U.S.S. SEGUNDO (SS-398) — war patrol report SS-398_SEGUNDO.pdf

— page 1 —
START OF REEL
AR-1-80
JOB NO. 6-108

1.0
145 2.8
2.5
50
3.2
2.2
OPERATOR [HANDWRITTEN: C. Miller]
40
2.0
1.8
DATE [HANDWRITTEN: 1-20-80]
1.25 1.4 1.6

THIS MICROFILM IS
THE PROPERTY OF
THE UNITED STATES
GOVERNMENT

ARTMENT
P
OF DEFENSE
UNITED STATES OF AMERICA
MICROFILMED BY
NPPSO-NAVAL DISTRICT WASHINGTON
MICROFILM SECTION
REEL TARGET
START AND END
NDW-NPPSO-5210/1 (6-78)

— page 2 —
[HANDWRITTEN: SEGUNDO (SS-398)]
[HANDWRITTEN: WORLD WAR II PATROL FILE]

[HANDWRITTEN: ALL MATERIAL ON THIS REEL IS DECLASSIFIED]

[HANDWRITTEN: FOR DECK LOGS MAY 1944 - DECEMBER 1945]
[HANDWRITTEN: CONSULT NATIONAL ARCHIVES WHICH HAS CUSTODY.]

[HANDWRITTEN: J.A. KOONTZ]

— page 3 —
Division of Naval History
Ships' Histories Section
Navy Department

HISTORY OF USS SEGUNDO (SS 398)

Our submarines were employed in our mounting offensive in the Pacific
to cut enemy communications to his great sea empire, even attacking ship-
ping in Japanese home waters. Our subs were also used to support fleet
actions as pickets, weather stations, landing reconnaissance raiders, and by
attacking combat units including ASW vessels.

Though named for a rare fish of the Cavalla family, torpedoes from
the USS SEGUNDO became familiar sounds to the Japanese as they smashed into
the sides of their merchant ships; officially credited with only 20,000
over 500 tons displacement. However, many smaller craft were sunk and several
damaged.

The keel for this submarine was laid on 14 October 1943 at the U. S.
Navy Yard, Portsmouth, New Hampshire. On 5 February 1944, Mrs. John L.
Sullivan, wife of the Assistant Secretary of the Treasury, christened the
ship as she slid down the ways. She was accepted by the Navy at the com-
missioning ceremonies on 9 May when Lieutenant Commander J. D. Pulp, USN,
came aboard as commanding officer.

She arrived at Pearl Harbor on 25 July, and sailed on 21 August for
her first patrol. On the night of 8 September she delivered the operational
plan to the HARDHEAD off Siargao Straits, and the following day arrived in
her patrol area with instructions to conduct surface or submerged patrol
in contact with an American task force during the 12th as it delivered
air strikes against the Eastern Philippine Coast. On the morning of the follow-
ing morning two friendly planes came straight in and strafed the SEGUNDO
as she was diving, but fortunately their shots fell short.

On 14 September she joined the Offensive Reconnaissance Group "Zoo".
This group consisted of thirteen submarines forming a scouting line be-
tween the Palaus and Nansei Shoto. Their purpose was to report and intercept
any enemy force attempting to hamper our occupation of the Palau Islands.
No contact was made and on 24 September the SEGUNDO joined a coordinated
attack group known as "Wilkin's Bears" with the WHALE and SEAHORSE. She
proceeded to her patrol area in the Luzon Straits and the upper part of
the South China Sea. It was a very uneventful patrol, with no ships worthy
of torpedo fire being contacted. She returned to Majuro on 21 October 1944
for refit.

The SEGUNDO departed Majuro on 16 November, and after topping off
with fuel at Saipan, arrived in her patrol area in Luzon Straits and South
China Sea on 1 December. She was now a unit of a pack known as "Roy's
Rangers" consisting of the TREPANG, RAZORBACK, and SEGUNDO. These wolf
packs had been organized similar to the Germans in the Atlantic to make
our patrols more effective. A total of nine ship contacts were made, but
only one developed into an attack. This occurred on the evening of 6 December
1944; all three vessels of the wolf pack were able to attack, and the
effectiveness of the coordinated attack group as a potent destructive power
was amply demonstrated, sinking 7 of the convoy.

— page 4 —
-2- USS SEGUNDO (SS 398)
The SEGUNDO made two night surface attacks on this convoy of seven
merchant ships, heavily escorted. The first was delivered against a large
vessel which was later i identified as the 6,933 ton freighter KENJO MARU.
Six torpedoes were fired. The target zigged towards the SEGUNDO while the
torpedoes were running to present about a 1050 starbcard track. One hit was
seen from the bridge and two others were heard below. As the SEGUNDO pulled
clear to reload, the target stopped, so the skipper chose to make his next
attack on the undamaged ships of the convoy. The second attack was made on
an overlapping target of three ships. Six more torpedoes were fired. The
near right hand ship, evidently loaded with ammunition, completely disin-
tegrated. Due to the flash and shock of this tremendous explosion observation
of other hits was difficult, but one additional hit was seen by the star-
board lookout. The center ship and point of air which had been the largest
radar pip began to grow smaller at a range of 1600 yards, and was completely
lost at 3900 yards, indicating that the ship sank. The latter ship was the
5,794 ton freighter YASAKUNI MARU.
The SEGUNDO then reloaded and proceeded with the intention of sinking
her cripple of the first attack. She closed in time to see the RAZORBACK
administer the coup de grace, as the ship erupted in flames from stem to stern.
Contacts made during the remainder of this patrol were disappointing in that
they were either too small for torpedo fire, or they escaped in the Island
passes of the Luzon Straits. She departed the patrol area on 2 January 1945,
and arrived in Guam on the 5th.
The submarine got underway on 1 February and arrived in the patrol
area in the northern part of the East China Sea on the 7th to conduct her
third war patrol. Three torpedo attacks were made during this patrol on
unescorted ships near the Korean Coast in extremely shallow water. The
first attack was a night surface attack on 6 March on a small ship steering
a steady course at 9 knots. Four torpedoes were fired, but all missed due
to fire control errors.
A medium size ship was attacked on the night of 10 March. After track-
ing the target for 1½ hours on a steady course at 7 knots, four torpedoes
were fired. All ran erratic and missed. The SEGUNDO had maneuvered into
position three miles from an island to maintain dark background. The target
was not alerted and if the SEGUNDO was sighted the lockouts must have thought
she was a fishing vessel.
The next night an attack was made on a medium freighter. Four torpedoes
were fired and two hits were scored. The first blew the stern off. The
second hit amidships and the ship sank within two minutes. The SEGUNDO
departed her patrol area on 14 March, and arrived at Pearl Harbor on the 26th
for aupplies.
The sub sailed out of Pearl Harbor on 26 April for her fourth war
patrol. She stood by on lifeguard duty on 14 and 15 May, but there were no
opportunities to render services. On the 16th she steamed to her patrol area
in the East China Sea and the Yellow Sea. Seven two masted schooners of
about 100 tons each were sunk by gunfire near the Korean Coast on 29 May
1945. These schooners were part of a fleet of over 100 apparently carrying
food from China to Japan. Two nights later four torpedoes were fired at a

— page 5 —
-3- USS SEGUNDO (SS 398)

large four masted full rigged ship of about 1250 tons. One hit amidst.
The ship immediately broke in two and disappeared. Another four masted ship
was contacted on 3 June 1945. The SEGUNDO made a fast pass at 500 yards,
firing automatic weapons at topside personnel and discouraged return fire.
She then checked fire of her automatic weapons and proceeded to destroy
the target with twelve hits from the deck gun, firing leisurely at point
blank range.

On the night of 9 June two whalekiller type patrol chasers trying
a submarine trap were contacted near Port Arthur. The night was clear and
dark, but targets could be seen at 2000 yards with binoculars. One target
showed a dim glow which provided a point of aim. Taking advantage of land
background, the SEGUNDO closed at high speed until all gun crews could see
the target, then turned to bring all guns to bear, slowed speed, and opened
fire. The target group appeared to be a tug with tow, so all guns except the
20mm were designated to fire at the leader. Tracers provided the necessary
illumination and both Whalekillers returned fire with 37mm's. The leader's
gun was silenced immediately, and the gun of the trailer was silenced by
the 20mm. The trailer attempted to ram the SEGUNDO, but the 20 mm emptied
a full magazine into his pilot house, setting it afire and putting it out
of control. The deck gun continued to blast away until both ships were
sunk.

On 11 June contact was made with a ship and two escorts off the Shantung
Promitary in the Yellow Sea. The convoy was zigging radically in dense fog
with visibility of about 500 yards. Four torpedoes were fired at a close
range. Three hits were scored on the small freighter and she sank in three
minutes. Four more torpedoes were fired at the larger escort, but with
negative results. The SEGUNDO returned to Midway on 21 June 1945, where on
29 June Commander Fulp was relieved as Commanding Officer by Lieutenant
Commander S. L. Johnson, USN.

The SEGUNDO's fifth patrol was conducted in the Sea of Okhotsk,
beginning on 10 August 1945. After receiving word of Japan's surrender
on 15 August she patrolled outside Kurile Island chain awaiting orders.
She departed her patrol station on 24 August and steamed toward Tokyo Bay.
Enroute to Tokyo Bay on 31 August, she intercepted a Japanese submarine the I401 and escorted her prize back to
Sagami Wan on 29 August. In company with eleven other submarines she steamed from
Bay on 3 September enroute to Pearl Harbor. After a short stop-over the
submarine proceeded to Seattle, Washington -- her war duty done.

The USS SEGUNDO earned four Battle Stars on the Asiatic-Pacific Area
Service Medal for participating in the following operations:

1 Star/Western Caroline Islands Operation
Capture and Occupation of southern Palau Islands -- 6 September -
14 October 1944
1 Star/Assaults on the Philippine Islands -- 9 September - 24 September 1944
1 Star/Iwo Jima Operation
Assault and occupation of Iwo Jima -- 15 February - 14 March 1945

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-4- USS SEGUNDO (SS 398)

1 Star/Okinawa Gunto Operation
    Assault and occupation of Okinawa Gunto -- 14 May - 13 June 1945

1 Star/Second Submarine War Patrol -- 16 November 1944 - 5 January 1945

She also received the Navy Occupation Service Medal, Asia, for the
period 2 - 3 September 1945. As of July 1953, the SEGUNDO is active with
the U. S. Pacific Fleet.

STATISTICS

OVERALL LENGTH                 312 feet
BEAM                           27 feet
SPEED                          20 knots
DISPLACEMENT                   1525 tons
COMPLEMENT                     8 officers and 72 men

Compiled: 4 December 1953

— page 7 —
U.S.S. SEGUNDO (SS398)
Care of Fleet Post Office
San Francisco, California
21 October 1944

SS398/A16-3

Serial (015)

C-O-N-F-I-D-E-N-T-I-A-L
[STAMP: DECLASSIFIED-ART. 0445, OPNAVINST 5510.1C]
BY [HANDWRITTEN: OPO9Bst] DATE [HANDWRITTEN: 8/16/72]

From: The Commanding Officer, U.S.S. SEGUNDO (SS398).
To : The Commander in Chief, United States Fleet.
Via : (1) The Commander Submarine Division ONE FORTY TWO
(2) The Commander Submarine Squadron FOURTEEN.
(3) The Commander Submarine Force, Pacific Fleet.
(4) The Commander in Chief, United States Pacific Fleet.

Subject: U.S.S. SEGUNDO (SS398) - Report of War Patrol Number One.

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

1. Enclosure (A), covering the first war patrol of this vessel
conducted in the Western Pacific Ocean and Luzon Strait area during the
period from 21 August 1944 to 21 October 1944, is forwarded herewith.

[SIGNATURE: J. D. FULP, Jr.]

[STAMP: 9354 FILMED]

— page 9 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of First War Patrol.
29 August 1944
Enroute Saipan. Conducted training dives and drills.
30 August 1944
Enroute Saipan. Conducted training dives and drills.
31 August 1944
Enroute Saipan. Conducted training dives and drills.
1 September 1944
0500(L)
Enroute Saipan. Conducted training dives.
Set clocks back to minus ten time.
2 September 1944
0848(K)
0932(K)
1407(K)
1443(K)
2211(K)
2228(K)
2310(K)
3 September 1944
SD Contact (Aircraft Contact No. 1) 28 miles, unidentified.
Submerged.
Surfaced all clear.
Sighted plane on horizon 025°(T) about 12 miles coming in.
Dove to 200 feet. Aircraft Contact No. 2.
Surfaced all clear.
Sighted Sarigan Island bearing 272°(T) about 50 miles.
Sighted Anatahan Island bearing 250°(T).
Radar contact on Sarigan about 45 miles.
0615(K)
0748(K)
0818(K)
1046(K)
1137(K)
Effected rendezvous with escort, U.S.S. DOWNES (DD375).
Proceeding as requisite toward Tanapag Harbor, Saipan.
First of many friendly plane contacts, mostly B-24, PBM, and F6F.
Sighted Saipan Island bearing 150°(T) about 50 miles.
Pilot furnished by U.S.S. HOLLAND, Lt. RHATIGAN came on board.
Moored starboard side to U.S.S. WHALE in nest alongside U.S.S.
HOLLAND, TANAPAG HARBOR, SAIPAN, M.I.
1220(K)
Commenced fueling from YO 108.
1710(K)
Fueling completed; received 35,620 gals.
1715(K)
Liberty party returned on board, having viewed the devastation
of Saipan.

-3-
ENCLOSURE (A)

— page 10 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of First War Patrol.
(A) PROLOGUE
Ship was commissioned May 9, 1944 at Building Yard, Navy Yard,
Portsmouth, N.H. On May 19, 1944 ship got underway under own
power for the first time and moved to Lower Harbor, Portsmouth
N.H., for two days of cleaning ship, dry dives, and drills.
Inspected by Board of Inspection and Survey on 24 May 1944 and
declared completed on the same day. On 25 May 1944 made first
trim dive and commenced intensified training period in Portsmouth
Area. Availibility at Navy Yard on June 8 and 9 for minor work.
Departed June 10, 1944 for Newport, R.I., where thirty torpedoes
were fired for contract trials. On June 14, 1944 arrived at New
London, Conn., and was depermed. Commencing June 15, 1944 opera-
ted out of New London undergoing intensified training, firing
six torpedoes and all guns. Went on Marine Railway at New London
to inspect torpedo tubes and shutters. Departed New London on
June 26, 1944 for Canal Zone, arriving NOB, Balboa on July 5,
1944. Was sound tested in Gulf of Panama on July 7, 1944. De-
parted Balboa on July 9th and arrived at Pearl on July 25th.
Received voyage repairs and on July 30, 1944 commenced training
period out of Pearl which lasted until August 18th. During this
period seven days were spent in special experimental exercises
for Comsubstrainpac. Fired seven torpedoes, all guns, both day
and night. Made many practice approaches, and operated as unit
of a pack on an inbound convoy. Loaded ship on 19 and 20 Aug.,
and departed Pearl on first patrol on 21 August 1944.
Condition on leaving Pearl:
1. One 5in./25 cal. gun mounted aft.
2. All antennas forward.
3. One 40 mm gun on bridge level aft.
4. One 20 mm gun on 'bridge level fwd.
5. One 20 mm gun on deck fwd.
6. Mark 8 TBTS installed.
7. APR installed.
8. VHF installed.
9. Twelve ton negative tank.
10. Bow planes altered to rig in at 15 degrees dive.
Item of Military Deficiency:
1. No 5 in. ammunition scuttle.
-1-
ENCLOSURE (A)

— page 11 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of First War Patrol.
(B) NARRATIVE
21 August 1944
1330(VW) Departed Submarine Base, Pearl Harbor, T.H., in company with
U.S.S. SEAHORSE and U.S.S. WHALE as unit of coordinated attack
group known as Wilkins Bears and composed of U.S.S. SEGUNDO,
U.S.S. SEAHORSE, and U.S.S. WHALE of which Capt. C.W. WILKINS,
U.S.N., Commanding Officer of SEAHORSE is Group Commander.
2000(VW) Escorted by PC 1077 until dark.
Set clocks back one half hour to plus ten time.
22 August 1944
0400(W) Enroute Saipan. Conducted training dives and drills during day.
Set clocks back one hour to plus eleven time.
23 August 1944
Enroute Saipan. Conducted training dives and drills. Made
approach on other subs of group.
24 August 1944
Enroute Saipan. Conducted training dives and drills. Made
approach on other subs of group.
1200(X) Set clocks back one hour to plus twelve time.
25 August 1944
Enroute Saipan. Conducted training dives and drills. Made
approach on other subs of group. Test fired all guns at a
moored balloon.
26 - 27 August 1944
0224(Y) Enroute Saipan. Conducted training dives and drills.
Crossed international date line; added a day..
28 August 1944
2000(M) Enroute Saipan. Conducted training dives and drills.
Set clocks back to minus eleven time.

-2- ENCLOSURE (A)

— page 12 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of First War Patrol.

29 August 1944
Enroute Saipan. Conducted training dives and drills.
30 August 1944
Enroute Saipan. Conducted training dives and drills.
31 August 1944
Enroute Saipan. Conducted training dives and drills.
1 September 1944
0500(L) Enroute Saipan. Conducted training dives.
Set clocks back to minus ten time.
2 September 1944
0848(K) SD Contact (Aircraft Contact No. 1) 28 miles, unidentified.
0932(K) Submerged.
1407(K) Surfaced all clear.
Sighted plane on horizon 025°(T) about 12 miles coming in.
1443(K) Dove to 200 feet. Aircraft Contact No. 2.
2211(K) Surfaced all clear.
2228(K) Sighted Sarigan Island bearing 272°(T) about 50 miles.
2310(K) Sighted Anatahan Island bearing 250°(T).
Radar contact on Sarigan about 45 miles.
3 September 1944
0615(K) Effected rendezvous with escort, U.S.S. DOWNES (DD375).
Proceeding as requisite toward Tanapag Harbor, Saipan.
0748(K) First of many friendly plane contacts, mostly B-24, PBM, and F6F.
0818(K) Sighted Saipan Island bearing 150°(T) about 50 miles.
1046(K) Pilot furnished by U.S.S. HOLLAND, Lt. RHATIGAN came on board.
1137(K) Moored starboard side to U.S.S. WHALE in nest alongside U.S.S.
HOLLAND, TANAPAG HARBOR, SAIPAN, M.I.
1220(K) Commenced fueling from YO 108.
1710(K) Fueling completed; received 35,620 gals.
1715(K) Liberty party returned on board, having viewed the devastation
of Saipan.

-3- ENCLOSURE (A)

— page 14 —
CONFIDENTIAL
Subject:
0708(1)
1704(1)
1832(1)
2005(1)
2008(1)
2030(I)
2043(1)
2048(1)
2105(1)
2127 (1)
2330(1)
9 September 1944
0030-(1)
0622(1)
0631(1)
1300(1).
1853(1)
1940(1)
10 September 1944.
0027(1)
0619(1)
0740(1)
U.S.S. SEGUNDO (S$398) - Report of First War Patrol.
Submerged. Waiting for weather to clear up. We are now about
100 miles from Surigao on the Saipan bearing.
Surfaced.
Sunset.
Picked up light SJ Radar interference bearing 307° (T). Am now
steering 251°(T) heading for rendezvous with HARDHEAD. No fix
in 24 hours; not sure of our position.
Radar contact on peaks of Mindanao 38 miles ahead.
Definite Radar interference at 320° (T). Changed course to
330°(T).
SJ contact 355°(R) 4400 yards. We spent the rest of the night
trying to figure out why the SJ did not detect the HARDHEAD until
range had closed to 4400 yards. Manned tracking stations.
Exchanged recognition signals:
Lying about 20 yards off HARDHEAD, passed ComSubPac Op Plan
#3-44 and other papers to them in a watertight can with a heaving
line. Sea is flat calm - light airs.
Backed clear, Set course for our waiting area which is bounded
as follows: Lat. 10° to 20°N., Long. 127° to 127°-40°E. This
area lies about 60 miles off Surigao Strait. Our primary mission
now is attack, modified in that large forces are to be reported
prior to being attacked.
Moonrise.
Entered waiting area.
Sunrise. Foul weather. Heavy rains.
Submerged for the day. This will be the first all day dive for
the ship. My orders are to conduct surface or submerged patrol
at discretion, passing through 11°N. on southern course at 1200
(I), and on northerly course at 0000.(1) daily.
Weather, has cleared up.
Surfaced. Scattered rain squalls, all of which are picked up by
the SJ Radar.
SJ Radar out of commission for two hours. Found two bad tubes
in high voltage unit.
Patrolling waiting area.
Moonrise..
Sunrise. Scattered rain squalls.
Submerged. Maintaining a continuous high periscope watch.

-5-
ENCLOSURE (A)

— page 15 —
CONFIDENTIAL
Subject:
1835(1)
1841(1)
11 September 1944
0618(1)
0933(1)
1834(1)
12 September 1944
0621(1)
0655(1)
0700(1)
U.S.S. SEGUNDO (SS398) Report of First War Patrol.
Sunset..
Surfaced, Continued to patrol waiting area.
Patrolling waiting area.
Sunrise.
Sighted stick which looked very much like a periscope at first.
Sunset. Weather is good except for heavy rain squalls.
Patrolling waiting area.
Sunrise. Heavy rains, sky almost completely overcast with black
cumulonimbus clouds.
The surprise of a lifetime! SD contact on from eight to twelve
friendly aircraft, ranges varying from eleven to twenty miles.
Aircraft contact no. 7. SD contacts had closed to less than two
miles on one group of planes. Visibility now is zero, as we are
in the middle of a torrential rain squall. Manned VHF. Sighted
an Avenger-Hellcat team about one half mile on port quarter at an
altitude of about 500 ft. Established communication via VHF and
asked them, "Are you lost? If so, we can give you a position". The
Avenger answered with, "Negative. We are on routine patrol".
"Routine patrol" indeed sixty miles from Surigao Strait! We
then heard the Avenger tell the Hellcat "OK, Joe, leave him alone",
They circled us for a few minutes, then shoved off. We have had
no word about any friendly forces in the vicinity and I am begin-
ning to wonder about our position when at 0720 we got an SJ contact
on four ships at 22,000 yds. I begin to see the light now. At
about 0730 the rain let up and we are able to identify two ESSEX
class carriers, one INDEPENDENCE class carrier, and one CHICAGO
class cruiser, plus a number of destroyers. The SD is so full of
contacts at this time that we are not able to keep track of them
all. We kept working to westward and southward of the task force
to be in position to act as a potential lifeguard. The range
never closed to less than 20,000 yds., and there was never any
indication that we were embarrassing their movements. We were
investigated by an Anti-Sub team (Avenger-Hellcat) about every
fifteen minutes during the rest of the day, and by a different
team most of the times, as we could tell by the plane's numbers.
I would not have relished the job of getting an enemy sub into an
attack position on that task force.

-6-
ENCLOSURE (A)

— page 16 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of First War Patrol.
13 September 1944
By 1100 the foul weather ceased and the day turned into a fine,
bright, and fair one. We kept at a respectable distance and
watched the whole show. Our Communications Officer, Lt. AUBREY,
came into submarines just recently from the new YORKTOWN, and was
able to tell us all about what was going on, and what to expect.
His services were invaluable in this respect.
We were able to establish VHF communications with all the Anti-
Sub teams. I am glad that there was no occasion for them to ask
us to perform lifeguard work.
By 0930 of this day we had decoded all the messages concerning
this strike, They had started coming in at 0600, but we had de-
coded some messages of lesser importance first, the new King Uncle
calls not being effective yet.
At 1054 we started working to the eastward and at 1300 to the
northward of the task force to get clear of its assumed retire-
ment course. No enemy planes were seen.
0620(I)
0802(1)
0904(1)
1124(1)
Enroute station in the Offensive Reconnaissance Group "200".
Sunrise. Heavy rains.
Aircraft contact No. 8. Lookout sighted two aircraft as pin-
points against the reddish back ground under the rising sun, at
a position angle of about 1/4 degree, estimated range 18 miles,
headed directly for us. It is our job to identify all planes, if
possible, and make report if they are enemy. We stayed on the
surface until I estimated the range to have closed to five miles,
at which time we dove. I am almost certain they are Hellcats, but
they could be ZEKES or HAPS, Belly-tanks çan look a lot like
bombs. While diving I watched them through the periscope until
they are about a mile away and was not able to identify them for
sure. When the ship had just begun to break through at 30 feet
they strafed us but their shots fell short. These planes came in
too low for IFF signal.
Surfaced, Commenced sending report of planes saying that they
looked like HELLCATS but that they had strafed us. Com Third
Fleet will know whether or not any of his own planes were in our
vicinity. I honestly believe that the planes are friendly and
that a trigger-happy young pilot was just testing his guns.
Reached assigned station in Offensive Reconnaissance Group and
commenced patrolling at a speed of eleven knots through the water,
Steering course 055 degrees and reverse on legs of two hours
duration.

-7-
ENCLOSURE (A)

— page 17 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of First War Patrol.
1250(1)
Finally managed to clear our contact report and had it come back
on the FOX at 1300. It is very discouraging to find that as much as
five hours may be required to get a receipt for a contact report.
Why not send it direct to Com Third Fleet who is only a few hun-
dred miles away, instead of through NPM?
1835(1)
Sunset.
14 September 1944
Patrolling assigned station.
0300(1)
Moonrise.
0621(1)
Sunrise.
0705(1)
SD and sight contact on two planes, friendly, at 7 miles. Iden-
tified as Hellcats. Aircraft contact No. 9.
0824(1)
SD and sight contact on two planes, friendly, at 9 miles. Iden-
tified as Hellcats. Aircraft contact number 10, believed to be
same as number 9.
15 September 1944
Patrolling assigned station. To-day is Dog Day.
0351(1)
Moonrise.
0621(1)
Sunrise, Clear weather.
1834(1)
Sunset.
16 September 1944
0440(1)
0621(1)
0949(1)
1023(1)
1834(1)
17 September 1944
0621(1)
1834(1)
18 September 1944
0622(I)
1008(1)
1036(1)
Patrolling assigned station.
Moonrise.
Sunrise. Weather is clear.
Submerged for trim.
Surfaced.
Sunset.
Patrolling assigned station.
Sunrise. Clear weather.
Sunset.
Patrolling assigned station.
Sunrise.
Commenced moving to the northward, maintaining the scouting line.
Sighted a stick floating upright in the water looking very much
like a periscope.
-8-
ENCLOSURE (A)

— page 21 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of First War Patrol.
At 2014 the ship zigged left and was identified as either a
CHIDORI class TB or a PC. Up to now he had certainly looked
like a submarine; I had been almost sure it was the WHALE. Went
to battle stations. At this point the Mark 18 which was being
hastily returned to No. 7 tube after a battery charge slipped
under the stop bolt. Did not want to risk a hot run in the tube
that an up angle to radar depth might have caused so stayed at
periscope depth. Target appeared to be passing at 3000 to 4000
yards and was going pretty fast. We have no solution. At 2045
the target had almost disappeared on base course 055°. Torpedo
is secured in no. 7 tube so came to radar depth, but could not
get a pip on him.
2059(1)
Surfaced. Although there is only a half moon it is as bright as
day. Am maintaining radar silence with a continuous watch on
the APR at 150 MCS. Tuning through the lower frequencies occa-
sionally.
27 September 1944
0120(I)
Lionnset. Commence making two sweeps with the SJ radar every
three minutes.
0143(1)
Strong contact on the APR at 155 MCS. Contact appeared all at
once, did not gradually build up from a weak signal as they us-
ually do. He must have homed in on the SJ.
0144(1)
Sighted exhaust flare of plane astern, estimated distance two
miles, passing from starboard to port. When bearing about 200°
(R) he turned away for a minute then turned toward and commenced
flashing a white light directly at us. Since we did not have
the proper replies to his challenge, made a quick dive to 100 ft.
at 0146(1) Came up to periscope depth in twenty minutes but
0246(1)
0251(1)
0606(1)
*0624(1)
could not see any floating flares as previously reported by BARB
and QUEENFISH. Aircraft contact no. 17.
Surfaced. Maintaining radar silence.
Another strong APR contact at 150 MCS which lasted about three
minutes then abruptly disappeared. From this time until dawn
we had about a dozen APR contacts on 150 and 240 MCS, none of
which lasted very long.
Submerged. Sea is calm with moderate swell. Intend to patrol
today in our lane on the TAKAO - BOJEADOR line. Just before
diving received relay of Commander BEARS message changing our
communication plan and directing a rendezvous at 0200(H) on the
29th.
Sighted the morning patrol, a MAVIS. He passed us about 5 miles
and disappeared to the southward. Aircraft contact No. 18.

-12-
ENCLOSURE (A)

— page 22 —
CONFIDENTIAL
Subject:
0646(1)
1852(1)
2014(1)
2222(1)

28 September 1944
0147(1)

0214(1)
0525(1)

0646(1)

0901(1)
0935(1)
0916(H)
0945(H)
1016(H)
1021(H)
1302(H)

1342(H)
1749(H)
1834(H)

1925(H)

2006(H)
2006(H)

2015(H)

2030(H)
U.S.S. SEGUNDO (SS398) - Report of First War Patrol.

— page 24 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of First War Patrol.

30 September 1944

0014(H)         Picked up interference on SJ radar receiver. After about ten
                minutes we succeeded in exchanging recognition signals and calls
                with SEAHORSE. She is apparently on a nearly parallel course.
0216(H)         Sighted SEAHORSE.
0303(H)         Rendezvous completed. Received new operating procedure, communi-
                cation plan, and new "rotating patrol area within a rotating patrol
                area" plan from CTG.
0328(H)         Moonset. Am keying SJ radar for two sweeps every three minutes.
0522(H)         Submerged. Am maintaining continuous high periscope watch and
                exposing vertical antenna ten minutes out of each hour.
0555(H)         Sunrise. Bright, clear and calm.
1754(H)         Sunset.
1906(H)         Surfaced. Proceeding southward toward new area. Maintaining
                radar silence.
2158(H)         Picked up SJ radar interference bearing 172°(T). Was standing a
                receiver watch on the SJ at the time.
2210(H)         Received message from CTG changing area assignments.
2217(H)         Weak APR contact at 150 MCS.

1 October 1944

0219(H)         Manned SJ radar and exchanged recognition signals and calls with
0315(H)         WHALE by radar.
0343(H)         Sighted submarine bearing 135°(T). Determined to be WHALE. Ex-
                changed calls by light.
0437(H)         Moonset.
0530(H)         Submerged. Maintaining continuous high periscope watch; exposing
                vertical antenna for ten minutes out of each hour.
0547(H)         Sunrise. Seas are picking up; looks like we are in for a blow.
1443(H)         Seas are heavy now. It is necessary to make 60 turns to maintain
                depth control at 58 feet.
1753(H)         Sunset.
1900(H)         Commenced receiving message from CTG over vertical antenna con-
                taining orders to form a scouting line.
1904(H)         Surfaced. Set course for new station at best speed. Maintaining
                radar silence, but standing receiver watch on SJ.
2130(H)         Exchanged recognition signals with SEAHORSE and sent out our
                SJ radar. Commenced keying SJ radar once every three minutes.
2330(H)         On new station; patrolling.

-15-            ENCLOSURE (A)

— page 27 —
CONFIDENTIAL

Subject: U.S.S. SEGUDNO (SS398) - Report of First War Patrol.

2031(H)         Moonrise.
2200(H)         A flash of SJ radar interference beaming 120°(T) which did not
                reappear. Only reasonable assumption it that we received a
                reciprocal from the WHALE who is to northward of us.

6 October 1944

0440(H)         Received a message from the CTG ordering us to search to south-
                ward of him attempting to intercept forces mentioned in a contact
                report which we do not have. Our orders have been to guard the
                area frequency and pack frequency except during NPM FOX skeds
                when we are to guard those skeds. This put me in a quandary; we
                are more than 190 miles from the search position, are virtually
                surrounded by land, and in a heavily air-patrolled area.
0444(H)         Submerged.
0515(H)         Came to 51 ft. to transmit a request to SEAHORSE for a relay of
                the contact report using vertical antenna. Spent the next hour
                at this depth and transmitted our message seven or eight times,
                but without success. The wing antennas are grounded out, resis-
                tance readings 8,000; 10,000, and 12,000, ohms.
0537(H)         Sunrise. Heavy weather.
0600(H)         While at 51 ft. sighted three masts bearing 320°(T). Commenced
                approach. At 0615 identified these objects to be two small sail-
                ing schooners and one power trawler. The schooners were disposed
                on either bow of the trawler, either tacking or zigging radically
                and the trawler following their movements. They were headed to-
                ward the passage between CALAYAN and CAMIGUIN ISLANDS from the
                time we sighted them until 0710, at which time they changed base
                course to the right and headed for the passage between FUGA and
                CAMIGUIN ISLANDS. I considered that a torpedo attack would be
                a waste of torpedoes for the following reasons:
                (1) Torpedo run would be too far for such a small target.
                (2) Even the trawler is doubtful as a torpedo target.
                (3) Rough sea would probably cause torpedoes to broach at the
                shallow depth setting required.

                I then considered a gun action and decided against it for the
                following reasons:
                (1) Air patrols.
                (2) Rough sea too rough for gun's crew to be on deck.
                (3) Lack of an ammunition scuttle limits me to the ten rounds
                of 5" that are in the ready locker. Passing ammunition up through
                the after battery hatch is out of the question. Passing ammuni-
                tion up through the gun trunk is awkward in smooth water and
                dangerous in rough water. These five inch shells weigh 100 lbs.

-18-                                                            ENCLOSURE (A)

— page 29 —
CONFIDENTIAL
U.S.S. SEGUNDO (SS398) - Report of First War Patrol.
Subject:
8 October 1944
0000(H)
0520(H)
0540(H)
1739(H)
1813(H)
2220(H)
2242(H)
2303(H)
2330(H)
9 October 1944
0100(H)
0445(H)
0810(H)
0811(H)
0859(H)
1052(H)
Commenced sending message to SEAHORSE and WHALE advising them we
have cleared area.
Submerged.
Sunrise. Moderate sea. Clear skies.
Sunset.
Surfaced.
Sighted ITBAYAT IS.
Sighted BATAN IS.
Moonrise.
Have gotten the resistance of one antenna up to 820,000 ohms.
Both the others are still low.
Enroute Majuro. Am forced to run on three engines to avoid cont-
act with friendly surface forces,
Passed between ITBAYAT and BATAN ISLANDS.
Exchanged calls with SHARK (SS314) via SJ radar.
Contact on SD radar at 12 miles, unidentified. Aircraft Contact
No. 37.
Submerged.
Surfaced.
Sighted ship dead ahead at 1055 identified ship as U.S. Submarine,
At 1058 sighted a small pursuit plane overhead peeling off into a
dive from an estimated altitude of 10,000 ft. and made quick dive.
The other submarine was 6,400 yds. away by radar at this time, and
either dove for the plane that zoomed us or dove because he saw us
dive. At llll exchanged calls and notes with SEADRAGON (SS194)
via sonar. Although the pursuit dropped no bombs, nor did anyone
on the bridge get hit by bullets, decided to stay down for a while
and let him run out of gas. Aircraft contact No. 38.
Surfaced. Found that the dive had grounded out our one good
1304(H)
antenna again.
1525(H)
1528(H)
Sighted submarine bearing 0600(T) and identified as friendly.
Believe it is BLACKFISH. Manned radar to communicate with him.
BLACKFISH dove at a range of about six miles. Slowed down, manned
sound gear, and attempted to communicate with him, but without
success. Changed course to the right and went to 16 knots skir-
ting will clear of his diving position.
1554(H)
BLACKFISH surfaced and continued on her way.

-20-
ENCLOSURE (A)

— page 34 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of First War Patrol.
(F) SHIP CONTACTS
NO. | TIME-DATE | LAT-LONG | TYPES | INITIAL RANGE | EST. COURSE & SPEED | HOW CONTACTED | REMARKS
C. | 0720(I) | 10-12 N. | 2 CV | 22,000 Yds. | 280° (T) | R. | Associated with air-
| 9-12-44 | 127-20 E. | 1 CVL | | 25 Kts. | | craft Contact No..7.
| | | 3 CA | | | | Contact made in low
| | | Many DD | | | | visibility (heavy
| | | | | | | rains). Identified
| | | | | | | as friendly when
| | | | | | | seen about 15 min.
| | | | | | | later.
2. | 2004(I) | 21-25 N. | TB or PC | 6,000 Yds. | 055° (T) | P | Had small angle on
| 9-26-44 | 120-46 E. | | (est.) | 15 Kts. | (night) | bow, when sighted,
| | | | | | | mistook for sub until
| | | | | | | range had closed and
| | | | | | | ship had zigged left
| | | | | | | about 50 degrees.
3. | 2006(H) | 21-20 N. | SC or PC | 9,000 Yds. | 020° (T) | SNB | Avoided.
| 9-28-44 | 120-40 E. | | (est.) | 10 Kts. | |
4. | 0600(H) | 19-08 N | 1 Trawler | 10,000 Yds | Various | P |
| 10-6-44 | 121-29 E. | 2 Sailboats | (est.) | | (at 51 ft) |

-25-

ENCLOSURE (A)

— page 35 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of First War Patrol.
(G) AIRCRAFT CONTACTS
CONTACT NUMBER | 1 | 2 | 3 | 4 | 5 | 6
Date | 9-2-44 | 9-2-44 | 9-6-44 | 9-6-44 | 9-7-44 | 9-7-44
Time (Zone) | 0848 (K) | 1407 (K) | 0854 (I) | 1335 (I) | 1116 (I) | 1325 (I)
Position: Lat. | 17°22'N | 17°02'N | 13°56′N | 13°30′N | 11°34'N | 11°24'N
Long. | 149°37'E | 148°12'E | 136°23'E | 135°17'E | 131°24'E | 131°02'E
Speed | 15 Kts. | 18 Kts. | 16 Kts. | 16 Kts. | 14 Kts. | 16 Kts.
Course | 257° T | 270° T | 242° T | 242° T | 242° T | 242° T
Trim | Surf. | Surf. | Surf. | Surf. | Surf. | Surf.
Minutes Since Last
SD Radar Search | 0 | 0 | 3/4 | 3/4 | 3/4 | 3/4
Number | 1 | 1 | 1 | 1 | 1 | 1
Type | Unk. | PBM | B-24 | B-24 | Unk. | Unk.
Probable Mission | Pat. | Pat. | Pat. | Pat. | Pat. | Pat.
How Contacted | R | P | R | R | R | R
Initial Range (Miles) | 28 | 12 | 30 | 26 | 28 | 23
Elevation Angle | Unk. | 8° | 2° | 7° | Unk. | Unk.
Range & Relative
Bearing of Plane
When It Detected
Submarine | Unk. | 12 Mi.
090° | Unk. | Unk. | Unk. | Unk.
(State (Beau-
Sea: ( | 0 | 0 | 0 | 0 | 0 | 0
fort
(Direction(Rel) | Calm | Calm | Calm | Calm | Calm | Calm
Visibility (Miles) | 25 | 25 | 25 | 25 | 25 | 25
(Height in
Clouds: ( | 6,000 | 6,000 | 4,000 | 4,000 | 4,000 | 3,000
Ft.
(Percent
Overcast | 10 | 10 | 30 | 25 | 50 | 60
(Bearing (Rel) | X | X | X | X | X | X
Moon: (Angle | X | X | X | X | X | X
(Percent Illum | X | X | X | X | X | X
Type of S/M Camouflage on this patrol: Modified Grey.
-26-
ENCLOSURE (A)

— page 37 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of First War Patrol.

CONTACT NUMBER | 13 | 14 | 15 | 16 | 17 | 18
|----|----|----|----|----|----
Date | 9-26-44 | 9-26-44 | 9-26-44 | 9-26-44 | 9-27-44 | 9-27-44
S Time (Zone) | 1359 (I) | 1740 (I) | 1826 (I) | 1858 (I) | 0144 (I) | 0624 (I)
U Position: Lat. | 21°29'N | 21°25'N | 21°25'N | 21°25'N | 21°11'N | 21°28'N
B Long. | 121°01'E | 120°46'E | 120°46'E | 120°46'E | 120°17'E | 120°04'E
M Speed | 2 Kts. | 2 Kts. | 2 Kts. | 2 Kts. | 10 Kts. | 2 Kts.
A Course | 210° T | 210° T | 210° T | 210° T | 270° T | 000° T
R Trim | Per. | Per. | Per. | Per. | Surf. | Per.
I Minutes Since Last | X | X | X | X | X | X
N SD Radar Search | | | | | |
E Number | 1 | 1 | 1 | 1 | 1 | 1
A Type | TOPSY | MAVIS | MAVIS | MAVIS | Unk. | MAVIS
I Probable Mission | Trans. | H. | H. | H. | H. | H.
R How Contacted | P | P | P | P | SNB | P
C Initial Range(Miles) | 12 | 10 | 14 | 7 | 2 | 9
R Elevation Angle | 1° | 1° | 1° | 2° | 4° | 2°
A Range & Relative | ND | ND | ND | Unk. | Unk. | ND
F Bearing of Plane | | | | | |
T When It Detected | | | | | |
  Submarine | | | | | |
C (State (Beau- | 2 | 2 | 2 | 2 | 2 | 2
O Sea: ( fort) | | | | | |
N (Direction(Rel) | 240° | 240° | 240° | 240° | 240° | 240°
D Visibility (Miles) | 25 | 25 | 25 | 25 | 25 | 25
I (Height in | 10,000 | 10,000 | 10,000 | 10,000 | 5,000 | 5,000
T Clouds: ( Ft. | | | | | |
I (Percent | 30 | 40 | 40 | 40 | 40 | 40
O Overcast | | | | | |
N (Bearing(Rel) | X | X | X | X | X | X
S Moons (Angle | X | X | X | X | X | X
  (Percent Illum | | | | | |

Type of S/P Camouflage on this patrol: Modified Grey.
-28-
ENCLOSURE (A)

— page 40 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of First War Patrol.

CONTACT NUMBER | 31 | 32 | 33 | 34 | 35 | 36
|----|----|----|----|----|----
Date | 10-4-44 | 10-5-44 | 10-5-44 | 10-5-44 | 10-5-44 | 10-6-44
S Time (Zone) | 1358 (H) | 0907 (H) | 0950 (H) | 1017 (H) | 1306 (H) | 0946 (H)
U Position: Lat. | 19°00'N | 19°00'N | 19°00'N | 19°00'N | 19°00'N | 19°08'N
B | Long. | 120°55'E | 121°30'E | 121°30'E | 121°30'E | 121°30'E | 121°25'E
M | Speed | 2.5 Kts | 2.5 Kts. | 2.5 Kts. | 2.5 Kts. | 2.5 Kts. | 17.4 Kts
A Course | 150° T | 310° T | 310° T | 310° T | 130° T | 310° T
R Trim | Per. | Per. | Per. | Per. | Per. | Surf.
I Minutes Since Last | X | X | X | X | X | 0
N SD Radar Search | | | | | |
E | Number | 1 | 1 | 1 | 1 | 1 | 1
A Type | NELL | BETTY | TOPSY | BETTY | NELL | MAVIS
I Probable Mission | H or Trans. | H | Trans. | H | H | H
R | How Contacted | P | P | P | P | P | SDB
A Initial Range(Miles) | 6 | 4 | 4 | 5 | 7 | 6
F Elevation Angle | 1° | 3° | 10° | 2° | 1° | 8°
T Range & Relative | | | | | |
  Bearing of Plane | ND | ND | ND | ND | ND | Unk.
  When It Detected | | | | | |
  Submarine | | | | | |
C (State | 5 | 4 | 4 | 4 | 4 | 4
O Sea: (Beau- | | | | | |
N fort | | | | | |
D (Direction(Rel) | 060° | 060° | 060° | 060° | 060° | 040°
I Visibility (Miles) | 15 | 15 | 20 | 10 | 20 | 10
T (Height in | | | | | |
I Clouds: (Ft. | 2,000 | 30,000 | 30,000 | 30,000 | 30,000 | 1,500
O (Percent | | | | | |
N Overcast | 80. | 80 | 80 | 80 | 80 | 10
S (Bearing(Rel) | X | X | X | X | X | X
  Moon:(Angle | X | X | X | X | X | X
  Percent Illum | X | X | X | X | X | X

Type of S/M Camouflage on this patrol: Modified Grey.

-31-
ENCLOSURE (A)

— page 46 —
CONFIDENTIAL
U.S.S. SEGUNDO (SS398) - Report of First War Patrol.

C. Sound Conditions.

    Sound conditions were generally consistant with the predictions of
    Nav Ships 943-F.

(O) DENSITY LAYERS

    1.  Various bathythermograph cards showed every possible combination of
        negative and isothermal gradients, radical changes occurring in
        twenty four hours time. The following results are broad general-
        izations at least for the month of September.

        (a) Along the east coast of the PHILIPPINES a gradual negative curve
            of from 2° to 4° was found running from 20' to 300'.
        (b) South of MIYAKO SHIMA moderate negative gradients of 3° to 7°
            were found breaking between 150' to 250'.
        (c) There were moderate negative gradients at depths below 200' off
            southern FORMOSA.
        (d) Very strong negative gradients in excess of 10° were frequent
            between 100' to 200' around northern LUZON.

    2.  In using the bathythermograph to assist diving operations, the
        salinity factor had to be taken into consideration on several
        occasions. With an isothermal gradient we were able to go from
        50' to 250' off southern FORMOSA without flooding or pumping. This
        tends to verify the salinity charts of the "Submarine Supplement
        to Sailing Directions". It is believed that a bathythermograph
        which includes the salinity element along with depth and tempera-
        ture would be useful.

    3.  Approximately thirty cards were recorded and fixed and are being
        forwarded under separate cover to the Vice Chief of Naval Operations
        in accordance with instructions.

(P) HEALTH, FOOD, AND HABITABILITY

    1.  HEALTH:- Health was excellent; better than if the same men had
        stayed ashore for the same length of time. There were only a few
        colds and only a few complaints of constipation. The lookouts and
        radiomen suffered most of the headaches; the former because of the
        many days scouting and the latter because of the many frequencies
        required to be guarded. Approximately 700'aspirin tablets were
        used. There were two injuries as follows:

-37- ENCLOSURE (A)

— page 50 —
SUBMARINE DIVISION 142

FB5-142/A16-3
Serial: 058

CONFIDENTIAL
FIRST ENDORSEMENT to
CO USS SEGUNDO Conf. ltr.
SS398/A16-3, Ser. 015, dated
21 October 1944.

From:
To :
Via :

Subject:

1.
ted in areas East and South of FORMOSA as part of a coordinated attack
under the tactical command of Captain C. W. Wilkins in the
U.S.S. SEAHORSE. The U.S.S. WHALE was the other submarine in the
group. The patrol extended for a period of sixty days of which only
twelve were spent in the assigned area due to additional assignments
enroute.

2.
No contacts worthy of torpedo fire were made even
though excellent area and shipping lane coverage was maintained in
spite of formerly numerous in contacts. This is undoubtedly disappoint-
ing to a fighting ship and crew but it is bound to become more fre-
quent as Japanese shipping is reduced toward the zero point.

3.
The SEGUNDO returned in excellent material condition
and with no major defects. The U.S.S. BUSHNELL will refit her in the
normal period assisted by the refit crew of Submarine Division ONE
FORTY TWO.

4.
Though no damage to the enemy resulted on this long
and arduous patrol the officers and men gained experience which should
serve them well on coming patrols. Given the chance, the SEGUNDO is
capable of showing results.

Copy to:
CO USS SEGUNDO.

Care of Fleet Post Office,
San Francisco, California,
24 October 1944.

The Commander Submarine Division 142.
The Commander in Chief, United States Fleet.
(1) The Commander Submarine Squadron FOURTEEN.
(2) The Commander Submarine Force, Pacific Fleet.
(3) The Commander in Chief, U. S. Pacific Fleet.

U.S.S. SEGUNDO (SS398) - Report of First War Patrol,
Comments on.

The First War Patrol of the U.S.S. SEGUNDO was conduc-

[SIGNATURE: D. F. WEISS]
D. F. WEISS,
Acting.

— page 51 —
FC5-14/A16-3
Serial 0114.

CONFIDENTIAL
SECOND ENDORSEMENT to
USS SEGUNDO Report of
First War Patrol.

From:
To :
Via :

Subject:

1.
in the first endorsement.

2.
congratulated on the completion of this arduous patrol and it is
hoped that on the next one the SEGUNDO will be afforded opportuni-
ties of coming to grips with the enemy.

Copy to: Comsubdiv 142.
CO SEGUNDO.

SUBMARINE SQUADRON FOURTEEN

Care of Fleet Post Office,
San Francisco, California,
24 October 1944.

The Commander Submarine Squadron Fourteen.
The Commander-in-Chief, United States Fleet.
(1) The Commander Submarine Force, Pacific Fleet.
(2) The Commander-in-Chief, U.S. Pacific Fleet.

U.S.S. SEGUNDO (SS398) - Report of First War
Patrol; Comments on.

Forwarded, concurring in the remarks contained

[SIGNATURE: W. D. WILKIN]
W. D. WILKIN.

— page 52 —
FF12-10/A16-3(15)
Serial 02484

SUBMARINE FORCE, PACIFIC FLEET
Care of Fleet Post Office,
San Francisco, California,
8 November 1944.

[HANDWRITTEN: 11r]
NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
ENTERING A WAR AREA.

[HANDWRITTEN: LAN
21 Nov 44]

CONFIDENTIAL
THIRD ENDORSEMENT to
Submarine Patrol Report of
U.S.S. SEGUNDO
First War Patrol.

PAC PATROL REPORT NO. 561
U.S.S. SEGUNDO - 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. SEGUNDO (SS398) - Report of First War Patrol.
(21 August to 21 October 1944).

1. The first war patrol of the SEGUNDO was conducted in
areas between Formosa and Luzon and in support of the attacks upon
and occupation of Palau. The SEGUNDO along with the U.S.S. SEAHORSE
(SS304), U.S.S. VEILE (SS239), and for a short period the U.S.S.
GROUPER (SS214), formed a coordinated attack group with the command-
ing officer of the SEAHORSE as group commander.

2. Despite alert, aggressive and thorough area coverage
in the face of strong enemy anti-submarine measures, the SEGUNDO had
no enemy contacts. Enemy traffic during this period, as a result of
attacks by our air forces, was very thin. The SEGUNDO, however, has
reason to be proud of her heads-up performance as a member of a
reconnaissance group which supported the surface and air forces during
their attack upon Palau.

3. Award of Submarine Combat Insignia for this period is
not authorized.

4. The Commander Submarine Force, Pacific Fleet, congratu-
lates the commanding officer, officers and crew for this important
patrol and hopes that the next patrol will provide opportunities to
come to grips with the enemy.

C. A. LOCKWOOD, Jr.

DISTRIBUTION:
(Complete Reports)
Cominch (7) | Comsubspac (20)
CNO (5) | SUBAD, MI (3)
Cincpac (6) | ComsubspacSubordcon (1)
Intel.Cen.Pac.Ocean Areas (1) | Commanders, Pacific (2)
Cinclant (1) | Submarine Div. (2)
Comsowespac (1) | All Submarines, Pacific (1)
S/M School, NL (1) | [SIGNATURE: C. A. Hynes] [HANDWRITTEN: EXTRA]
S/M Base, PH (8) | [HANDWRITTEN: SORG. MICRO]
Comsopac (2) | E. L. HYNES, 2nd, [STAMP: PHOTO-LAB OP-16]
Comsubspac (2) | Flag Secretary. [STAMP: RETURN TO F-425]
CTF 72 (2)
Comnorpac (1)

— page 59 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.
This change of base course has put BALINTANG between us and the
convoy. To succeed in an end-around seems impossible on account of
the fact that the air cover will require us to wait awhile before
surfacing, then we will have to go around BABUYAN ISLAND as well
as BALINTANG. By this time the ships will be at anchor in CALAYAN.
If we try to cut corners we will be sighted, the visibility is
perfect and seas are nearly flat, and the convoy will be alerted
and may ruin the chances of TREPANG and RAZORBACK, who are to the
southward of us. It appears that the best thing to do is to main-
tain the status quo and try to catch them along the north coast of
LUZON to-morrow. At 1415 we sighted the tips of two masts of a
freighter and a wisp of smoke from another ship bearing 265°(T),
which meant they had "gotten by". This was the only sighting of
the day and even this soon disappeared. At 1525 we saw the last
of the planes and at about the same time lost the convoy on sound.
Surfaced. As soon as china sked was finished sent contact report
to TREPANG and RAZORBACK and suggested trying to regain contact
along north coast of LUZON to-morrow.
1810(H)
1931(H)
Received attack report from RAZORBACK saying she had/ fired at
one AK
and one AP out of the convoy. This make's us feel a lot better,
although she did not state results.
2 December 1944
0329 (H)
0413(H)
0530(H)
Patrolling BALINTANG CHANNEL.
APR contact on 150 MCS, submerged. Plane not sighted. Aircraft
contact. No. 3.
Surfaced. Seas are making up.
Submerged for the day. The sea is state five with intermittent
bad visibility. We are cruising at 100 feet, coming up for a look
every 20 minutes, and having a hard time holding the boat at
periscope depth at two-thirds speed.
1757(H)
2140(H)
2213(H)
2215(H)
Surfaced. Patrolled BALINTANG CHANNEL to westward of BALINTANG
ISLAND. Current is three point five knots setting about 300°(T).
APR contact 150 MCS, weak, faded. Aircraft contact No. 4.
APR contact back again, getting stronger and being keyed.
Submerged for APR contact, plane not sighted.
2315(H)
Surfaced.
و
3 December 1944
Patrolling BALINTANG CHANNEL to westward of BALINTANG ISLAND.
Sea is heavy, state five or six; wind is gale strength. Moon is
bright with good visibility except when raining.

-6-
ENCLOSURE (A)

— page 75 —
CONFIDENTIAL

Subject:
U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.

1315(H) Slo wed to full speed and started a battery charge.
1730(H) Experienced an effective sort of jamming of the SD radar and at
        1736 dove for a pip on same. This may or may not have been a
        contact, as it was soon discovered that the "jamming" was nothing
        more than "too much grass". Someone had unknowingly turned up
        the sensitivity knob. However, the pip seemed real enough.
        Aircraft contact No. 11.

1810(H) Surfaced and commenced patrolling the Southern approaches to
        SABTANG from 10 to 20 miles west of BALINTANG Island. We figured
        that the convoy would have had to make good more than twelve
        knots to have gotten by us. The reason for beating it down to
        this position was to be able to intercept the ships in case they
        passed through or by SABTANG instead of anchoring over night.
        As soon as the China schedule was finished, sent contact report
        to RAZORBACK, and gave them our interception position.
        At 1925 picked up interference on SJ radar that did not appear
        to have been caused by an SJ. Weak and sweeping fast.

2050(H) Got radar contact on three ships bunched closely together,
        bearing 309°(T), range 8,400 yards. This soon developed into
        five ships - a convoy of three and two escorts. Ship contact #5.

2055(H) Estimate of the situation here was as follows:
        (1) Could possibly be the three medium AKs of our morning
        convoy continuing onward. The two large AKs and one or possibly
        two escorts having anchored.
        (2) Position of contact jibes exactly with where the convoy
        should have been at a speed of advance of 8 knots.
        (3) The short initial range indicates that targets are smaller
        than the medium AKs of the morning convoy, these ships having
        been lost on radar at 17,400 yards after surfacing this morning.
        Went to battle stations and commenced tracking from ahead at
        about eight thousand yards. Was not able to see the ships on
        account of rain, although the night was very bright, there being
        a three-quarter moon.
        Being very much in doubt as to the identity of this group,
        decided to lead them down to BABUYAN Island, which we could use
        for a back drop while we looked them over. At about 2150 we
        stuck our bow in toward BABUYAN Island, stopped, and let the
        ships steam across our stern. At a range of four thousand yards
        the escorts were fairly well defined and were made out to be
        either SCs or PCs, but the three ships of the convoy could not
        be made out clearly. As near as we could tell they were some
        type of infantry landing craft.
        At 2233 went ahead again, tracking them on base course 180°(T),

-22-
ENCLOSURE (A)

— page 81 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.

1804(H)
1845(H)
1850(H)
1941(H)
2030(H)
2146(H)
SOMESPAC territory would have taken us at least as far down as
VIGAN, further, even, after the MAVIS held us down so long.
Surfaced and set course for own area.
APR contact at 153 MCS. Aircraft contact No. 18.
Submerged with APR contact' at saturation.
Surfaced.
While on course 015°(T), 15 degrees to the left of the sea, at
12 knots, taking spray over the bridge, but notwater, the ship
dove into two mountaincus waves. The ship was able to partly
recover from the first one, but the second one caught her in a
dazed condition and submerged her to 36 feet, everything below
the look-out platforms being under green water. The J.0.0.D.
saw these waves coming end yelled to the lookouts to "hang on".
His shout alerted the Quartermaster who jumped for the hatch and
closed same as soon as a great volume of water began to pour in.
At the same time "Stop Engines" was rung up on the engine order
telegraphs and Maneuvering tripped the engines. The throttle-
man on watch in the forward engine room could not close his
induction flappers right away because the down-pouring water
swept him away, and considerable water was taken into this
engine room. However, in the interim between the first wave
and the really bad second wave he got both the engine induction
flapper and the ship's ventilation supply flapper closed.
Fortunately, the ship was all buttoned up by the time she dove
under the second wave. Only a negligible amount of water was
taken into the Control Room and no damage. Maneuvering Room
flapper was shut; no water at all. After Engine Room was able
to close their flapper promptly. Some-water no damage.
Forward Engine Room much water, slight damage to instrument
panels and instruments, but no other damage..
Ship's Ventilation Supply line caused the only real damage,
pouring a large amount of water on the after battery compt. deck
and into the radio room. Flooded out the TBL transmitter, the
INC7 MC announcing systems, and the RAK power pack, No water
got to the after battery, but a lot of bunks were flooded out.
It was with fear and trepidation that the conning tower hatch was
opened. Scarcely expecting to find anyone at all left on the
bridge, it was a great relief to find everyone present and
accounted for. It is believed that the action of closing the
hatch and shutting up the engine rooms saved the ship from
serious damage.
The INC 7 MC systems back in commission, operating normally.
Radiomen commenced working on the transmitter.

-28-
ENCLOSURE (A)

— page 83 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.
0550(H)
APR contact on 153 MCS. Aircraft contact No. 21.
0555(H)
Submerged on account of APR contact and half-light.
0716(H)
Sighted three large unidentified aircraft coming in with zero
angle on bow. Aircraft contact No. 22.
0719(H)
Went to 100 feet to avoid these planes.
1006(H)
Sighted two RUFES with 45 degree port angle on bow which changed
at a range of 3 miles to a zero angle on bow. Went to 150 feet.
Aircraft contact No. 23.
1206(H)
In position lat. 21-02 N., long. 121-11 E.,0.0.D. sighted a
floating mine through periscope on port beam, distance - without
exageration - TEN FEET. Needless to say the 0.0.D. was rendered
speechless for a moment or two. When the C.O. got to the conn-
ing tower the mine was bearing dead on 180 degrees relative and
looked as big as a house in low power. In high power the threads,
wires, etc. on the horns were plainly visible as were such minor
details as gaskets on hendhole plates etc. The mine was spherical,
about 30 inches in diameter, was free of marine growth, but its
paint had worn down to the red-lead. It was not rusty. Only
one horn was threaded. We wondered what we would do if the cable
became ensnarled in our props and commenced to reel in. Rough
sea made keeping it in sight difficult, but it was not long before
we ascertained that it was drawing aft and was being cast by the
wind across our stern to the starboard quarter.
At 1219, with the mine roughly a thousand yards astern and no
longer in view, surfaced and manned, automatic weapons. Reversed
course and ran somewhat over a mile, then came back to orginal
course. Had travelled just about a mile in this direction when
at 1253 an SD contact at eith miles forced us down. Aircraft
contact No. 24. It was slightly hazardous to search for a mine
in such a rough sea as was then running, so gave up the search
and remain submerged.
Our reckoning of current, wind, etc., allows that this mine
probably was brought up from the vicinity of the BABUYAN Islands.
We know for a fact that at present the current is carrying it
toward the coast of CHINA via FORMOSA STRAIT at a rate of 30
miles per day. So it probably is just as well that we didn't
sink it.
1359(H)
Ship contact No. 9. Sighted two masts and smoke bearing 062°(T),
hauling left. Came to normal approach course and commenced
approach. By 1440 this sighting had resolved into two whale-
killer boats in column about a half mile apart, slow speed, on
course 320°(T). Both were smoking a good deal, and both had
regular depth charge racks aft. Knocked off the approach at an

-30-
ENCLOSURE (A)

— page 84 —
CONFIDENTIAL

Subject: U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.

1816(H) estimated range of 4000 yards. Lost sight of them at 1545.
1915(H) Surfaced. Set course for BASHI CHANNEL and to-morrow's patrol
2041(H) station off KOTO SHO.
2043(H) Exchanged recognition signals and calls with RAZORBACK.
2120(H) APR contact at 153 MCS. Aircraft contact No. 25.
    Submerged with above APR contact at half strength.
    Surfaced. At this point we gave up the idea of trying to reach
    to-morrow's patrol station off KOTO SHO and decided instead to spend to-
    morrow on the SABTANG - BARANBI line. In view of contact report
    from PLENNY off west coast of LUZON on two medium Oilers and two
    medium transports, loaded, headed Northward, this station should
    be as good as any. Since this outfit could pass through our area
    either the twenty-ninth or thirtieth, we will try to catch them
    the twenty-ninth and RAZORBACK the thirtieth.

29 December 1944

    Patrolling the shipping route between BARANBI and SABTANG about
    twenty miles West of ITBAYAT Island in a heavy sea.
0454(H) APR contact at 153 MCS. Aircraft contact No. 26.
0455(H) Submerged. Rough sea.
1815(H) Surfaced. Rough sea. Set course for BASHI CHANNEL and thence
    to patrol station Northeast of KASHO TO.
2112(H) Picked up SJ radar interference bearing 003°(T).
2150(H) Exchanged recognition signals and calls with KRAKEN (SS370).
2305(H) Lost radar contact on Y'AMI Island.

30 December 1944

    Proceeding across BASHI CHANNEL in a northerly direction toward
    days patrol station Northeastward of KASHO TO. The sea is rough
    and confused and the sky is bright, but overcast. The moon is
    full.
0044(H) APR contact at 153 MCS. Aircraft contact No. 27.
0048(H) Submerged just Eastward of GADD ROCK.
0132(H) Surfaced.
0616(H) Submerged to patrol Eastward of KASHO TO. RAZORBACK, we
    thought, is patrolling between KASHO TO and FORMOSA.
0845(H) Sighted KASHO TO well enough to get a fix on it.
1813(H) Surfaced.
1825(H) APR contact at 155 MCS, rather weak. Contact does not appear
    to be from aircraft radar. Commenced maneuvering to attempt

-31- ENCLOSURE (A)

— page 88 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.

(C) WEATHER

The weather while on station was of typhoon character with
December First and Sixth being the only clear days in the South
China Sea. The wind varied from force 5 to 9 and the sea from
state 5 to 8. In LUZON STRAIT the wind and sea moderated slightly.
Frequent rain squalls were encountered throughout the area. The
sky was almost completely overcast with dense layers of clouds
making navigation difficult. The sea and wind were from North-
northeast to northeast. Special precautions taken were to keep
the maneuvering room flapper shut and to ventilate inboard when
heading into the sea at slow speed.

(D) TIDAL INFORMATION

Throughout the area the current followed the predicted trend dis-
cribed by the Current Charts of the Japanese theater of war (H.O.
Misc. No. 10,057-A). This publication was very valuable and we
were able to calculate our position with a fair amount of accuracy.
In LUZON STRAIT the current and tidal flow agreed with the in-
formation given on U.S.C. & G.S. Chart No. 4705.
Off the Southeast coast of FORMOSA the current followed the
predicted trend of the Japanese current in accordance with the
pilot chart.

(E) NAVIGATIONAL AIDS

No navigational lights were sighted during the patrol. A large
tower was observed on the northeast end of KASHO TO Island.
This tower is not charted.

-35- ENCLOSURE (A)

— page 95 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.
TUBES FIRED:
#1
#2
#3
#4
#5
#6
TRACK ANGLE:
135 S 135 S 135 S 135 S 135 S 135 S
GYRO ANGLE:
003-10 000-30 001-00 004-10 003-40 005-20
DEPTH SET:
6'
6'
6'
6'
6'
6'
POWER:
-
HIT OR MISS:
MISS
MISS
HIT
HIT
MISS
MISS
ERRATIC:
Unk
Unk
No
No
Unk
Unk
MARK TORPEDO:
18-1
18-1
18-1
18-1
18-1
18-1
SERIAL NO:
56414
56347
56374
55133
55906
55686
MARK EXPLODER:
8-5
8-5
8-5
8-5
8-5
4-7
SERIAL NO:
8750
9310
9675
9143
8924
17373
ACTUATION SET: Con.
Con.
Con.
Con.
Con.
Con.
ACTUATION ACTUAL:
--
--
Con.
Con.
--
--
MARK WARHEAD:
18-2
18-2
18-2
18-2
18-2
18
SERIAL NO:
1490
1814
2518
1427
1994
478
EXPLOSIVE:
TPX
TPX
TPX
TPX
*TPX
TPX
FIRING INTERVAL:
--
10
15
10
12
18
TYPE SPREAD:
DIVERGENT.
SEA CONDITIONS:
5
OVERHAUL ACTIVITY: U.S.S. BUSHNELL.
REMARKS:
Used speed reduction for shallow depths as given by ComSubPac
dispatch.
Commenced firing with 135 track. Plot reported target zigged
right to a 105 track before end of firing.
-42-
ENCLOSURE (A)
KODAK
DO SAFETY FILM

— page 97 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.
TUBES FIRED: | # 1 | # 2 | #.3 | # 4 | # 5 | # 6
TRACK ANGLE: | 105 S | 105 S. | 105 S | 105 S | 105 S | 105 S
GYRO ANGLE: | 005-30 | 003-20 | 006-20 | 006-00 | 003-00 | 004-30
DEPTH SET: | 8' | 8' | 8' | 8' | 8' | 8'
POWER: | -- | -- | -- | -- | -- | --
HIT OR MISS: | MISS | HIT | HIT | HIT | HIT | MISS
ERRATIC: | Unk | No | No | No | No | Unk
MARK TORPEDO: | 18-1 | 18-1 | 18-1 | 18-1 | 18-1 | 18-1
SERIAL NO: | 55776 | 55626 | 55343 | 54860 | 56398 | 55231
MARK EXPLODER: | 8-5 | 8-5 | 8-5 | 8-5 | 8-5 | 8-5
SERIAL NO: | 9794 | 9865 | 8447 | 9053 | 9691 | 9212
ACTUATION SET | Con. | Con. | Con. | Con. | Con. | Con.
ACTUATION ACTUAL: | -- | Con. | Con. | Con. | Con. | --
MARK WARHEAD: | 18-2 | 18-2 | 18-2 | 18-2 | 18-2 | 18-2
SERIAL NO: | 2929 | 2000 | 2044 | 2920 | 2185 | 1951
EXPLOSIVE: | TPX | TPX | TPX | TPX | TPX | TPX
FIRING INTERVAL: | -- | 10 | 11 | 10 | 10 | 12
TYPE SPREAD: DIVERGENT.
SEA CONDITIONS: 5 or 6.
OVERHAUL ACTIVITY: U.S.S. BUSHNELL.
REMARKS: Used speed reduction for shallow depth as given by ComSub Pac
dispatch.

-44- ENCLOSURE (A)

— page 98 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.

(I) MINES

A floating mine was sighted by periscope at noon on 28 December
1944, in position lat. 21-02 N., long. 121-11 E. Surface
to sink it with gunfire, but could not locate it in the heavy sea
then running. Was forced down by an airplane after searching
for a half hour.
No running activities noted.

(J) ANTI-SUBMARINE MEASURES AND EVASION TACTICS

(1). The important convoy attacked on the night of December 6th was
escorted by four escorts none of which appeared to be radar-
equipped, as on two or three occasions we passed within 1000
yards of them on the surface without being detected. This convoy
had no air cover.

(2). On the night of 24 December, while waiting for a southbound
convoy to come out of SABTANG, we picked up another convoy of
three small ships and two escorts in the exact position the
real convoy should have been had it not anchored at SABTANG.
We did not know at the time whether it had anchored or not.
This could have been a decoy, although we were not able for sure
to identify the ships except that they were not the ones we
were waiting for.

(3). Many assorted planes were seen over a convoy on 1 December
BALINTANG. No planes were seen with the convoy on 24 December
near ITBAYAT; one MAVIS was seen with this same convoy the follow-
ing day southwest of SABTANG; and one BETTY and one MAVIS were
seen over the same convoy one day later along the coast of LUZON.
In this latter instance, after the convoy had passed without
being attacked, the MAVIS flew back and forth over our position
for nearly two hours, whether by design or chance we do not know.

(K) MAJOR DEFECTS AND DAMAGE

(1) Engine air induction system:
(a) While plowing through a large wave, when water came down
the main induction in a solid stream, a demonstration of the
practicality of the present air induction system was beheld.

-45- ENCLOSURE (A)

— page 100 —
CONFIDENTIAL
Subject:
(M) RADAR
U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.
spare. On December 26th the RAK 7 Power Pack, TBL 12, and 1MC-
7MC were completely flooded out. They were washed down with
fresh water and dried out with hot air. It was necessary to
replace indicator 2-4 (Motor solenoid indicator bulb socket and
resistor) in the TBL. All equipment was in normal operating
order in nine hours after flooding.
(2) NPM Schedules.
While in LUZON STR.IT poor reception was experienced on all
HAIKU frequencies especially between 1115 Z and 1215 Z.
From time of surfacing until 1115 Z, 0645 KCS was copied and
came in fairly well.
At 1115 Z, 9090 signal was strongest until 2000 Z.
There is a definito fade out on all frequencies from 2000 Z
to 2200 Z.
At 2200 Z, 13655 KCS usually come in strength four to five.
Enemy jamming was noted on all frequencies but was not strong
enough to hamper reception seriously. Reception in the China
seas was generally good with best reception on 9090 KCS and
6045 KCS.
(3) Attack Group Radio.
Experienced no communication difficulties on wolf pack fre-
quencies. Maintained a running file of task unit designation,
but at times found it impossible to break all calls.
(4) Chungking Radio:
While in area the 1000 Z and 1800 Z schedules were copied and
received clearly. None of the information received concerned
our patrol area.

The SD-4 was operated to and from station and on several occasions,
while on station. The set gave no trouble and turned in very good
ranges on planes and land. Reliable ranges were, eight miles for
low flying planes, and twenty miles for medium altitude planes.
The IFF equipment was in most cases put in standby while the SD-4
was being operated.
The SJ-1 turned in a good performance being out of commission
only four hours during the patrol. The only casuality was in
the range unit where R 553 burned out and C 532 was shorted.

-47-
ENCLOSURE (1)

— page 102 —
CONFIDENTIAL

Subject: U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.

(P) HEALTH, FOOD, AND HABITABILITY

Health was in general excellent. One man suffered a trifle
from an abscess on the ear drum. Another man had a minute
particle of copper become embodied in his eye-ball when a fuze
exploded close to his face - not serious. There was one man
who had to have three boils lanced by the Chief Pharmacist's
Mate. The performance of duty of the Chief Pharmacist's
Mate continued to be outstanding for a man of his rating.

The food was nutritious, well-prepared, ample, and of sufficient
variety.

Habitability, while good, was impaired at times by the necessity
for ventilating inboard because of heavy seas. Great care was
taken, however, to bring the ship to a safe course and
ventilating outboard long enough to change the air in the boat
every two or three hours, and always just before the morning
dive and just after the evening surfacing.

(Q) PERSONNEL

The performance of duty of the officers was satisfactory with
one exception.
The performance of duty of all chief petty officers continued
to be above average.
The performance of duty of all enlisted ratings was satisfactory.

Number of enlisted men on board during patrol - 77.

Number of enlisted men qualified at start of patrol - 46.

Number of enlisted men qualified at end of patrol - 52.

Number of unqualified men making their first patrol - 9.

Number of enlisted men advanced in rating during patrol - 0.

(R) MILES STEAMED - FUEL USED

MAJURO to Area                 4,089.9 miles 46,500 gal.
In Area                        3,751.9 miles 30,850 gal.
Area to GUAM                   1,330.5 miles 21,850 gal.

-49- ENCLOSURE (A)

— page 104 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of Second War Patrol.
(V) REMARKS
1. We want to express our appreciation through the medium of this
report to Rear Admiral T. WITHERS, U.S.N., and his crew of real
shipbuilders at the Navy Yard, Portsmouth, New Hampshire, for
giving us this superb submarine. She is rugged, reliable, com-
fortable, and is complete as to minor detail in spite of having
been built in less than eight months. Design of various internal
fittings and equipment is excellent; not a day passes but that
we find some new indication of "the thought that has gone into
this" or "the pains taken with that". To Admiral WITHERS we
also want to send our thanks for the most excellent and complete
training facilities at Portsmouth which he made possible, and
which made it possible for the crew of the ship to operate it
like veterans from the first trim dive. We are as grateful for
that training as we are for the ship.
2. The events of twenty-four, twenty-five, and twenty-six December
were a bitter disappointment to the ship. The C.O. knows that
he was outwitted by the Japs on those days, but hopes, and feels,
that the lessons learned from this experience will prove valu-
able in later brushes with the enemy.
3. It was a pleasure to work with TREPANG and RAZORBACK. We would
like to go with them again.
-51-
ENCLOSURE (A)

— page 105 —
FB5-282/A16-3
Serial (01)
CONFIDENTIAL

FIRST ENDORSEMENT to
CO SEGUNDO (SS398) Ltr
SS398/A16-3, serial (002),
dated 5 January, 1945.

From:
To :
Via :

Subject: U.S.S. SEGUNDO (SS398) - Report of War Patrol Number Two.

1. The Second War Patrol of SEGUNDO was conducted in the
LUZON STRAITS area and the SOUTH CHINA SEA as part of a co-
ordinated attack group consisting of SEGUNDO, TREPANG, and RAZORBACK.
This group was known as Roy's Rangers and was under the command
of Commander ROY M. DAVENPORT, U.S.Navy, in the TREPANG. SEGUNDO'S
extended patrol over a period of fifty-one days, thirty days of which were
spent in the area. Submerged patrol during daylight was ordered by
the group commander. This patrol throughout was hampered by
monsoon of near typhoon intensity.

2. At about 1300 on December 1 SEGUNDO made contact with
what was apparently an important convoy judging from the amount of
air cover employed. RAZORBACK and TREPANG were submerged to south-
ward of SEGUNDO. Contact was first made to northwest of SEGUNDO and
then passed out of range on a general southerly course. The
Commanding Officer states that there was no provision made for
radio communication while submerged and he therefor could not get off
a contact report to the other two vessels to the southward which he
believed were submerged. It is believed that all pack vessels
have a schedule for radio listening while submerged and comply when
feasible.

3. A total of nine ship contacts were made but in spite of
real determination on the part of the commanding officer only one
was developed into an attack. This attack which occurred on the
evening of December 6, 1944, was the result of a contact report
by TREPANG. All three vessels of the pack were enabled to make
attacks and the effectiveness of the coordinated attack group methods
in detection and coordination as well as the potent destructive power
of such a group were amply demonstrated. SEGUNDO made two no
surface attacks on this convoy. The first was delivered on a large
vessel carrying extensive superstructure and identified in a later
attack by RAZORBACK as an A.P.(EU) six torpedoes were fired on a
135° starboard track with a torpedo run of about 3300 yards into
a state 5 sea. The target zigged towards while the torpedoes were
running to present about a 105° starboard track. One hit was seen
from the bridge and two were heard below.

-1-
SUBMARINE DIVISION TWO EIGHTY TWO
c/o Fleet Post Office, San Francisco, Calif.
9 January, 1945

The Commander Submarine Division TWO EIGHTY TWO.
The Commander-in-Chief, United States Fleet.
The Commander Submarine Squadron TWENTY EIGHT.
The Commander Submarine Force, Pacific Fleet.
The Commander-in-Chief, United States, Pacific Fleet.

— page 106 —
SUBMARINE DIVISION TWO EIGHTY TWO
FB5-282/A16-3 c/o Fleet Post Office, San Francisco, Calif.
(01)
9 January, 1945.
CONFIDENTIAL

FIRST ENDORSEMENT to
CO SEGUNDO (SS398) Ltr
SS398/A16-3, serial (002),
dated 5 January, 1945.

Subject: U.S.S. SEGUNDO (SS398) - Report of War Patrol Number Two.

3.
As SEGUNDO pulled out to make a reload the target stopped, so the
Captain chose to make his next attack on the undamaged ship of the
convoy. The second attack was made on an overlapping target of
three ships on a 105° starboard track at ranges between 1000 and
1800 yards. The near right hand ship evidently loaded with ammuni-
tion completely disintegrated. Due to the flash and shock of this
tremendous explosion observation of other hits was difficult but one
additional hit was seen by the starboard lookout and a total of four
to five hits were heard below. The center ship and point of aim
which had been the largest radar pip commenced to grow smaller at a
range of 1600 yards and was completely lost at 3900 yards indicating
that the ship sank. The ammunition ship was identified as a MANSEI
MARU type (page 192, O.N.I. 208-J) (EC) and the other as a large
AK (EU).

4.
SEGUNDO then made a reload and proceeded with the inten-
tion of sinking her cripple of the first attack only to see
receive two or three torpedo hits from RAZORBACK and burst into
flame.

5.
The other ship contacts made were a disappointment to
SEGUNDO. They were either too small for torpedo fire or they
succeeded in outwitting SEGUNDO in the island passes of the LUZON
STRAITS. It is believed however that in the case of the contact
on December 26th SEGUNDO should have made every effort to pursue
the large AK even if it did require running into areas assisted by
air force and that this action coupled with a contact report and
information that SEGUNDO was chasing was in order.

6.
The expert handling of SEGUNDO when she encountered the
two mountainous waves on the night of December 26th undoubtedly
prevented extensive damage. It appears that everyone on watch had
a veteran's appreciation of the situation and clicked instinctively.
The recommendations of the commanding officer in regard to the re-
arrangement of the engine inductions in the engine rooms is concurr-
ed in with the exception of the proposed automatic flapper tripping
device.

-2-

— page 108 —
FC5-28/A16-3
SUBMARINE SQUADRON TWENTY-EIGHT
Serial: 012
Care of Fleet Post Office,
San Francisco, California,
10 January 1945.

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

SECOND ENDORSEMENT to
CO SEGUNDO (SS398) conf. ltr.
SS398/A16-3, serial 002
dated 5 January 1945.

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

Subject: U.S.S. SEGUNDO (SS398) - Report of War Patrol Number TWO.

1. Forwarded, concurring in the comments of the Commander Sub-
marine Division TWO HUNDRED EIGHTY-TWO in the first endorsement.

2. The Squadron Commander congratulates the Commanding Officer,
officers and crew of the SEGUNDO on the extensive damage they inflicted on the
enemy on this, their second war patrol.

3. It is recommended that the SEGUNDO be credited with the
following:

SUNK
1 AK (MAUSEI MARU Type) EC 7700 tons
1 AK (large) EU 7500 tons
*1 AP (large) EU 5000 tons
TOTAL - 20,200 tons

*One-half of 10,000 estimated tons credited. Ship finally sunk by
RAZORBACK.

[SIGNATURE: J. M. WILL.]
J. M. WILL.

— page 109 —
26 JAN 1945

FF12-10/A16-3(15)
Serial 0217
CONFIDENTIAL

THIRD ENDORSEMENT to
SEGUNDO Report of
Second War Patrol.

COMSUBSPAC PATROL REPORT NO. 645
U.S.S. SEGUNDO - SECOND WAR PATROL.

From:
To :
Via :

Subject:

SUBMARINE FORCE, PACIFIC FLEET

Care of Fleet Post Office,
San Francisco, California.

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

The Commander Submarine Force, Pacific Fleet.
The Commander-in-Chief, United States Fleet.
The Commander-in-Chief, U.S. Pacific Fleet.

U.S.S. SEGUNDO (SS398) - Report of Second War Patrol
(16 November, 1944, to 5 January, 1945).

1. The second war patrol of the SEGUNDO, under the command
of Commander J. D. Fulp, Jr., U.S. Navy, was conducted in the Luzon
Strait-South China Seas Areas. The SEGUNDO, along with the U.S.S.
TREPANG (SS412) and the U.S.S. RAZORBACK (SS394), formed a coordinated
attack group and operated in conjunction with the commanding officer
of the TREPANG as group commander. During the latter part of the patrol the group consisted
of the SEGUNDO and the RAZORBACK with the commanding officer of the
SEGUNDO as group commander.

2. During her first patrol the SEGUNDO had no opportunity
to attack the enemy, her mission being primarily reconnaissance in
connection with major fleet operations in progress at the time. During
this patrol, however, her fighting spirit was well demonstrated by two
aggressive attacks which sent two large enemy AK's to the bottom and
crippled a large AP which was subsequently sunk by the RAZORBACK.
Typhoon weather was encountered, and on the night of 9 December a
mountainous wave and heavy lurch of the ship resulted in the port look-
out, SAUNDERS, G. H., F1c, V-6, U.S. Naval Reserve, while in the per-
formance of his duty, being washed overboard. Despite a thorough
search, he could not be located in the tumultuous seas. This regret-
table casualty is considered incident to war operations and one to which
no blame is attached.

3. Award of the Submarine Combat Insignia for this patrol
is authorized.

4. The Commander Submarine Force, Pacific Fleet, congratu-
lates the commanding officer, officers, and crew for this aggressive
and successful patrol. The SEGUNDO is credited with having inflicted
the following damage upon the enemy:

- 1 -

— page 111 —
SS398/A16-3 DECLASSIFIED
U.S.S. SEGUNDO (SS398)
Care of Fleet Post Office
San Francisco, California
26 March 1945
Serial (006)

From:
The Commanding Officer, U.S.S. SEGUNDO ($5398).
To:
The Commander in Chief, United States Fleet.
(1) The Commander Submarine Division FORTY-THREE
(2) The Commander Submarine Squadron FOUR.
(3) The Commander Submarine Force, Pacific Fleet.
(4) The Commander in Chief, United States Pacific Fleet.
Subject:
U.S.S. SEGUNDO (SS398) - Report of War Patrol Number Three.
Enclosures:
(A) Subject report.
(B) Track Chart (Comsubspac only).
(C) Supplementary Patrol Instructions (Comsubspac only.).
(D) Area Division Chart (Comsubspac only).
(E) Supplementary Communication Instructions (Comsubspac only).

1.
Enclosure (A), covering the Third War Patrol of this vessel
and operations of Task Group Seventeen Point Twenty-Four conducted in the
East China Sea during the period from 1 February 1945 to 26 March 1945, is
forwarded herewith.

FILMED
115153
DECLASSIFIED ART. 0445, OPNAVINST 5510.IC
BY 010.968
DATE 6/16/72

[SIGNATURE: J.D. FULP, Jr.]

— page 112 —
[STAMP: DECLASSIFIED]
U.S.S. SEGUNDO (SS398) - Report of Third War Patrol.

(A) PROLOGUE

        Arrived GUAM on 5 January 1945 from second war patrol. Refit
    satisfactorily accomplished by U.S.S. APOLLO and SubDiv 282 Relief
    Crew No. One. Excellent recuperation at CAMP DEALEY on windward
    GUAM; a big hand to those who, in the short space of six weeks, had
    constructed and organized CAMP DEALEY and made it almost luxurious.
        Lobes of low-pressure blower seized and some of the bearings
    froze on surfacing after first post-refit trim dive. Blower dis-
    assembled, removed from ship, cut taken on ends of lobes, bearings
    renewed, reassembled, and reinstalled on board.
        One day of the normal five day training period lost on
    account of the blower casualty, but an additional day of pack
    training more than made up for this loss. Trained by Commander
    T.M. DYKERS, ComSubDiv 282, who was of great assistance through-
    out the refit.
        Transferred five men and one officer to SubDiv 282 Relief
    Crew and received five men and one officer in return.

(B) NARRATIVE

        Name                    Rank        File No.        Number of War Patrols
                                            Service No.
    FULD, James D., Jr.     Comdr.      73638                   10
    BAISON, John E.         Lieut.      97780                   3
    FILTER, Frank C.        Lieut.      119495                  1
    AUBREY, Robert E., Jr.  Lieut.      165418                  3
    BROZO, John K.          Lt(jg)      275465                  3
    MCLAUGHLIN, John P.     Lt(jg)      229208                  2
    HAHN, Jack A.L.         Ensign      257732                  3
    JOHNSON, Lewis R.       Ensign      257802                  3
    ROSE, Mac C.            Ensign      312685                  2
    HORGAN, Victor W.       Ensign      338229                  2
    RUSSELL, Edward A.      CTM(PA)     381 07 61               8
    CLARK, William V.       CTM(AA)(T)  321 31 92               11
    MARVEL, Paul T.         CQM(T)      316 11 45               3
    DOWNS, James T.         CMoMM(PA)   375 74 03               11
    VON BEHREN, Arthur C.   CMoMM(PA)   375 75 73               13
    MATHEWS, David G.       CEM(AA)(T)  233 99 58               6
    PECK, Lewis E.          CPhM(T)     268 45 56               3

-1-                     ENCLOSURE (A)

— page 113 —
CONFIDENTIAL
Subject:
U.S.S. SEGUNDO (SS398) - Report of Third War Patrol.
1 February 1945
1630(K)
Underway for patrol area in company with SEACAT and
RAZORBACK, forming a coordinated attack group with senior
commanding officer in SEGUNDO. Escorted by U.S.S. DEMPSEY
until 2200.
6 February 1945
0345(1)
0605(1)
1200(I)
1856(1)
2310(1)
2320(1)
7 February 1945
0350(1)
0603(1)
NOTE:-
1200(1)
1851(1)
8 February 1945
0620(1)
1200(1)
1900(1)
Made radar contact (secondary pip) on YAKU SHIMA at
112,000 yards.
Dove for the day..
Position 29-48 N., 131-03 Ε.
Surfaced and commenced transit of COLNETT STRAIT, followed
by RAZORBACK and SEACAT at about 15 mile intervals. During
transit had almost constant APR contacts at 148 and 152 MCS,
but they appeared to be land-based.
Transit completed.
SJ contact at 3200 yards. Had been keying the SJ, making
several sweeps every five minutes. Although we did not sight
this object, we were sighted by him, as we had some little
trouble shaking him at 15 knots. Lost the pip after a half
hour at 6100 yards. From the picture as presented, it appeared
that we might have had a patrolling submarine, possibly a midget,
so sent advice to RAZORBACK and SEACAT.

by SJ radar.
Exchanged recognition signals and callssigns with SEACAT
Dove for the day.
The Task Group is patrolling as a pack; that is, in
accordance with Patrol Plan ABLE of Enc. (C) to this report.
Position 31-32 N., 129-04 E.
Surfaced.

Dove for the day. It is rough, sea state six, and
visibility bad.
Position 30-28 N., 129-08 E.
Surfaced. Throughout the ensuing night had many cloud
contacts on the SJ and passed through many heavy rains. Seas
are beginning to abate.
-2-
ENCLOSURE (A)

— page 114 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of Third War Patrol.

9 February 1945

0130(I)         Dove for 155 MCS contact which was later determined to be
                land-based; probably located on UJI GUNTO.
0220(I)         Surfaced.
0232(I)         APR contact at 76 MCS, probably located on KOSHIKI SHIMA.
0625(I)         Dove for the day. Visibility now good. KOSHIKI SHIMA and
                UJI GUNTO in sight most of the day.
1200(I)         Position 31-45 N., 129-13 E.
1438(I)         CO 2 content of the boat considerably bolstered by accidental
                release of a fire extinguisher.
1857(I)         Surfaced. Headed west at standard speed to get clear of
                the rest of the pack before transmitting weather report.
2150(I)         After waiting about two hours to get a clear circuit,
                delivered weather report to GUAM without difficulty.
2307(I)         Exchanged recognition signals and calls with RAZORBACK
                via SJ radar.

10 February 1945

0628(I)         Dove for the day.
0654(I)         Surfaced to clear lanyard from gun trunk door.
0659(I)         Dove. UJI GUNTO and KOSHIKI SHIMA now in sight. Main-
                taining continuous high periscope patrol.
1200(I)         Position 31-28 N., 129-10 E.
1858(I)         Surfaced.
2215(I)         Sighted white light bearing 060°(T), believed to be
                TSURIKAKE SAKE, distance about 45 miles.

11 February 1945

0450(I)         SJ contact bearing 040°(T) range 13,000 yards. Exchanged
                calls and recognition signals with SEACAT.
0619(I)         Dove for the day.
1200(I)         Position 31-29 N., 129-06 E.
1858(I)         Surfaced. Took Pack on a diversionary trip to western
                edge of area between latitudes 32° N. and 33° N.
2235(I)         Slight interference on SJ from direction of DANJO GUNTO.

12 February 1945

0639(I)         Dove for the day.

                                        -3-                     ENCLOSURE (A)

— page 115 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of Third War Patrol.

1200(I) Position:- 32-33 N., 127-22 E.
1908(I) Surfaced.
2131(I) Discontinued search in this area and headed back to scheduled
area between FUKAE SHIMA and KOSHIKI RETTO. Orders to the Pack to
this effect have been delivered.

13 February 1945

0623(I) Dove for the day.
1200(I) Position:- 32-03 N., 129-10 E.
1858(I) Surfaced. Cleared area to send weather report.
2105(I) Commenced sending weather report. No trouble in transmission;
got a receipt at 2120. Headed back toward scheduled area.

14 February 1945

0015(I) SJ contact bearing 142°(T), range 10,950 yards. Receiving
SJ interference from this pip.
0026(I) Exchanged recognition signals and calls with RAZORBACK.
0030(I) Lost contact.
0626(I) Dove for the day.
1200(I) Position:- 31-55 N., 128-55 E.
1858(I) Surfaced.
2059(I) At 100 fathom curve in southwestern approaches to NAGASAKI.
No string of white lighted fishing boats as previously reported by
other subs in this area. Commenced moving to new area west of FUKAE
SHIMA.

15 February 1945

0000(I) While shifting patrol area, received contact report from
RAZORBACK which was cancelled twenty minutes later, having proved
false.
0030(I) When about halfway between DANJO GUNTO and FUKAE SHIMA,
received contact report from SEACAT on three small targets, range
10,000 yards. We had picked up SEACAT's radar interference a few
minutes before, bearing dead ahead, about 268°(T). Our position
checked with that of SEACAT.
0055(I) When contact appeared imminent, changed course to north in
order to be sure of making contact and to gain position on the
flank opposite SEACAT.
0116(I) Picked three small pips, bearing 280°(T), range 11,600 yards,
out of a multitude of rain pips on both PPI and A-scope. Very
doubtful. Raining now, with heavy black clouds all around.

-4- ENCLOSURE (A)

— page 116 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS396) - Report of Third War Patrol.

0117(I) Went to battle stations. Lost the three small pips.
0118(I) Received "Am attacking" from SEACAT. She had not yet trans-
mitted a course and speed.
0146(I) Three explosions spaced eleven or twelve seconds apart.
0203(I) SEACAT reported attack completed.
0235(I) Having so far failed to gain a definite contact, secured
from battle stations. It appeared ships were not suitable torpedo
targets; SEACAT was not able to identify them. Kept tracking
stations manned.

0250(I) Secured from tracking stations.
0400(I) Dove for the day toward day's patrol area.
0609(I) First plane contact, day or night, since starting this patrol.
0805(I) Sighted twin-engined unidentified land plane flying low, range
five or six miles.
1200(I) Position:- 32-38 N., 128-03 E.
1658(I) Surfaced.
2145(I) Gave instructions to Pack for interception of Task Force
reported by China planes near FORMOSA. Patrol stations assigned
as follows:
SEGUNDO:- 32-17 N.; 126-50 E.
SEACAT:- 32-19 N.; 127-24 E.
RAZORBACK:- 31-50 N.; 126-44 E.

16 February 1945
0300(I) Changed positions of Pack patrol stations to the following:-
SEGUNDO:- 33-48 N.; 128-29 E.
SEACAT:- 34-00 N.; 128-17 E.
RAZORBACK:- 33-36 N.; 128-39 E.
0628(I) Dove.
0915(I) SHIP CONTACT No. 1. JP and JK sound gear picked up screws
bearing 190°(T). Went to battle stations and at 0917 sighted
fairwater of an Item class submarine. Target presented a 30° port
angle on the first look, on second look a port angle of 35° and
on third look a port angle of 70° with the range 6,200 yards. He
appeared to be making about 12 knots, and was either headed for
SASEBO, or for a land-fall on SHIRO SE thence toward IKI SHIMA.
It was doubtful whether or not we could have made a success-
ful end-around. He was keeping a high periscope watch and was
travelling with islands close on his starboard side. We particu-
larly wanted to remain undetected to-day on account of the Task
Force, so did not try an end-around.
0952(I) Secured from battle stations.

-5- ENCLOSURE (A)

— page 117 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of Third War Patrol.

1200(I)             Position:- 32-54 N., 127-58 E.
1859(I)             Surfaced. Continued toward assigned patrol position.
2100(I)             Reached assigned position. Commenced patrolling on course
                    040°(T) and reverse.

17 February 1945

0008(I)             Sent orders to Pack shifting patrol positions to northward
                    25 miles. New positions are as follows:-
                    SEACAT:- 34-25 N.; 128-18 E.
                    SEGUNDO:- 34-14 N.; 128-28 E.
                    RAZORBACK:- 34-02 N.; 128-40 E.
0200(I)             Two lightships, or white-lighted fishermaen, are occupying
                    our spot. Many fishing boat and small maru contacts the rest of
                    the night; most of the traffic moving on course 280°(T) or reverse.
                    We were either at tracking stations or battle stations about half
                    the time.
0306(I) & 0310(I)Sighted navigational lights on KO TO and SHIMONO SHIMA.
                    Dove for the day. During this day we had innumerable fishing
                    vessel and small maru contacts.
1200(I)             Position:- 34-09 N.; 128-31 E.
1858(I)             Surfaced in a flat calm sea, second quarter moon. SJ radar
                    out of commission temporarily - advice to this effect was sent to
                    SEACAT and RAZORBACK. Visibility was unlimited; estimated that
                    heavy ships could have been seen at 25,000 yards.
2040(I)             SHIP CONTACT No. 2. Sighted ship with binoculars with a
                    small port angle on the bow headed in an easterly direction toward
                    us. A few minutes later the PPI was back in commission but the
                    range unit remained out. Range was approximately 12,000 yards.
                    Ship which resembled a destroyer proceeded on a steady course until
                    he had passed the white-lighted fishing vessels where he lay-to.
                    We got the SJ back in full commission while tracking this
                    vessel.
                    The peculiar actions of this ship indicated that he was an
                    advance screen for more important units, so we did not attack. He
                    continued to lie-to in the same position and we kept him under
                    surveillance at ranges varying from 14,000 to 16,000 yards.
                    At about 2330 RAZORBACK made radar contact on this ship at
                    18,000 yards and sent contact report, asking also if it was SEGUNDO.
                    To avoid unnecessary radio transmissions we had not reported our
                    radar back in commission yet, wanting to test it out for a while
                    before doing so. However, we now had to a reply to RAZORBACK's
                    interrogation, so sent the single word "negative".

-6-                 ENCLOSURE (A)

— page 122 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of Third War Patrol.

Both these reports were sent without any difficulty whatever.
Both were handed to CTF 72.
Stayed on the surface making best speed toward our desired
destination until
1156(I) when an SD contact at eight miles forced us down. Apparently
their DF equipment is working all right.
1200(I) Position:- 31-12 N, 129-10 E.
1857(I) Surfaced in a rough sea.
2301(I) Exchanged recognition signals with unidentified source of
SJ interference to the southwest; believed to be SEACAT
patrolling the area south of latitude 30°-23' north.

26 February 1945

Took patrol station on east-west courses from eleven to thirty
miles due west of KUCHINO YERABU ISLAND. There is a
northwest coast of this island that resembles a ship at night.
0604(I) Dove for the day. The sea had calmed down by now.
1200(I) Position:- 30-30 N., 129-46 E.
1251(I) Sighted one MAVIS at about 3000 feet on course 230°(T). He
passed directly overhead but gave no indication of having seen us.
1320(I) Sighted one plane, too distant to identify, course about
230°(T).
1349(I) Surfaced. Commenced opening out to send scheduled weather
report.
1908(I) APR contact at 157 MCS weak and sweeping. According to
BATFISH, Jap subs carry radar of this frequency. However, there
are a lot of shore based radars around here employing many different
frequencies. Swung ship a couple of times and determined bearing
to be 060°(T) to 070°(T), which is the bearing of IWO SHIMA. The
contact appeared to be land-based.
2100(I) Commenced sending weather report. Transmission required
nearly an hour. CTF 72 took the message.
2343(I) APR contact at 153 MCS, weak and sweeping. We are suspicious
of these frequencies since BATFISH report. Closed the direction
of the contact but it did not get any stronger, nor was a ship
contact made.

27 February 1945

0615(I) Dove about 15 miles west of KUSAKAKI SHIMA and set course to
pass between that island and UJI GUNTO.

-11- ENCLOSURE (A)

— page 123 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of Third War Patrol.

0758(I)          SHIP CONTACT No. 5. Pinging bearing 014°(T). Sighted smoke
                 at 0815 and two tall masts at 0828. Soon thereafter sighted two
                 tall stacks in conjunction with the masts. Bearings which had
                 been steady for a while, now commenced hauling right.
                      Pulled a full bell on the normal approach course for fifteen
                 minutes, then saw that we weren't closing much. Could make out the
                 masts of two smaller ships in addition to the transport. There
                 were three escorts.
                      Did not have much data on target course and speed but believed
                 he was headed southeast at about 11 knots.
                      Our proximity to islands made an end around long and diffi-
                 cult but surfaced and started one at 0949. Kept about 16 miles from
                 KUSAKAKI while working around it to the south and eastward.
                 Visibility was unlimited.
                      Since we had no real dope on convoy course and speed, we
                 had only conjecture to go by. Convoy could have been going in any
                 of the following three directions:-
                      (1) From KUSAKAKI eastward toward KAGOSHIMA KAIWAN.
                      (2) From KUSAKAKI southeastward toward COLNETT STRAIT.
                      (3) From KUSAKAKI southward toward the NANSEI SHOTO.
                      At 1130, had an SD contact at 15 miles which remained steady
                 for a couple of minutes, then started closing. Plane was sighted
                 by port lookout bearing 270° relative, position angle 6°, at a
                 range of 12 miles.
                      Dove when the plane had closed to 7 miles. Plane was a MAVIS.
                      At 1138 one bomb not very close.
1200(I)          Position:- 30-30 N., 129-16 E.
                      At 1215 came up to periscope depth, all clear.
                      At 1245 another bomb explosion, not close, nothing in sight,
                 but it is now hazy.
                      At 1348, all ideas of further surface running were squelched
                 by the appearance of four RUFES, which began a systematic search
                 of the vicinity. Planes flew in a close column about one hundred
                 feet off the water. They were on course 240°(T) when first sighted and
                 seemed to search on legs of about ten miles, 240° and 000°, working
                 to the north westward.
                      At 1347, it looked like they were going to pass overhead so
                 went to 175 feet. At this time it was seen that the planes were
                 not RUFES but KATES and what we had mistaken for floats were in
                 fact torpedoes. Their low search altitude indicated some sort of
                 underwater detection devices.
1430(I)          At periscope depth, all clear but quite hazy.
1559(I)          Sighted one KATE, with torpedo, to the westward about ten
                 miles.

                                        -12-          ENCLOSURE (A)

— page 125 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of Third War Patrol.

0200(I) APR contact at 153 MCS; looked like plane.
0205(I) Contact "grew" very quickly, indicating it was air-
        borne.
0244(I) Surfaced.
0350(I) APR contact at 153 MCS, weak, being keyed.
0401(I) Above contact became steady and strong.
0402(I) Dove. Believe he spotted us.
0510(I) Surfaced. Had two APR contacts at 153 MCS, one was nearly
        saturated and being keyed sporadically while the other was weak
        and being keyed regularly. Looked like they were working to-
        gether so stayed on the surface to see what would happen.
0517(I) Both contacts disappeared.
0610(I) Contact came back in at 153 MCS, weak.
0617(I) Above contact increased from a weak signal to a strong
        signal in about thirty seconds. Bears out our theory that they
        can vary their power output.
0617(I) Dove for APR contact and submerged patrol off FUKAE SHIMA.
1200(I) SJ range on plane while diving - 12,000 yards.
1930(I) Position:- 32-26 N., 128-31 E.
        Exchanged recognition signals and call signs with RAZORBACK
        via SJ radar.

3 March 1945

0355(I) Sighted floating mine, barely afloat, in phosphorescent
        wash of ship, port side. Estimated distance from side - twenty
        feet. Position:- 31-50 N., 127-45 E.
        Mine was barely visible so did not go back to look
        for it.
0618(I) Dove for submerged patrol west of DANJO GUNTO.
0926(I) SHIP CONTACT No. 6. Sighted smoke, then masts, bearing
        251°(T). Target turned out to be hospital ship, properly
        marked and steering a steady course of 045°(T) at 14 knots.
        Identified as TAKASAGO MARU (AH2). Took several photographs.
        Position:- 31-59 N., 127-47 E.
1200(I) Surfaced.
1906(I) Sent message number seven to ComSubsPac requesting seven
        day extension in area preferably north of latitude thirty-four
        north. Advised SEACAT and RAZORBACK of this over the patrol
        frequency.
2130(I) Dove for submerged patrol southeastward of SAISHU TO.

4 March 1945

0614(I) Dove for submerged patrol southeastward of SAISHU TO.

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CONFIDENTIAL

Subject:
U.S.S. SEGUNDO (SS398) - Report of Third War Patrol.

lights whatever. Some were undoubtedly picket or patrol boats.
Only four were actually sighted by us.

6 March 1945

0611(I)           Dove for submerged patrol off TSUSHIMA Is.
1200(I)           Position:- 33-56 N., 128-22 E.
1300(I)           Sea has gotten rough. Started running at 90 feet, taking
                  looks every fifteen minutes.
1600(I)           Sea has calmed down. Maintained continuous periscope
                  watch.
1919(I)           Surfaced. Headed up for KINGO RETTO.
2211(I)           Made radar contact on first of two patrol boats at
                  10,000 yards. Thought to be patrols instead of fishermen
                  because we usually pick up the latter between 7,000 and 8,000
                  yards. Fishermen usually track at speeds from 3 to 6 knots,
                  whereas these two vessels tracked at zero knots. Worked around
                  them.
2320(I)           SHIP CONTACT No. 7. TORPEDO ATTACK No. 1. Made
                  contact on single ship bearing 250°(T), range 13,900. Commenced
                  tracking and started approach. Knew target was small but decided
                  to chance an attack. Target tracked on course 115° at 9 knots,
                  then on course 080° at same speed. We were not able to
                  switch on him until range had decreased to 9,000 yards.
                  Target came into view as a blob on the horizon at 2300
                  yards and could be seen well at 1500 yards. Looked him over
                  carefully for a minute or two then at 2355 commenced firing
                  first of four torpedoes using TBT bearings and point of aim;
                  spread, range at first shot 1300 yards and at last shot 1100
                  yards; depth setting six feet. Sea was state four, rough, but
                  not much swell because of the confined waters. Torpedoes were
                  fired directly down sea.
                  All torpedoes missed. This in spite of the fact that
                  solution of torpedo problem had checked perfectly since lobe-
                  switching had been begun.
                  Target, which was a small engines aft AK of the SUGAR
                  ABLE (c) or SUGAR CHARLIE type, gave no indication of having
                  sighted either the submarine or the highly phosphorescent
                  torpedo wakes. There were many porpoises in the vicinity and
                  he probably took the torpedoes to be porpoises.
                  The sea was too rough for gun attack.

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— page 129 —
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Subject: U.S.S. SEGUNDO (SS398) - Report of Third War Patrol.
---
Tracked this target until 0130.
Tried several times to-night to raise SEACAT by radio with-
out success.

8 March 1945

0136(I) Lost small ship we had been tracking and commenced clearing
confined waters at moonrise at 0158.
0608(I) Dove for submerged patrol east of SAISHU TO.
0939(I) Sighted three FRANCES aircraft which remained in the
vicinity for forty-five minutes.
1200(I) Position:- 33-36 N., 127-52 E.
1539(I) Sighted high peak on SAISHU TO at a range of 60 miles.
1923(I) Surfaced and headed for the YELLOW SEA to patrol in
accordance with ComSubPac dispatch 040612 of March approving
request for seven day extension.
At 2200 received message from TENCH (CTG 17.22 - BOXERS)
saying they would not be north of latitude 34° north until the
seventeenth. Made decision, based on this information, to continue
patrol in East China Sea north of thirty-four north. If we had
gone to the YELLOW SEA, we would have had only two days
time and that in an area with which we were not familiar. We
have become pretty well acquainted with the EAST CHINA SEA, have
a pretty good idea where the traffic is moving, and will be able
to spend more time actually patrolling.
2200(I) Sighted two steady bright white lights, milling around
like fishing trawlers.
During the night tried, without success, to communicate
with SEACAT and TENCH. Wanted to remain in the EAST CHINA SEA,
and to advise SEACAT of this.

9 March 1945

0608(I) Dove for submerged patrol between HAKU TO and TSUSHIMA Is.
0641(I) Sighted trawler.
0740(I) Sighted subchaser patrolling back and forth. Looked like
he might have been maintaining visual distance from the trawler.
1200(I) Position:- 34-01 N., 128-12 E.
1315(I) Sighted two-masted schooner. No Japanese flag showing.
1932(I) Surfaced. Headed up for REISUI KAIWAN. The sea was state
five.
2315(I) SHIP CONTACT No. 9. Made SJ radar contact on single ship,
bearing 004°(T), range 11,990 yards. Target was small, probably

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— page 130 —
CONFIDENTIAL
Subject: U.S.S. SEGUNDO (SS398) - Report of Third War Patrol.

2335(I) another SUGAR CHARLIE, and tracked on course 255°(T) at 10 knots.
     SHIP CONTACT No. 10. TORPEDO ATTACK No. 2. While tracking
     first target, made SJ contact on single ship bearing 270°(T),
     range 16,000 yards. Commenced approach on this ship as it
     appeared to be bigger than the first. Target tracked on course
     060°(T) at 7 knots and passed the no. 1 on opposite course about
     1000 yards. Both ships passed some 3 miles south of SEISON TO.

10 March 1945
0120(I) Fired four torpedoes from bow tubes at target, a medium AK,
     flush deck, steering a steady course of 060°(T) at 7 knots. Had
     tracked for 1½ hours and solution checked perfectly. Mean torpedo
     run 1050 yards, track 85° port, gyros 15° left, depth setting 6 feet,
     sea state 4, moderate swells short length, torpedoes fired down
     sea. Point of aim spread by forward TBT. Target was burning
     side lights. All torpedoes missed. No. 2 torpedo may have run
     erratic according to the O.O.D.
     During the approach phase submarine crossed target track
     ahead, both to take advantage of the dark background of the
     islands KATSU TO and YOKUCHI TO, and to be able to fire down
     sea. Submarine maintained bare steerageway about 3 miles
     off KATSU TO and waited for target to "cross its sights". Target
     should have sighted submarine by naked eye at 2000 yards
     if he had had any lookouts, but apparently he did not. He must
     have thought we were a fishing vessel.
     Submarine chose to attack on the surface to avoid having
     to dive in confined waters with strong currents. Target gave
     no indication of having sighted submarine after attack.
     Reasons for misses unexplained. Target was definitely a
     good size ship, measuring at least 350 feet in length by binoculars
     and radar. All fire control data and gear, and gyro-setting gear
     were checked and found to be O.K. Assuming that no. 2 torpedo
     ran erratic, then No. 3 and No. 4 should have hit. Post-mortem
     plot shows that at least one and possibly three torpedoes should
     have hit.
0612(I) Dove for submerged patrol.
1200(I) Position:- 34-08 N., 128-32 E.
1925(I) Surfaced. Headed for the REISUI KAIWAN.
2232(I) Encountered the first of about twenty fishing vessels and/or
     patrols.

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