | 16 miles | Unknown | Unknown | SD radar | Patrolling |
| 9 | 1235 | 9/22 | 2-38 N | 119-49 E | 27,30 miles | Unknown | Unknown | SD radar | Patrolling |
| 10 | 1544 | 9/22 | 3-20N | 119-49E | 22 miles | Unknown | Unknown | SD radar | Patrolling |
| 11 | 1550 | 9/24 | 11-32N | 121-11E | 15 miles | 270 T | Unknown | Lookout | Patrolling |
| 12 | 0704 | 9/24 | 11-37N | 121-00E | 12 miles | 6 | Unknown | SD radar | Patrolling |
| 13 | 0836 | 9/24 | 12-50N | 120-27E | 26 miles | Unknown | Unknown | SD radar | Patrolling |
| 14 | 1455 | 9/26 | 17-52N | 118-26E | 7 miles | 180 T | 2 | Lookout | Patrolling |
| 15 | 0742 | 9/27 | 18-02 N | 118-37E | 8 miles | 180 T | Sight | Lookout | Patrolling |

- 26 -

— page 177 —
CONFIDENTIAL

(G) AIRCRAFT CONTACTS

No. | Time | Date | Lat. | Long. | Type(s) | Initial Range | Est. Course | How Contacted | Remarks
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
16 | 0925 | 9/29 | 17-00N | 119-34E | Unknown | 6 miles | 000 | Periscope | Patrolling
17 | 0607 | 9/30 | 17-02N | 120-10E | Unknown | 3 miles | --- | Periscope | Patrolling
18 | 1120 | 9/30 | 17-00N | 120-22E | Unknown | 2 | --- | Periscope | Escorting Convoy
19 | 9730 | 9/30 | 17-00N | 120-26E | Unknown | 0 | --- | Periscope | Escorting Convoy
20 | 1224 | 9/30 | 16-58N | 120-22E | Unknown | 4 miles | Various | Periscope | Escorting Convoy
21 | 1355 | 9/30 | 16-58N | 120-22E | Unknown | 3 | Various | Periscope | Escorting Convoy
22 | 1420 | 9/30 | 16-59N | 120-08E | Unknown | 5 | Various | Periscope | Escorting Convoy
23 | 1535 | 9/30 | 16-51N | 120-06E | Unknown | 6 miles | Various | Periscope | Escorting Convoy
24 | 2357 | 10/1 | 17-23N | 119-40E | Unknown | 5000 yds | Unknown | SJ radar | Patrolling
25 | 0326 | 10/1 | 17-39N | 119-57E | Unknown | 6000 yds | Unknown | SJ radar | Patrolling
26 | 0545 | 10/1 | 17-39N | 120-06E | Topsy | 8 miles | 180 T | Periscope | Patrolling
27 | 1430 | 10/1 | 17-32 N | 120-22E | Pete | 2 miles | Various | Periscope | Hunting
28 | 0801 | 10/2 | 18-22N | 120-31E | Betty | 3 miles | Various | Periscope | Escorting Convoy

- 27 -

— page 178 —
CONFIDENTIAL
(G) AIRCRAFT CONTACTS

| No. | Date | Time | Lat. | Long. | Type(s) | Initial Range | Est. Course | How Contacted | Remarks |
|---|
| 29 | 10/2 | 0930 | 18-25N | 119-33E | Betty | 10 miles | 180 | Lookout | Escorting Convoy |
| 30 | 10/3 | 0723 | 17-52N | 119-51E | Unknown | 5000 yds | Unknown | SJ radar | Patrolling |
| 31 | 10/3 | 2035 | 17-50N | 119-20E | Unknown | 26 miles | Unknown | 3D radar | Patrolling |
| 32 | 10/4 | 0739 | 18-20N | 119-39E | Unknown | 6 miles | 180 | Periscope | Patrolling |
| 33 | 10/5 | 0825 | 17-40N | 120-13E | Topsy | 7 miles | 180 | Periscope | Transit |
| 34 | 10/5 | 0903 | 17-38N | 120-14E | Nell | 2 | Various | Periscope | Transit |
| 35 | 10/5 | 1015 | 17-36N | 120-12E | Mary | 5 miles | Various | Periscope | Patrolling |
| 36 | 10/5 | 1214 | 17-35N | 120-17E | Mavis | 4 miles | Various | Periscope | Patrolling |
| 37 | 10/5 | 1238 | 17-28N | 120-20E | Mavis | 4 miles | Various | Periscope | Patrolling |
| 38 | 10/5 | 1458 | 17-28N | 120-20E | Unknown | 8 miles | Various | Periscope | Patrolling |
| 39 | 10/5 | 1246 | 17-28N | 120-20E | Unknown | 8 miles | Various | Periscope | Patrolling |
| 40 | 10/5 | 1458 | 17-29N | 120-20E | Pete | 1/2 miles | 000 | Periscope | Patrolling |
| 41 | 10/6 | 1235 | 17-29N | 120-19E | Mavis | 4 miles | 120 | Periscope | Patrolling |
| 42 | 10/6 | 0650 | 16-50N | 120-14E | Dave | 5 miles | 120 | Periscope | Patrolling |
| 43 | 10/6 | 1027 | 16-50N | 120-03E | Holt | 8 miles | Various | Periscope | Hunting |

- 28 -

— page 179 —
(G) CONFIDENTIAL
(G) AIRCRAFT CONTACTS

No. | Time | Date | Lat. | Long. | Type(s) | Initial Range | Est. Course | How Contacted | Remarks
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
44 | 0718 | 10/8 | 19-03N | 118-46E | Unknown | 13 miles | | SD radar | Patrolling
45 | 0736 | 10/8 | 19-03N | 118-46E | Unknown | 10 miles | | SD radar | Patrolling
46 | 1220 | 10/8 | 19-12N | 119-13E | Unknown | 10 miles | | SD radar | Patrolling
47 | 1304 | 10/8 | 19-47 N | 119-17E | Unknown | 12 miles | | SD radar | Patrolling
48 | 1342 | 10/8 | 19-52N | 119-21E | Mavis | 8 miles | | Lookout | Patrolling
49 | 1520 | 10/8 | 20-02 N | 119-23E | Dave | 6 miles | | Lookout | Patrolling
50 | 0635 | 10/10 | 19-58N | 121-38E | Various | 6 miles | | Lookout | Patrolling
51 | 0727 | 10/10 | 19-58N | 121-48E | Unknown | 6 miles | | SD radar | Patrolling
52 | 1215 | 10/10 | 20-30N | 122-40E | Unknown | 12 miles | | SD radar | Patrolling
53 | 1415 | 10/10 | 20-45N | 123-10E | Unknown | 10 miles | | SD radar | Patrolling
54 | 0718 | 10/11 | 19-47N | 133-48E | Unknown | 10 miles | | SD radar | Patrolling

- 29 -

— page 180 —
C O N F I D E N T I A L
(G) AIRCRAFT CONTACTS

| No. | Time | Date | Lat. | Long. | Type(s) | Initial Range | Est. Course | How Contacted | Remarks |
|-----|------|------||||||||
| 55  | 10/11| 0829 | 19-43N   | 133-58E   | Unknown   | 16 miles      | UNKNOWN       | SD radar      |         |
| 56  | 10/12| 1210 | 19-35N   | 135-00E   | PBY       | 7 miles       | 340           | Lookout       |         |
| 57  | 10/13| 0749 | 18-07 N  | 140-25E   | Unknown   | 8 miles       | Unkn'wn       | SD radar      |         |

- 30 -

— page 182 —
C-O-N-F-I-D-E-N-T-I-A-L
(H) ATTACK DATA
U.S.S. ASPRO (SS309)
TIME: 0846 DATE 2 October, 1944 L.T. 18-25 N LONG 120-32E
TORPEDO ATTACK NO. 2 PATROL NO. 5

DESCRIPTION: One medium tanker and one medium engine aft AK with
air cover were northbound hugging the coast of LUZON and remain-
ing inside the ten fathom curve. There was a small trawler or
diesel sampan leading but apparently it was not equipped for
escort work.

SHIP SUNK: One medium tanker (EU) - estimated tonnage 5000-6000 tons

DAMAGE DETERMINED BY: Observed ship through the periscope listed
to starboard, the bow in the air at an angle of 60-70 degrees,
and the remainder of the ship under. Smoke was pouring out. On
the next observation the ship had sunk. Sound reported the
characteristic breaking up noises for 15-20 minutes.

TARGET DRAFT 20 feet. COURSE 335 SPEED 7 RANGE 2600 yds

OWN SHIP DATA

SPEED 3 knots OWN COURSE 035 DEPTH 62 ft. ANGLE - ZERO

FIRE CONTROL AND TORPEDO DATA

TYPE ATTACK: Attack was made at periscope depth after a long
chase at 8 knots to close the track.

| | 1 | 2 | 3 | 4 |
|:|:------|:------|:------|:------|
| Tubes Fired | 1 | 2 | 3 | 4 |
| Track Angle | 121 P | 120 P | 120 P | 123P |
| Gyro Angle | 1 L | ½ L | 0 | 3½L |
| Depth Set | 6 | 6 | 6 | 6 |
| Hit or Miss | Hit | Hit | Miss | Hit |
| Erratic | No | No | No | No |
| Mark Torpedo | 23-0 | 23-0 | 23-0 | 23-0 |
| Serial No | 49245 | 50019 | 50277 | 41040 |
| Mark Exploder | 6-5 | 6-5 | 6-5 | 6-5 |
| Serial No | 25865 | 28911 | 25946 | 25313 |
| Mark Warhead | 16-1 | 16-1 | 16-1 | 16-1 |
| Serial No | 4133 | 17405 | 17119 | 3567 |
| Firing Interval | 0 | 7 | 8 | 7 |
| Type Spread | 1½L | 1½R | 1½R | 1½L |
| See Conditions | - - - - MODERATE - - - - |
| Overhaul Activity | S/M Repair Unit, Navy No. 137 |

- 32 -

— page 183 —
CONFIDENTIAL

(H) ATTACK DATA

U.S.S. ASTRO (SS309) TORPEDO ATTACK No. 3 PATROL No. 5

TIME 0955 DATE 2 October,1944 LAT. 18-25N LONG 120-32 E

DESCRIPTION: The medium AK described in attack No. 2 returned to
pick up survivors. She was stopped and lying to with a small
sampan alongside. There was a plane circling overhead.

SHIP DIMENSIONS: One medium AK (EU) - engine aft AK, estimated
tonnage 5000-6000 tons.

DAMAGE DETERMINED BY: Observed ship down by the stern. The after
50-75 feet of the ship had sagged about 15-20 feet.

TARGET DRAFT 20 feet COURSE: 205 TARGET SPEED 0 RANGE 1700

OWN SHIP DATA

SPEED 3 COURSE 260 DEPTH 62 ft. ANGLE - ZERO

FIRE CONTROL AND TORPEDO DATA

TYPE ATTACK: Periscope approach following attack No. 2

Tubes Fired | 7 | 8 | 9
|---|---|---
Track Angle | 44 S | 46 S | 43 S
Gyro Angle | 12 L | 10 L | 13 L
Depth Set | 6 | 6 | 6
Hit or Miss | Hit | Miss | Hit
Erratic | No | No | No
Mark Torpedo | 23-0 | 23-0 | 23-0
Serial No. | 49609 | 49489 | 49513
Mark Exploder | 6-5 | 6-5 | 6-5
Serial No. | 25890 | 25874 | 25868
Mark Warhead | 16-1 | 16-1 | 16-1
Serial No. | 17027 | 13685 | 34239
Firing Interval | 0 | 7 | 7
Type Spread | 0 | 1 ½ R | 1 ½ L
Sea Conditions | - - - - - - MODERATE - - - - - -
Overhaul Activity | S/M Repair Unit, Navy No. 137

- 33 -

— page 184 —
C-O-N-F-I-D-E-N-T-I-A-L

(H) ATTACK DATA

U.S.S. ASPRO (SS309)
                                                                TORPEDO
                                                                ATTACK No. 4 a           PATROL No. 5
TIME 0928           DATE 3 Oct. 1944 LAT. 17-56 N LONG 119-52 E

                                                                TORPEDO ATTACK 4 b

TIME 0955           DATE 3 Oct. 1944 LAT. 17-56 N LONG 119-52E

DESCRIPTION: The AK damaged in attack No. 3 was contacted by
radar at dawn. The ship was adrift, looked deserted, and had
an anchor chain out. The seas were rough. It is believed
the damaged ship dragged anchor during the night.

SHIP SUNK: One medium AK (EU) - engine aft AK, estimated tonnage
           5000-6000 tons.

DAMAGE DETERMINED BY: Observed ship sink through periscope.
                      Took periscope pictures of the ship sinking.

TORPEDO ATTACK 4 a TARGET DRAFT 20 ft. COURSE 250 TARGET SPEED 1.5
                     RANGE 2200 yards.

TORPEDO ATTACK 4 b TARGET DRAFT 20 ft. COURSE 248 TARGET SPEED 1.5
                     RANGE 1400 yards

                                                                OWN SHIP DATA

TORPEDO ATTACK NO. 4 a SPEED 4 COURSE 340 DEPTH 62 ft. ANGLE-0

TORPEDO ATTACK NO. 4 b SPEED 3.8 COURSE 170 DEPTH 62 ft. ANGLE-0

                                                                FIRE CONTROL AND TORPEDO DATA

TYPE ATTACK: Periscope depth approach after a surface end round
to reach position ahead.

                                                                - 34 -

— page 185 —
CONFIDENTIAL
(H) ATTACK DATA

TORPEDO ATTACK NO. 4 a

Tubes Fired | 7 | 8
Track Angle | 92 S | 93 S
Gyro Angle | 3½ R | 4½R
Depth Set | 8 | 10
Hit or Miss | Hit | Possible Hit
Erratic | No | No
Mark Torpedo | 23-0 | 23-0
Serial No. | 49191 | 49973
Mark Exploder | 6-5 | 6-5
Serial No. | 25834 | 25902
Mark Warhead | 16-1 | 16-1
Serial No. | 34256 | 16398
Firing Interval | 0 | 14
Type Spread | --- POINT OF AIM ---
Sea Conditions | --- HEAVY SEAS ---
OVERHAUL ACTIVITY | S/M Repair Unit, Navy No. 137

TORPEDO ATTACK No. 4 b

Tubes Fired | 1 | 2
Track Angle | 101 S | 104 S
Gyro Angle | 0 | 2½ R
Power | High | ---
Depth Set | 8 | 8
Hit or Miss | Hit | Miss
Erratic | No | No
Mark Torpedo | 14-34 | 23-0
Serial No. | 25840 | 50193
Mark Exploder | 6-5 | 6-5
Serial No. | 21782 | 25912
Mark Warhead | 16 (TPX) | 16-1
Serial No. | 6094 | 17352
Firing Interval | 0 | 2 m. - 16 s.
Type Spread | --- POINT OF AIM ---
Sea Conditions | --- HEAVY SEAS ---
OVERHAUL ACTIVITY | S/M Repair Unit, Navy No. 137

- 35 -

— page 186 —
CONFIDENTIAL
(H) ATTACK DATA
U.S. ASPRO (SS309) TORPEDO ATTACK NO.5 PATROL NO.5
TIME: 0830 DATE: 6 Oct., 1944 LAT.16-53N LONG 120-18E

DESCRIPTION: Large convoy of 12-14 marus with air and surface
escorts following close to the coast of LUZON, northbound. The
exact disposition of the convoy could never be determined, but
it is believed they were attempting to stay in two columns.
Their zig zagging consisted of ship turn movements to open
or close the beach - the remainder of the time they stayed on
the base course.

SHIP DAMAGED OR PROBABLY SUNK: One large tanker (EU) - estimated
tonnage 8000-10000 tons.

DAMAGE DETERMINED BY: One definite torpedo explosion heard through
the hull. One loud rumbling explosion heard just before the
depth charging. Later at periscope depth the tanker could
not be seen with the convoy

TARGET DRAFT: 26 feet COURSE: 010 SPEED 7 RANGE 1500 yds.

OWN SHIP DATA
SPEED 3 COURSE 270 DEPTH 63 ft. ANGLE - ZERO

FIRE CONTROL AND TORPEDO DATA
TYPE ATTACK: A periscope depth attack was made. Most of the
approach was conducted at depths below periscope depth. This
procedure was necessary to evade depth charging of one escort
and to avoid plane detection while running at high submerged
speeds.

| | 8 | 9 | 10 |
|---|---|---|---|
| TUBES FIRED | | | |
| TRACK ANGLE | 142 P | 143 P | 144 P |
| GYRO ANGLE | 43 L | 42½ L | 42 L |
| DEPTH SET | 6 | 6 | 6 |
| HIT OR MISS | HIT | Miss | Miss |
| ERRATIC | No | No | No |
| MARK TORPEDO | 23-0 | 23-0 | 23-0 |
| SERIAL NO. | 49977 | 49346 | 50259 |
| MARK EXPLODER | 6-5 | 6-5 | 6-5 |
| SERIAL NO. | 25910 | 25870 | 25921 |
| MARK WARHEAD | 16-1 | 16-1 | 16-1 |
| SERIAL NO. | 17391 | 12886 | 17480 |
| FIRING INTERVAL | 0 | 10 | 8 |
| TYPE SPREAD | 0 | 2 L | 2 R |
| SEA CONDITIONS | - - - - - - - MODERATE - - - - - - - |
| OVERHAUL ACTIVITY | S/M Repair Unit, Navy No. 137 |

- 36 -

— page 187 —
CONFIDENTIAL
(H) ATTACK DATA
U.S.S. ASPRO (SS309) TORPEDO ATTACK NO. 6 PATROL NO. 5
TIME: 0456 DATE: 7 October,1944 LAT.17-54 N LONG 119-57 E

DESCRIPTION: Convoy of an unknown number of ships. There were
apparently two groups of 5-6 ships in each group. There were
the usual escorts but no air cover. This convoy was contacted
by the HOE at night and all three submarines of the wolfpack
made successful attacks. Visibility was good with the moon
directly overhead. Contact was made approximately three hours
before daybreak.

SHIP SUNK: One large AK (EU) - large well deck type with two
or more goal post masts, estimated tonnage 7000-8000 tons.

DAMAGE DETERMINED BY: Observed ship almost immediately after
the three timed hits. The freighter was down by the stern,
the bow at an angle of 40 degrees, and the water up to the
midship deckhouse. The ship was smoking heavily. Sound
reported a loud heavy explosion on the target. When the
commanding officer swung the periscope to the targets
bearing, following this report, the ship had already sunk.

TARGET DRAFT: 26 ft. COURSE: 298 SPEED 9 RANGE 2600

OWN SHIP DATA
COURSE 000 DEPTH 53 ANGLE 3-4° DOWN.

FIRE CONTROL AND TORPEDO DATA
TYPE ATTACK: A surface end around was made. ASPRO went to radar
depth when the range was 4600 yards and ordered periscope depth
at a range of 3000 yards. Actually the torpedoes were fired
before reaching periscope depth.

- 37 -

— page 189 —
C O N F I D E N T I A L

(K) MAJOR DEFECTS AND DAMAGE

1. Starboard main motors. On the ASPRO's fourth patrol difficulty
was experienced in balancing the load between No. 1 and No. 3 main
main motors. Severe sparking burned about 12 brush holders. Upon
removing the forward end of No. 3 motor casing one lead from the
compensating field shunt was found lying disconnected in the bottom
of the casing. Replacing the lead partially rectified the trouble at
that time. Intermittently throughout the patrol No. 3 motor had to be
disconnected and compensating field shunt adjusted in order to reduce
sparking or equalize the load. No position could be found to eliminate
sparking at all loads.

The cause of the unbalance could not be determined during
the last refit. The replacement of the burned brush holders was
accomplished.

Operation on this patrol has continued to be unsatisfactory
At two engine speed, the motors were capable of being very nearly
brought into balance by regulating the flow of circulating water to
the motors. At three engine speed an unbalance of 450-800 amps
exists. No. 1 motor, now attempts to hog the load, where previously,
i.e. on the fourth patrol, No. 3 motor took most of the load. At four
engine speed the unbalance is even higher. Limited operation at
four engine speed on this patrol resulted in insufficient data, but
it is believed that the motors could not carry four engine load
without overheating.

While operating at three engine speed on 18 October the motors
changed within two hours from a load difference of 450 amps to a
difference of 1200 amps, No. 1 motor hogging the load. The load
difference suddenly increased to 2000 amps and finally No. 3 motor
took no load. At two engine speed the load differential continued
high and No. 1 motor commenced sparking. Attempts to adjust the
compensating field shunt were unsuccessful. Finally, No. 1 motor
was disconnected electrically.

2. JK/QC and QB Sound Heads - Both sound heads were rendered
inoperative due to grounding on 1 October. The extent of damage
has not been determined.

3. P.P.I. - The PPI went out when transformer T ( ) 1 failed on
22 September. Since no spare is carried this valuable piece of
equipment remained inoperative throughout the patrol. It is
recommended that this transformer be included in the aboard ship
spares.

4. SJ Motor Generator - This unit continues to be unsatisfactory
for its intended use. It is incapable of supplying a continuous
voltage to operate the SJ radar.

5. Target Bearing Transmitters - The after T.B.T. flooded
when at deep submergence after our departure on patrol. Repeated
efforts during the training period to make this equipment tight
were unsuccessful. Ship's force attempted repairs while at DARWIN
and later while enroute to the area. Finally the cable from the TBT
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— page 190 —
C-O-N-F-I-D-E-N-T-I-A-L
to the conning tower became grounded to such an extent the T.B.T.
was rendered completely inoperative.

The forward T.B.T. was jarred out of alignment during
depth charging on 6 October.

(L) RADIO

No casualties were experienced with the radio gear.
Reception in the area was generally satisfactory. VHM was
the best shore station for ship-shore traffic in the area. VIXO
was hard to get. South of DARWIN however VIXO was strong though
JAP interference was too. On one occasion a powerful station
answered VIXO with our call.

On the new HAIKU frequencies, the 9515 kc frequency was
useless due to interference from a station "Radio Tokyo" from
1200 to 1700 G.C.T. 9250 kcs was a good frequency on VIXO
however.

(M) RADAR

The SJ radar performance was satisfactory.

The PPI went out on 22 September when transformer T ( ) 1
(KS8886) developed a low ground reading in the 5600 V secondary
winding. The resultant high current in the primary blew the
AC fuses in the main control unit. Isolating the transformer
permitted operation of the SJ. The PPI was out of commission
for the remainder of the run - no spare transformer is carried.

On the SD one of the contact points on the keying relay
broke off so recourse was had to the variac switch for interrupting
the transmitted signal. Performance was above the standard of
previous runs - more planes were picked up at generally greater
ranges although the initial range of plane contacts varied
between about 6 and 30 miles.

(N) SOUND GEAR AND SOUND CONDITIONS

Both sound heads were put out of commission by grounding on
1 October leaving the JP-1 to carry the load. Considering the
remoteness of the gear from the conning tower it worked well enough.

A vacuum tube in the JP for which no replacement was on hand
was jarred loose by depth charges. Investigation showed that the
glass bulb was secured to the base plug with glue. It was glued
together again and performed satisfactorily. It is recommended
that the use of some more rugged substance as a cohesive agent
be required in these tubes.

Sound conditions in the area of the South China Sea immediately
west of northern LUZON were mediocre.

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— page 191 —
C O N F I D E N T I A L

(O) DENSITY LAYERS

Density layers found are as given below:

Card | Layer | Temp. | Gradient | Depth at | Date | LAT
No. | Depth | Layer | | Deepest | Time | LONG
| | Depth | | Submergence | GCT |
1 | 120' | 83° | 9° | 420' | 9/30 | 17-02N
| | | | | 0500 | 120-25 E
2 | 180' | 83° | 10° | 385' | 9/30 | 17-00 N
| | | | | 0940 | 119-25 E
3 | 200' | 84° | 10° | 390' | 10/1 | 17-31 N
| | | | | 0900 | 120-20 E
4 | 140' | 84° | 8° | 330' | 10/2 | 18-25 N
| | | | | 0200 | 120-30 E
5 | 100' | 84° | 11° | 350' | 10/5 | 16-53 N
| | | | | 2128 | 120-15 E
6 | 100' | 84° | 15° | 390' | 10/5 | 16-53 N
| | | | | 2231 | 120-14 E
7 | 120' | 84° | 7° | 300' | 10/6 | 17-05 N
| | | | | 0430 | 119-46 E

(P) Health Food and Habitability

The health of the crew was generally good. One case of
gonorrhea appeared which responded to sulfa treatment though less
rapidly than previous cases. Upon arrival at SAIPAN a tuberculosis
suspect was transferred to the FULTON. Positive diagnosis was not
determined by the doctors there but they were fairly certain that
it was tuberculosis.

There was nothing unusual about the food or habitability.
An air conditioning unit for the forward battery would improve
habitability but it is quite bearable as is. The assortment and
quality of stores available at Freemantle is not up to the standard
of Pearl but is satisfactory.

(Q) PERSONNEL

The performance of duty of all hands was commendable and the
state of training most satisfactory. The quiet, efficient, and
orderly manner orders were carried out and the general cond ct of
all hands during the g ounding on 1 October was gratifying and a
source of strength to the commanding officer.

Training of new men and training of less experienced men in
the duties and responsibilities of their rating continues to be
stressed. The more experienced men on board share with the officers
the responsibility of enlightening the new men. Two school periods
are held each day, and occasionally lectures on specialized subjects
are given by the officers. Every effort is made to make the training
program alive and interesting by introducing new ideas from time to
time. Upon departure from the area, the watches are rearranged to
give the "strikers" an opportunity to learn the duties required of
their rating. This is an excellent time to train controllermen,

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— page 192 —
C-O-N-F-I-D-E-N-T-I-A-L

manifold men, torpedomen, etc.

The personnel situation for the next patrol is not too
encouraging. Twenty-four men will be completing their fifth
straight patrol on the ASPRO. Many of this number are key men
but it is hoped that suitable replacements can be obtained from
the relief crew. Twenty to twenty five percent of the crew
have been transferred after each patrol; and, except in special
cases, men transferred had completed at least two patrols (excep-
tion - those transferred after the first patrol). The ASPRO has
had two unexpected refits at FREMANTLE, W.A. While these refits
have been desirable for their beneficial effect on morale they
have worked to a disadvantage as far as relief of the crew is
concerned. Men transferred to relief crews have in most cases been
lost to the ASPRO. To date ASPRO has received only 5 men who were
previously transferred with the expectation that they would be
returned.

No. of men qualified in submarines during run * 5
No. of men advanced in rating during run 11
No. of men on board not qualified in submarines 15
No. of men making their first patrol 12

* 2 runs required for qualification.

(R) MILES STEAMED - FUEL USED

FREMANTLE to AREA (Via DARWIN) 4348 miles 49050 gals.
In AREA 2192 miles 19390 gals.
AREA to PEARL (Via SAIPAN) 5033 miles 74370 gals.

(S) DURATION

Days enroute area 15
Days in area 13
Days enroute Pearl 18
Days submerged 10

(T) FACTORS OF ENDURANCE REMAINING

TORPEDOES FUEL PROVISIONS PERSONNEL
* 4 25700 30 15

Limiting factor this patrol was expenditure of all torpedoes

* 4 torpedoes and 29,665 gallons fuel were received from FULTON

(U) REMARKS

USE OF SJ FOR COMMUNICATIONS

The most satisfactory means our submarines have of establishing
their friendly character to one another is by using the keying
feature of the SJ transmitter to exchange recognition signals.

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— page 193 —
C-O-N-F-I-D-E-N-T-I-A-L

Even in daylight, communication by SJ is more efficient than by
visual methods. Difficulty has been experienced in attempting
to exchange recognition signals by this method by the failure of
a submarine to answer. It is recommended that a definite procedure
be followed by submarines when SJ interference appears on the
screen and until recognition signals have been exchanged. When
interference first is noted, a competent operator should attempt
to exchange recognition signals and calls. If, after a period
of five to ten minutes there has been no success, make repeated
attempts the first five minutes of each hour and half hour. It
is also suggested that submarines man the SJ for recognition
purposes in daytime on sight contact with other submarines -
friendly character can thus be established long before visual
methods of communications are possible.

The SJ should not be used for communication, after
exchange of recognition signals, except in emergencies. The
ASPRO and CABRILLA communicated successfully using the SJ, but
it was a mistake. The SJ was unnecessarily tied up for long
periods when it should have been employed for its intended
use.

WOLFPACK COMMUNICATIONS

The following comments on wolfpack communications are
given:

1. Voice radio was not reliable. There seems to be no
explanation for having satisfactory performance one night and
very unsatisfactory performance the next night. CW transmission
was
successfully employed when voice failed.

2. A permanent list of voice calls for all submarines
would be desirable. We did not know the special calls used
by WHITAKER'S wolfpack until they were transmitted in a
message to the BONEFISH.

3. The aircraft code is considered adequate for wolfpack
communications. However, any code message is difficult to
transmit and receive via voice communications. The primary
purpose of a voice circuit is to make possible rapid communic-
ations. This purpose is partially defeated when code messages
requiring the operator to pronounce each letter are transmitted.
One possible solution would be to have a number of plain
language phrases and expressions with unrelated meanings. A
table of such plain language expressions would not be very
long to accomodate all that submarines would have occasion to say
to each other in making a coordinated attack.

MAIN MOTORS

There has been one occasion of load unbalance between
No. 2 and No. 4 motors since ASPRO departure from SAIPAN.
Subsequent operation has been normal. However, it is an
indication that trouble may be expected with the port main
motors similar to that described under section K for the starboard

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— page 194 —
C-O-N-F-I-D-E-N-T-I-A-L

main motors.

The cause of the load unbalance between the main motors
must be discovered and the condition corrected. Present
operation of the main motors is considered unreliable.

- 44 -

— page 195 —
SUBMARINE DIVISION FORTY THREE.
Care of Fleet Post Office,
San Francisco, California.

FB5-43/A16-3
Serial: (1003) 27 October 1944

CONFIDENTIAL

FIRST ENDORSEMENT to
CO, USS ASPRO Conf. ltr.
SS309/Serial 017 dated
25 October 1944.

From: The Commander Submarine Division FORTY-THREE.
To : The Commander in Chief, UNITED STATES FLEET.

Via: (1) The Commander Submarine Squadron FOUR.
(2) The Commander Submarine Force, PACIFIC FLEET.
(3) The Commander in Chief, U.S. PACIFIC FLEET.

Subject: U.S.S. ASPRO (SS309) - Report of Fifth War Patrol,
Comments on.

1. The Fifth War Patrol of the U.S.S. ASPRO was conducted in
the South China Sea. Part of the time was spent as a unit of a coordinated
attack group with the CABRILLA and HOE. The patrol was of forty-six days
duration, fourteen of which were spent in the assigned area. The patrol
was most aggressively conducted. Attacks were pressed home in spite of
shoal water which caused groundings and loss of keel sound heads, almost
constant air coverage, and numerous escorts and patrol vessels. Fifty-
seven aircraft contacts were obtained and six torpedo attacks, two on the
same target were carried out.

2. Torpedo Attack No. 1 during daylight, 30 September, off the
coast of Luzon, a southbound convoy of seven or eight ships, with four
escorts and three planes, was attacked with six mark 23 torpedoes, fired
from the bow tubes. The target was an unidentified large AK, with a
second freighter overlapping. First torpedo was fired on a 98° starboard
track, 1700 yard run, with 11½° left gyro. Two close escorts prevented
observation of hits, but timed explosions were heard at 1 minute, 39 seconds
and 1 minute, 49 seconds after the first torpedo was fired. Breaking up
noises were heard for 15-20 minutes over the sound gear while escorts dropped
forty-three depth charges. Later observation of the convoy revealed the
tops and smoke of only six remaining ships.

Torpedo Attack No. 2 - In a submerged attack on 2 October four mark
23 torpedoes were fired at a medium AO, torpedo run 2700 yards, 120° port
track angle. This tanker and an engine aft freighter had been sighted
the day before, at which time an attack was frustrated by several groundings.
In order to attain a good firing position, it was necessary to make a long
run toward the coast at eight knots as the target was proceeding within
the ten fathom curve off CAPE BOJEADOR. The only surface escort was a
single sampan or trawler. The Commanding Officer saw the target sink about
three minutes after target was hit by three unobserved timed hits. Two
aircraft bombs were dropped after the attack.

- 1 -

— page 196 —
FB5-43/A16-3
Serial (1003)

CONFIDENTIAL

FIRST ENDORSEMENT to
CO, USS ASPRO Conf. 1
SS309/Serial 017 dated
25 October 1944.

Subject: U.S.S. ASPRO (SS309) - Report of Fifth War
Comments on.

SUBMARINE DIVISION FORTY THREE

Care of Fleet Post Office,
San Francisco, California.

27 October 1944.

Torpedo Attack No. 3 - About an hour and ten minutes after attack
No. 2, three mark 23 torpedoes were fired at the engine aft freighter
which was in company with the tanker. Torpedo run was 1800 yards; track
angle 44 degrees starboard. The freighter was stopped while picking up
survivors; the small trawler or sampan was alongside; and a plane was seen
circling the target at the time of firing. Aircraft bombs forced the
ASPRO to go to 150 feet. Two timed torpedo explosions were heard at
1 minute and 24 seconds and 1 minute and 57 seconds after firing the
first torpedo. Fifteen minutes after firing the freighter was observed
to be damaged as it was slightly down by the stern. When the target got
underway further attacks were hindered by the anti-submarine air patrol
and a very low battery.

Torpedo Attack No. 4a - 4b - After an initial contact by radar at
19,000 yards and an end around run, a submerged attack was made on the
freighter damaged the day before in attack No. 3. The target tracked at
1.5 knots when two mark 23 torpedoes were fired from the stern tubes, run
2200 yards. One unobserved timed hit was recorded. Twenty-seven minutes
later two more torpedoes were fired from the bow tubes, run 1400 yards,
and one hit was observed in the MOT. Five or six minutes later the ship
was seen to sink, stern first.

Torpedo Attack No. 5 - After a determined submerged approach, where
escorts and aircraft were very much in evidence, the ASPRO fired their
last three stern torpedoes at a large AO which was one ship of a 12-14
ship convoy. Torpedoes were fired on a 142-144 degree port track, run
about 1700 yards, gyroes 42-43 degrees left. One definite torpedo hit,
indicating damage, was heard by personnel in the after torpedo room
approximately two minutes after firing. Sixteen depth charges were dropped.
Fifty-two minutes after firing, when again at periscope depth, the target
could not be distinguished among the 12 ships and 4 escorts sighted.

Torpedo Attack No. 6 - As a result of a contact report by the HOE,
and in a coordinated attack, contact was made on a 10-12 ship convoy at
23,400 yards at 0310 October 7th. In the approaching dawn, a radar depth
approach was made resulting in the attacking of a large AK. The last
four mark 14's and 23's were fired from the bow tubes on a 102 degree port
track, torpedo run about 2700 yards, gyroes 15½ - 18 degrees right. Hits
were not observed, but three timed torpedo explosions were recorded. Two
minutes later the target was observed settling, the bow at an angle of
40 degrees, and the ship completely under up to the amidships deck house.

- 2 -

— page 198 —
F05-4/A16-3
Serial 0428
CONFIDENTIAL

SUBMARINE SQUADRON FOUR
11/tel
Fleet Post Office,
San Francisco, California,
29 October 1944.

SECOND ENDORSEMENT to:
U.S.S. ASPRO Report
of Fifth War Patrol.

From: The Commander Submarine Squadron FOUR.
To: The Commander-in-Chief, United States Fleet.
Via: (1) The Commander Submarine Force, PACIFIC FLEET.
(2) The Commander-in-Chief, U.S. PACIFIC FLEET.

Subject: U.S.S. ASPRO - Report of Fifth War Patrol.

1. The fifth war patrol of the U.S.S. ASPRO resulted in
6 attacks, 5 of which were independent and the 6th coordinated. All
attacks resulted in the sinking or damaging of the enemy.

2. It is regretted that the grounding on 1 October, just
as a firing position was reached, spoiled an otherwise good approach.
The next hour and a half provided some tense moments as the ASPRO
played "leapfrog" with the bottom and "hide and seek" with a deter-
mined plane overhead. The Tanker and Peru which escaped on this
occasion were overtaken the following day and sunk.

3. The personnel situation of the ASPRO is under dis-
cussion and it is contemplated that 20-25% of the enlisted personnel
will be rotated. Satisfactory reliefs are available for all ratings
except electrician rates.

4. The fifth war patrol of the ASPRO, terminated by
expenditure of all torpedoes, was most aggressively carried out and
the Commander Submarine Squadron FOUR congratulates the Commanding
Officer, officers, and crew.

[SIGNATURE: W. V. O'Regan]
W. V. O'REGAN.

— page 199 —
F12-10/A16-3(15)
Serial 02399

CONFIDENTIAL

THIRD ENDORSEMENT
ASPRO Report of
Fifth War Patrol.

COMSUBSPAC PATROL REPORT NO. 560
U.S.S. ASPRO - FIFTH WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet.
To : The Commander-in-Chief, United States Fleet.
Via : The Commander-in-Chief, U.S. Pacific Fleet.

Subject: U.S.S. ASPRO (SS309) - Report of Fifth War Patrol.
(10 September to 25 October 1944).

1. The fifth war patrol of the ASPRO was conducted in
Southwest Pacific Areas in the South China Sea and off the coast of
Luzon. The ASPRO along with the U.S.S. CABRILLA (SS288) and the
U.S.S. HOE (SS258), formed an attack group with the commanding offi-
cer of the HOE as group commander.

2. This beautifully conducted, aggressive and tenacious
patrol resulted in six torpedo attacks during which twenty-four tor-
pedoes were fired for fourteen hits. These fourteen hits accounted
for two large AK's, one medium AK and a medium AO sunk, and a large
AK severely damaged; a performance in keeping with the splendid re-
cord of this fighting submarine.

3. Award of the Submarine Combat Insignia for this patrol
is authorized.

4. The Commander Submarine Force, Pacific Fleet, congra-
tulates the commanding officer, officers, and crew for this outstand-
ing and highly successful patrol. In her five patrols the ASPRO has
the outstanding record of having sunk fourteen ships, including a
submarine, for a total of 84,300 tons, and damaged eight ships for
59,020 tons. The ASPRO is credited with having inflicted the follow-
ing damage upon the enemy during this patrol, all of which was accom-
plished in areas under the operational control of the Commander Task
Force SEVENTY-ONE who is requested to assume credit accordingly:

S U N K

1 - Large AK (EU) - 7,500 tons (Attack No. 1)
1 - Medium AO (EU) - 5,000 tons (Attack No. 2)
1 - Medium AK (EC) - 5,500 tons (Attack Nos. 3 & 4).
1 - Large AK (EU) - 7,500 tons (Attack No. 6)

TOTAL SUNK 25,500 tons

- 1 -
SUBMARINE FORCE, PACIFIC FLEET

Care of Fleet Post Office,
San Francisco, California,
1 November 1944.

NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
ENTERING PATROL AREA.

[HANDWRITTEN: LAW
13 DEC 44]

[STAMP: EXTRA - ORIGINAL
SORG. MICRO
PHOTO-LAB OP-16
RETURN TO F-4253]