U.S.S. CERO (SS-225) — war patrol report SS-225_CERO_Part1.pdf

— page 4 —
2- USS CER0 (SS 225)

Only two ship contacts were made, one a cruiser and the second a destroyer. Both the targets were cutting the water at high speed and could not be attacked. On 1 January 1944, she left the area, arriving in Milne Bay on 12 January for a refit by USS FULTON.

CER0's third patrol was in the same area, beginning on 4 February. Her first contact on 10 February at first looked promising, but proved to be a convoy made up of ships too small for a torpedo attack. Six days later CER0 met a single ship with two escorts and fired four torpedoes. Although she had to dive, one timed hit was heard.

The next day she contacted a similar convoy and attacked with six torpedoes. Her target, a medium freighter, was seen to sink by USS PETO, which had been trailing the same convoy. The three escorts made a haphazard counter-attack but caused no damage.

Shifting to a new area, the Palau-Hollandia traffic route, CER0 contacted two ships with two escorts. She concentrated her first attack on the first ship, getting one hit which stopped the freighter. After the counter-attack by the escorts, she scored again from long range. On a third long-range attack all her torpedoes missed, and with none left, she sent contact reports and proceeded to Brisbane, arriving on 2 March. The Submarine Combat Insignia was awarded for this war patrol.

After departing Brisbane and conducting training exercises enroute, CER0 slipped out of Milne Bay on 3 April 1944, for her fourth war patrol. Her patrol area was in the vicinity of Halmahera, but the hunting proved fruitless and the submarine was ordered to Seeadler Harbor, Manus, for refueling before continuing her patrol. She left Manus on 11 May and returned to the Halmahera area, where on 21 May, she contacted a medium freighter and fired four torpedoes for one hit, damaging the target. Sighting the torpedo wakes, the freighter tried to avoid them unsuccessfully, and charging down the wake, the escorts gave CER0 a thorough working over, although they did not damage her.

Two days later the submarine fired six torpedoes into a heavily-escorted convoy, for two hits in each of two medium freighters. The escorts and air cover immediately counterattacked, forcing CER0 to dive before she could assess the damage. The patrol ended at Seeadler Harbor on 2 June, 60 days after it was begun. The Submarine Combat Insignia was awarded for this war patrol.

The refit was completed on 17 June 1944 and, after an eight-day training and loading period, CER0 departed for her fifth war patrol, heading for Mindanao, Philippine Islands.

As soon as she entered her assigned area, the masts of a battleship, together with two escorts, were sighted, but could not be closed for an attack. Sending out contact reports, she continued her search, but no targets worth torpedoes presented them.

— page 5 —
3- USS CERO (SS 225)
selves until 22 July. Then one small ship with three escorts was sighted and attacked, with six torpedoes running under the targets.

A week later, as the sub was making an approach on a small trawler, she sighted a Japanese cruiser but was again unable to close for an attack. After several small ship contacts, two fairly large ships with three escorts crossed her path, and CERO fired six torpedoes at short range. Four of the missiles struck a tanker, which promptly sank. No further contacts were made and the patrol was terminated when the submarine arrived in Seeadler Harbor, on 14 August, proceeding from there to Brisbane, Australia for a refit. The Submarine Combat Insignia was awarded for the fifth war patrol.

The submarine departed from Darwin, Australia on 19 September 1944, for her sixth war patrol, conducted in the Mindanao and Sulu seas. The first part of the patrol was characterized by many aircraft and small boat contacts, none worth torpedoes. After 24 days she put in at Mios Woendi for voyage repairs and instructions for a special mission.

Taking aboard 17 tons of supplies and 16 Army troops, she departed on 17 October for Luzon, where she was to land the supplies and personnel to reinforce Philippine guerrillas. She was under orders not to attack escorted merchantmen, but on the 27th, two small craft were attacked with gunfire, damaged and driven ashore. After landing her reinforcements, the sub took aboard two U.S. aviators who had crashed on Luzon, an infantryman who had escaped from the Japanese after two years as a prisoner of war, and a twelve year old boy, son of a U.S. naval officer.

After getting underway again, the ship was attacked on 3 November by a Japanese submarine. The officer of the deck spotted the enemy sub when he accidentally broached during his approach, and successfully avoided the torpedo.

On the next day CERO was ordered to Beier Point, Luzon to stand life guard duty for air strikes on Luzon. No pilots were shot down during the mission, and on 7 November she left the area for Pearl Harbor. The patrol ended in Pearl Harbor on the 24th, after 72 days, and the Submarine Combat Insignia was again awarded.

Now due for an overhaul, CERO proceeded to the Mare Island Navy Yard at San Francisco, California, for an availability which lasted from 6 December 1944 until 26 February 1945.

On 6 February Lieutenant Commander Raymond Berthrong, USN, relieved Commander Dissette as commanding officer.

After leaving the yard, CERO spent nine days at Monterey, California, operating with planes engaged in anti-submarine exercises on 7 March she left for Pearl Harbor, where she received voyage repairs from USS BUSHNELL.

— page 6 —
4- USS CERO (SS 225)

Sailing to Guam, the submarine again received voyage repairs and refueled before beginning her seventh war patrol on 13 April 1945. Her first duty was on life guard station covering B-29 raids on Japan from 18 to 21 April. On the 19th she discovered two Japanese picket boats and sent one down with a torpedo attack. The other escaped in a heavy mist. On the 21st she was released from this duty and left for the northeastern coast of Honshu. On the morning of the following day she met two more picket boats and, after a 40-minute gun duel, sank one and left the other badly damaged.

Shortly after her attack on the picket boats, it was found that both preppellers were vibrating badly as a result of hitting some of the empty shell casings during the gunfire. If the ship was to continue on her patrol, repairs would have to be made at sea, a dangerous and difficult task when contact with enemy ships or planes might force her to dive at any time. Chief Boatswain's mate B. F. Miller and Electrician's mate 1/c J. M. Naylor volunteered for the job, even though they knew that they would be lost if the sub were forced to submerge while they were working.

Using shallow water diving masks, they succeeded in removing all the nicks from the propeller blades after working four hours on two successive nights with only "long-handle" underwear to protect them from the icy waters. The courageous and skillful work of these men enabled CERO to continue her patrol and to sink four more ships at a time when the enemy could ill afford to lose them.

For three weeks CERO patrolled her area, just a mile off the coast of the Japanese homeland. On the 29th she sank an unescorted medium tanker with one hit and on 4 May fired four torpedoes at three escorted freighters. The leading ship sank immediately, but the other two successfully avoided the torpedoes.

Another small freighter steaming alone was sunk with one torpedo hit on the 15th and on the 19th CERO left the patrol area, enroute to Guam. A deep sea trawler was encountered the next day and sent down with one torpedo hit. The highly successful submarine reached Guam on 27 May. The Submarine Combat Insignia was authorized for her seventh war patrol.

The eighth war patrol began on 27 June when the submarine left Saipan with Task Group 17.16, known locally as Berrow's Barnstormers. USS MORAY, LAPON, CARP and CERO made up the Task Group, with ANGLER and SEA POACHER in company.

After a week on life guard duty, CERO conducted a two-day sweep for picket boats with no results. She continued with her life guard services for the carrier strikes and, on 14 July, received word that three aviators had been shot down in Tsugaru Straits, the narrow, heavily-mined passage between Honshu and Hokkaido. In spite of enemy minefields, the sub ran into the

— page 8 —
35225/A16-3
Serial 06
16 November 1943.

DECLASSIFIED

From: Commanding Officer.
To: Commander-in-Chief, United States Fleet.
Via: (1) CO and Task Group 17.14 (Captain C.B. O'SHER, U.S. Navy).
(2) Commander Submarine Force, Pacific Fleet.
(3) Commander-in-Chief, U.S. Pacific Fleet.

Subject: U.S.S. CARO, Report of "ar Patrol Number 1.

Enclosure: (A) Subject report.
(B) Track chart of area for Consubpact.

1. Enclosure (A), covering the first war patrol of this vessel conducted in the Last China Sea and the Yellow Sea during the period 26 September, 1943 to 16 November, 1943 is forwarded herewith.

D. C. NITE.

DECLASSIFIED
BY: O.C. 2020
DATE: 3/12/43

DECLASSIFIED

— page 9 —
15 November 1943
SS225/AL6-3
Serial 06
CONFIDENTIAL

(A) Prologue.

Corr. issued 4 July, 1943 at U.S. Submarine Base, New London, Conn. Shakedown period; completed fitting out, sound tested; preliminary training; Newport test firing; installed chrome liners. 17 Aug. - 15 Sept., enroute Pearl Harbor, 13-16 Sept., refit at Submarine Base, Pearl Harbor, T.E. 16-23 Sept. - inel training period. Total training since commissioning: Fired 10 exercise torpedoes, made dummy mine plant, fired all guns. 23-25 Sept., loading. 26 Sept., ready for sea.

(B) Narrative.

Date: 26 Sept. 1943
Time: 1245 (V)
Departed Pearl in company with U.S.S. CAPTAIN C.B. LOCK, with YF escort. Captain C.B. LOCK in accordance Subpar. OPERATION ORDER 217-43. At dart. Escort turned back; parted company with LAFON. Proceeding in company with CAPTAIN C.B. LOCK, in company with CAPTAIN C

— page 11 —
1st ATTACK
SS225/A16-3
Serial 08
DATE: Oct. 10
TIME: 10:00
The group was now believed separated due above attack and probable cause. Group Commander ordered group for a cross Bungo - Truk route but this was cancelled by Consubpasc. C.20 proceeding independently to be in 2nd assigned group of squeres in area on 14 October.

1st ATTACK
12 02-25(I) 0227
Radar contact OK. true, 16,550 yards. 1000l.ht. (Lt. 29-00J., long. 137-23.). 3L.nted convoy consisting of 2DDS and 3AKs. Southerly course. Zigging radically. Closed range to about 10,000 yards, then tracked from area. Flamed on making submerged attack from east with convoy silhouetted by setting moon. The moon set before plot had been course. Therefore decided to radd away attack from west side of convoy. Visibility excessive for surface attack. Submerged on starboard (west) bow or convoy. Convoy zigged 100° away. Closed at standard speed. Convoy formation observed to be as follows: 1 large and 2 medium AIS. 1 DD in van, following by large AIS directly astern. One medium AIS sharp on port quarter of large AIS and 2nd medium AIS just about large AIS port beam. Another DD about 1000 yards astern of AIS. Then ran on large AIS had closed to 2500 yards and this AIS overlapped the 1st medium AIS, fired six torpedoes; one to run a quarter len th head of large AIS, three to hit, one a quarter length astern of large AIS, (at 100° of overlapping medium AIS), and one to pass a third long th astern of medium AIS (just inside bow of third AIS).

(3)

— page 12 —
15 Nov 1943
SS225/A16-3
Serial 08
CO: TID: TIAL
Date: Oct. 12
Time: 120 track on first AX, 116 track on second and 115 on third.
0517-53
0518-10
0518-16
0600
0740
0628
0545
0900
1120
1130

2nd A TACK
Commended approach on stopped AX; this took some time because AX apparently was drifting away from us, et a speed of about one and one half knots by T.D.C. DD circled AX at times, at others ran parallel to AX on our side, etc. DD would run out 2 or 3 miles from AX as if searching.
DD now running out away from target on opposite side. Mile cloisn wind shifted her et so that at 2000 yeacs the angle on the bow was 15° port.
Care seeen to be similar to Africa Iaru class, 9500 tons, but with tripod mast aft.

— page 13 —
15 November 1943.
SS225/A16-3
Serial 06
CO: FIDELITAL
Date: 12 Oct. 12
Time: 11:34-15
Fired 3 torpedoes, straight shots, torpedo run 1900 yards. All seen and heard to hit. AC came around firing gun and DD turned toward us.
1137
Vent to deep submergence - rigged for depth charge. Wrecked by running silent. Tool: 31 charges - much closer than the first attack. These were more numerous small explosions in addition to charges. These were believed to be gun fire.
1430
At periscope depth. AC now settled further, and back on even keel from hits near bow.
1432(about) Heard torpedoes running (not ours). Heard one explosion (probably torpedo). At this time a 'periscope observation showed both DD and AC frantically firing guns at the water. For depth charges back. (It was later decerned that DD firing at DD's caustics of this).
1525
Secured from battle stations after a 13 hour session. Decided to rest, feed and rest crew and cargo before going on a attack convoy.
1725
Target still in sight, stopped; lower in water; DD alongside.
1800
The group Commander now decided that we would continue to area. The next put in the air hatch, since A was a gunner with four torpedo hits.
1834
surfaced. Proceeding north to 25th parallel of latituac.
1948
C/C to 270 along 25th parallel, proceeding on two generators.
Oct. 13
Proceeding on surface.
1430(I)
Plane on radar, 11 miles.
1441
submerged.

(5)

— page 14 —
16 November 1943
SS225/A16-3
Serial 06
CO FIDMITAL

Date: 13 Oct. 13
Time: 1031
Surfaced.
Struck submerged object, probably log.
Believe it did not touch screws.
Sighted Felaar. Line bearings 242ft.
Sighted Voloato. Time bearing 242ft.
Discovered self tector in main motor suap
tanks. Cloored to 1/3 on port sheet.
Submerged.
Oil changed. Looks repaired. Sea casualty
ties.
Surfaced. 22 miles from Taaier. Time to make
assisted square tonight in time for
possible contacts.
Plane on radar 16 miles. 15
Surfaced. 16 miles at 10 miles es racar
224ft.
Surfaced. Redo no contact, although
CRITICAL LATER reported by visuel e contact
this data. GND did not receive GAVRAC's
suggested report.
Patroling submerged 12 hr group of
squares. Attacked 6 co. navigation with
GND and GAVRAC this data. Unsuccessful.
Passed through floating wreckage and fuel
oil slick about 3 miles across. This was
smoothly after entering Japan current.
Oct. 16 0236(1)
Oct. 17 1156(1)
Oct. 17 1410

— page 16 —
2227
: 2311
: 2330
: 02207(I)
: 0220-0330
: 0250

U.S.S. CERO (SS225)
PAROL REPORT
16 November 1943.

Received group signal from "freiler" meaning "enemy course 170". Just have missed first signal while submer. ed with DD in vicinity.
Sent out group check signal. Answered by SAD and GRAYBACK. CRAYC. using "Fireline" signal. Coincued close in the enemy probable course line through GRAYBACK area.
Received signal from GRAYC meaning "enemy in 10 mile square" nose concer is 27-45N, 124-252W.
This showed that GRAYC had made contact in late afternoon and was now 57 miles distant. Uncer.ay on 3 generators in pursuit.
Received signal from SAD meaning in 10 mile square moose came in 29-05W, 123-55W. This confirmed SAD's first enemy contact as to course. Showed possible 15-20 knot speed.
Retrolled across probable enemy course until tie of expected contact. Then retried again (1600r.) signalled enemy course until daylight.
Heard many distant uncer.ver explosions. It is no concer and on signalled enemy course line, sent signal meaning "net quere is enay inf" No cnsver.

(6)

— page 17 —
16 November 1943
SS225/416-3
Serial 08
CONTACT WITH
Data
Oct. 22
Time
0419
0716
1016
23
0520(1)
24
2300(1)
25
1625(8)
1105
1120
1620
2320
2322
(9)
CLOSURE (A)

— page 23 —
16 November 1943.
SS225/416-3
Serial 08
CO. FIDMITAL
Date: 9 Nov. 6
Time: 10
9 1600(I)
10 0735(T)

2697

— page 24 —
15 Nov 1943
SS225/416-3
Serial 08
CO FID: TIAL

Date: 14 Nov 1943
Rev: 1

14:23
14:40
13 1420

Nov. 16 0710(Y) Sighted escort plane.
0935(Y) Moored to Bushnell, ltdway Island.

(16) 16

— page 26 —
32225/ALG-2/
Serial 08
CO FLIGHT
(F) Ship Contacts.

No.: Time : late : lat. : long. : type(s): name & special contact: remarks
1: 10225(-9): 12 Oct.: 20-00H : 17-23T : Convoy : 16,500 : 195 T : radar : (1) 9500 : (2) 1000 : (3) 1000 : (4) 1000 : (5) 1000 : (6) 1000 : (7) 1000 : (8) 1000 : (9) 1000 : (10) 1000 : (11) 1000 : (12) 1000 : (13) 1000 : (14) 1000 : (15) 1000 : (16) 1000 : (17) 1000 : (18) 1000 : (19) 1000 : (20) 1000 : (21) 1000 : (22) 1000 : (23) 1000 : (24) 1000 : (25) 1000 : (26) 1000 : (27) 1000 : (28) 1000 : (29) 1000 : (30) 1000 : (31) 1000 : (32) 1000 : (33) 1000 : (34) 1000 : (35) 1000 : (36) 1000 : (37) 1000 : (38) 1000 : (39) 1000 : (40) 1000 : (41) 1000 : (42) 1000 : (43) 1000 : (44) 1000 : (45) 1000 : (46) 1000 : (47) 1000 : (48) 1000 : (49) 1000 : (50) 1000 : (51) 1000 : (52) 1000 : (53) 1000 : (54) 1000 : (55) 1000 : (56) 1000 : (57) 1000 : (58) 1000 : (59) 1000 : (60) 1000 : (61) 1000 : (62) 1000 : (63) 1000 : (64) 1000 : (65) 1000 : (66) 1000 : (67) 1000 : (68) 1000 : (69) 1000 : (70) 1000 : (71) 1000 : (72) 1000 : (73) 1000 : (74) 1000 : (75) 1000 : (76) 1000 : (77) 1000 : (78) 1000 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— page 32 —
1. Attach Data.
: (Torpedo Attach Report Form)
: U.S.S. CERO
: TORPEDO ATT. CH #2
: Petrol #1
: Time 1134(1)
: Date 12 Oct. 1943
: Lt. 28-50, Lon. 137-20
: Target Drt. - Deringo Inflicted
: Description: One freighter (AK) sailor to Africe Ieru class, 9500 tons, but with tripod mast aft. Target clearly hit with one torpedo and stopped by attack #1. Corrected by Auri class DD.
: Contact - periscope.
: Viability - Outer clear, slight haze.
: Ship Sunk: - - -
: Ship probably Sunk: Africe Ieru class freighter, 9500 tons. The Coroanding Officer is of the opinion that this ship can't sink. Auri class it could not survive 4 torpedo hits.
: Deringo determined by: Hit with three (3) torpedoes (seen and heard), having previously been hit by one (1) (seen heard). Target remained stopped after this attack, settling over in water by sunset. Auri class DD alongside t sunset.
: Target Dret 30 feet. course - stopped speed - 0 Range 1900 yds.

: On Ship Data
: Speed - 3 Lts. Course 100°C. Depth 63 feet Angle (track) 15 port.
: Fire Control and Torpedo Data
: Type Attach - Deryli hit periscope approach. Used TDC. Divergent spread, with TDC target bearing held on periscope bearings.

(24) E'CLOSURE (A)

— page 39 —
15 November 1943.
SS225/16-3
Serial 08
CONFIDENTIAL

swaps in the motor room bilges. Some bolts were not hand tight.

Bilge water level had been above these connections for the first time during the previous day's depth charge attack, and salt water had leaked in.

These lines were not disassembled after CERO was commissioned. Therefore the ship was delivered by Electric Boat Co. in this condition.

Thickened connections; renewed oil. Remained reduction gears; no evidence of salt water on gears. Tool centrifuge reading; continuously for next 10 hours; no more salt water found.

(2) Casualty: to 4°50 c.r. gun foot firing mechanism. After the 16th round the foot firing mechanism failed to function. Shots 49 and 50 were fired by violently jerking the hand firing lever. (Gun could not be fired accurately by this method).

It is believed the foot of the gun jammed the firing lever or the sear which caused stiffness in centre mechanism. After gun jam cooled, the mechanism functioned normally. Further investigation for inadequate clearances will be made during refit period.

(I) Radio.

No essuelites, or unusual performance. No serials missed.

Co. enters on Helio Track:

9090 X no. is poor, signal strength varied, frequency varied. 4525 X and 14390 X: - note is good, but these frequencies could not be heard over 2000 miles from Pearl. Helio could not be heard at all while in Yellow sea during early November. X is in strength 5 in same area.

(II) Radar.

1. Loose connection on the transmitter pulse jack. (J7) caused race to jitter, and finally disappear.

(31)

— page 40 —
16 November 1943
SS225/16-3
Serial 06
CO. FD. MLL

(1) Reader, Cont'd.

2. The neon voltage control bulbs were frequently blown because of variation in line voltages. Securing the battery charge caused the radar motor generator to fluctuate badly. The running on ships' e.g. main of the battery or interruption of current evidently caused failure of neon bulbs due to sudden increase in line voltage. The failure of neon tubes oil-injected effect of the timing control.

3. Hydrant motor (blower) used interference on the screen.

4. Performances considered exceptional were contacts on 3 convoys at ranges as follows: 20,000 yards, 1,500 yards, 16,000 yards.

(2) Sound gear and sound conditions.

Sound conditions in October and November were poor in the East China sea and the Yellow Sea.

(3) Density layers.

One heavy density layer noted:
Temperature drop from 160 feet to 200 feet, 12°.
Time: 1:00, -10 tide.
Date: 7 Oct. 1943.
Lat. 34-45, Long. 153-25.

(4) Health, Food and Habitability.

(c) The crew is in illness excepting a few colds.
(b) One lookout experienced a sprained ankle on jumping below on a dive to escape a plane.
(c) Food was good. A better was carried and proved well worth its weight in improved v. r. r. of food.

(5) Personnel.

Personnel performed very well under combat conditions. This was particularly outstanding since this vessel was commissioned only 3 months before she made her first torpedo attack.

(32)

— page 41 —
15 November 1943.
S: 225/10-3
Sorial 08
CO.TIDETIL

(R) : [Lies Steamed - Fuel Used.
Pearl to area
In area
Area to. [day
(5) : [Duration.
Days enroute to area
Days in area
Days enroute to base
Days submerged

(T) Factors of Endurance Retaining.
Torpedoes
Number
6
Fuel
Gals.
6,962
Provisions
Days
30
Personnel Factor
Days
10
Limiting factor that percol - fuel.

(33) : CLOSTER (L).

— page 42 —
15-14/2/-16-3/FE161 SUBLIE DIVISION: CDR J. MURRAY FORTY TWO
Serial 025
Care of Fleet Post Office,
San Francisco, California,
15 November 1943.

FIRST REPORT TO:
CDR's Report of
First War Patrol.

From: The Commander Submarine Division 142.
To: The Commander Submarine Force, Pacific Fleet.
Via: (1) The Commander Submarine Force, Pacific Fleet,
    Subordinate Command, [draft].
    (2) The Commander Task Group 17.14.

Subject: U.S.S. CDR (55225) - Report of First War Patrol - Contents on.

1. The first war patrol of the CDR lasted for fifty-two days, twenty-nine of which were spent in enemy controlled waters. On this patrol the CDR was a unit of a coordinated attack group and this report is forwarded via the Task Group Commander for such contacts as may be desired covering CDR's actions relative to this special Task Group.

2. The CDR had six contacts with the enemy, four of which were twenty of torpedo fire. Three successful torpedo attacks were made and one contact was engaged with gunfire. A total of eighteen Task 14-3a torpedoes were fired and nine hits were observed on board.

3. ATTACKS

(a) Attack Number 1, October 12 - A night radar contact followed shortly thereafter by visual sighting of a convoy consisting of one large freighter and two medium freighters escorted by two destroyers. Visibility conditions precluded a night surface attack so position was attained for a submerged attack at dawn. At range of 2,500 yards and with large air overruns the second medium A-1 six torpedoes were fired on tracks of 120 - 115 degrees with spread applied by periscope. One hit was observed on the large freighter and two hits were heard which were believed to be on the medium A-1. From periscope observations about three hours later it is believed that an A-1 similar to TOYOTA 1-1U class sunk as a result of this attack.

(b) Attack Number 2, October 12 - This was a follow up attack on the large freighter identified as similar to the A-1. A-1U class which had been stored by one torpedo hit on

— page 45 —
A16-3
Serial 0152.
CONFIDENTIAL
SECOND INDORSER TO
CERO's Report of
First War Patrol.
FROI:
The Commander Submarine Force, Pacific Fleet.
Subordinate Command, Navy No. 1504.
To:
The Commander Submarine Force, Pacific Fleet.
Via:
The Commander Task Group 17,14.
Subject:
U.S.S. CERO (SS225) - Report of First War
Patrol - Comments on.

1. Forwarded concurring in the remarks of the
Commander Submarine Divison 142.

2. This was an excellent patrol and the remarks of
the task group commander after analysis of the individual
reports of the three submarines of this patrol is due to
group coordination and how much the restrictions inevitable
in any group attack affected the possible operations of CERO
in the vicinity of the enemy will no doubt be covered in the
task group commander's report.

3. The Coordinating Officer, officers and crew of
the CERO are congratulated on an excellent first patrol.

J. B. LONGSTAFF.
Copy to:
CSD 142
CO, USS CERO.

— page 46 —
1- FREICHER (TOTTOFI MUN cl. ss) - 5,573 tons

D.A.H.A.G.B.D

1 - Nevel auxiliary (MALYA cl. ss) - 15,620 tons
1 - Transport (class unknown) - 10,000 tons
1 - Freighter (unknown class) - 8,000 tons
1 - Petrol Boat - 150 tons

TOT:Lt: 33,570 tons

* NOTE: The MALYA was identified from Jane's Fighting Vessels 1942, after the return of the CERO to port.

Distribution and authentication:
on following p.ce. - 1 -

C. A. LOCWCCO, Jr.

— page 47 —
12
Serial 01775
CORE OF Fleet Post Office,
San Francisco, California.
27 November 1943.

THIRD ENCOUNTER TtC
CERO Report of
First War Patrol.

CONSURSPAC P.TTCI REPORT NO. 310
U.S.S. CERO - FIRST W.P. P.T.CL.

Subject: U.S.S. CERO (SS225) - Report of First War Patrol.
(26 September to 16 November 1943).

DISTRIBUTION:
(Complete Reports)
Cominch (5)
CNO (5)
Cincpec (6)
Intel. Cen. Fec.
Ocean Areas (1)
Comservpec (1)
(Adv.Base Plan,Unit
Cinclant (2)
Comsublent (6)
S/M School, NL (2)
Comscope (2)
Comsowespec (1)
Comsubsowespec (2)
CTF 72 (2)
CTF 16 (1)
Comsubspec (20)
SUB.D, NI (2)
Comsubspecsubordcom (3)
All Squadron end Div.
Commanders, Subspec (2)
Consubstrainpec (2)
All Subservices, Subspec(1).

NOTE: THIS REPORT WILL BE STORED IN THE
TO ENTERING P.T.CL. P.S.

J. A. WCOPRUFF, JR.,
Fleg Secretary.

— page 56 —
1.147(L): 3-10N : 1 atago : 36,000 : 200°t : Day surface
: 23 Dec.: 150-45B:Cruiser and: yds. : 20 : (hi.h per-
:

— page 59 —
5/22/45-3
U.S.S. CERRO (SS225)
Serial 01
Q-C-I-E-I-D-E-K-T-I-A-L

(K) :JOR DEFENSE AD DL-62 (CO TTD)

was noted to be discolored and this unit was pulled immediately. On disassembly, both halves of the crank pin bearing were observed to be burned up and the crank pin itself was scored. The adjacent unit to /4, namely /12, was pulled and showed no evidence of overheating; and /4 main bearings, located forward of these two units was pulled and appeared normal. It is the opinion of the Commanding Officer that this casualty was due to stoppage of tube oil to this unit possibly by a flake of bearing metal clogging the line from /4 main bearings to /4 unit crank pin bearing. Due to the necessity for grinding down the crank pin to fit oversize crankshaft bearings which are not carried on board, the ship's force was unable to put /4 main engine back in commission.

(2) :ain Engines - Xcessive smoke.
   -ain engines (inoton-24/8-a) exist so much smoke, particularly when making full power, as to constitute a grave military deficiency.
   -When crying to "end-around" a destroyer it was necessary to open the range before working ahead to avoid probable disclosure of our position by the smoke. This caused a loss of 10° in bearing in one case and contributed to the loss of opportunity to attack.)

(3) Slow Diving Time -
   This ship dives more slowly than others the officers on board have had experience with. There is an unusually long period at the "hesitation point", (at about 28 feet for approximately 10-15 seconds), particularly on a dive begun with /3 and /5 F.E.T.s dry and being used as normal ballast tanks. Two remedies are suggested which tend to eliminate air pockets:
   (1) Cut numerous holes in superstructure similar to GATO.
   (2) Cut vent holes in overhead of "dog house".

(L) RADIO
   Reception on low frequency was very bad except for about three hours each afternoon. At other times it was impossible to copy bells on low frequency.

-10-

— page 62 —
35 days
: 30 days

SS225/AL6-3
U.S.S. CERO (SS225)
Serial 01

G-C-E-E-I-E-E-E-T-I-A-L

(T) PROTOCOL OF INQUIRIES REGULATING:
    (T) 35 days
    (T) 30 days

It is the responsibility of aircraft search frequency by submarines to be delivered to the following frequency shall be maintained at all times when working in the same area as search planes. The submarine is to have from 35 to 45 days of reserve time on the time and the time

— page 63 —
0298
FF12-15(72)/A16-3/Pk
Serial 013
CONFIDENTIAL
Subject: U.S.S. CERO (SS225), Report of Second War Patrol - comments on.

serves a useful purpose but this was not one of them. With reference to the remarks on pages 11 and 13 about reception of contact reports, it has always been the practice of this command to install additional high frequency receiver for this purpose and CERO will be so equipped for next patrol. Referring to the Commanding Officer's remarks on page 12 regarding density layers, recent experience in the area north of Bismarck's has confirmed expectancy that density layers drop below three hundred feet at this time of year.

5. This is not designated as a successful patrol for purposes of award of the Submarine Combat Insignia.

6. The CERO will be given normal refit by the FULTON, estimated readiness for sea 3 February 1944.

DISTRIBUTION:
ComInch (Advance copy - 2)
VONO
VONAV (Op-23c)
Com 1st Flt
Com 2nd Flt
Com 3rd Flt
Comsubs 1st Flt
Comsubs 2nd Flt
Comsubs 7th Flt
CSG 6, 8, 10, 16, 18
CSD 81, 82, 181
OInC, S/M School, N.L. Conn. (2)
CTF 72 War Patrol Summary
Flt Radio Unit, MELBOURNE
All SS TF-72 (May be taken to sea, but BURN prior passing 50 South)
CO CERO (File)

— page 64 —
FF12-15(72)/A16-3/Pk
Serial 013
CONFIDENTIAL
2nd ENDORSEMENT to
CO CERO Report of
Second War Patrol
From: The Commander Task Force SEVENTY-TWO.
To: The Commander in Chief, UNITED STATES FLEET.
Via: The Commander, SEVENTH FLEET.
Subject: U.S.S. CERO (SS225), Report of Second War Patrol - comments on.

1. CERO sailed from MIDWAY for her Second War Patrol 13 December 1943. Passed to operational control Commander Task Force SEVENTY-TWO 66666 Z., 21 December near 7°-35' N., 155°-01' E. Ordered to patrol TRUK-KAVIENG-MUSSAU routes between latitudes 20 - 40 North. At 1147 L., 23rd sighted one heavy cruiser (tentatively identified as ATAGO class) with one unidentified ship on southerly course at high speed near 03°-10' N., 150°-45' E. CERO immediately went ahead full power chasing on the surface but had no opportunity to reach attack station. Tried all night to contact reports. Lost sight of enemy at 154L. Following day sighted northbound destroyer at 1652 L., but again was unable to reach position ahead for attack due to high speed of target. Lost target at dusk. 25 December - 2 January 1944, uneventful patrol in sea area except for numerous enemy plane contacts. Low in fuel, ordered TULAGI for refueling, arrived 8 January. Remained TULAGI 9th, proceeding with installation ABK equipment preparatory to returning to patrol area. 10th ordered to MINE BAY for regular refit in order to provide better distribution schedule of patrol and overhaul of submarines this Task Force. Arrived MINE BAY 12 January 1944. Thirty days on patrol, 11 days in area. No torpedoes fired.

2. CERO had only two contacts neither of which could be developed into attacks because of high speed of targets. Area coverage was good.

3. The Task Force Commander has long been convinced that use of the 3D radar in patrol area is readily detected by the enemy and traffic diverted away from our submarines whenever it is used, even intermittently.

4. There is no doubt that on 21 December CERO passed sufficiently close to OKOLUK to be detected by the enemy while on the surface. There are times when this

— page 65 —
15/18/A16-3/Pk
Serial 035
CONFIDENTIAL
1st ENDORSEMENT to
SECOND War Patrol
of the U.S.S. CERO
From: The Commander Submarine Squadron EIGHTEEN.
To: The Commander in Chief, UNITED STATES FLEET,
Via: The Commander Task Force SEVENTY-TWO,
The Commander, SEVENTH FLEET.

Subject: U.S.S. CERO (SS225) - SECOND WAR PATROL.

1. The second war patrol of the U.S.S. CERO, the first for the present commanding officer, was of only thirty (30) days duration, of which eleven (11) days were spent in assigned area. The CERO was recalled from patrol early for refit for operational reasons.

2. Two contacts were made with high speed targets which could not be closed for attack. No attacks were made and no damage was inflicted upon the enemy.

3. A normal refit will be given the CERO by the FULTON and Submarine Division EIGHTY-TWO relief crew.

G.H. WAILES,
By direction.

— page 67 —
1-1-1
From: Commanding Officer, U.S.S. CERO.
To: Commander in Chief, United States Fleet.
Via: (1) Commander Submarine Division ONE
          (2) Commander Submarine Squadron EIGHTEEN.
          (3) Commander Task Force SWEETY TWO.

Subject: U.S.S. CERO, Report of War Patrol Number 3.

Enclosure: (1) Subject report.
         (2) Track Ch. rt for Commander Task Force
         SWEETY TWO.

1. Enclosure (1), covering track number 3rd war patrol of this vessel, conducted on the Truk-Iew Ireland track between Latitude 25° and 50° N., on the Kavieng Palau track and on Hollandia - Palau track during the period 4 February 1944 to 27 February 1944, is forwarded herewith.

DECLASSIFIED-ART. 0445, OPNAVINST 5510.10
BY: 02-0218C-DATE: 3/2/42

DECLASSIFIED

— page 72 —
SS225/A16-3, U.S.S. CER0 (SS225)
Serial 05
C-O-N-Z-I-D-E-N-T-I-A-L-
Date: 10 Feb. 1715
Time: 1720
Came up and looked when astern of right flanker. Verified last impression that targets were less than 1000 tons. Executive officer confirmed by personal observation.
1720 Started for 300 ft. when one SC came around and headed for us. Noted that port screen (traveler) was crossing over to our side ahead of his charge, and flying a two pennant hoist. They night have seen our periscope because it was up quite long and probably had a very astonished expression on its objective lens.
1722 Idged for depth charge and put SC astern. He started to work astern of us but apparently never was sure of contact, although sound conditions seemed excellent and there was no gradient down to 350 ft. He hunted until about 1800 when he apparently went back and rejoined formation.
1618 Periscope depth. Formation still in sight. Heavy smoke, course 350°t.
1639 Surfaced; sent 2nd report.
1907 Upon completion transission headed for convoy with intention of drawing off escorts by gunfire if ZUC got in an attack.
1915 Sighted ZUC on surface bearing 319°t, exchanged recognition signals and closed for pow-wow. ZUC confirmed our opinion of targets as being too small. Considered going in for gun action, but deferred as unwise after considering ZUC's 3-inch gun, having noted a j-inch on trawler, and possible on one of the cargo vessels. Also figured five to two ration not advantageous, with more important work to be done at a later date.
1947 Turned south and continued patrol; having spent 29 hours, and much energy on five puny spit-kits.

— page 73 —
10 Feb. 2058
Date: 10 Feb. 2058
Time: 10 Feb. 2058
Transmitted: Transmitted amplifying report.
Transmitted: Transmitted

— page 76 —
15 Feb. 1515
Date: 15 Feb. 1515
Time: 1515
Sighted smoke with high periscope, bearing 2160t, distance 20 miles. Launched trawling stations. Sent to 4 engines.
Lost contact in rain squalls. Commenced closing on last true bearings. Tracking conditions very bad due to numerous rain squalls in vicinity of target, with CDR on an area of unlimited visibility. From here on it was a game of hide and seek. Radar picked up pip in middle of heavy rain squall, range 19,500 yds, 270°t.
Target suddenly became faintly visible through rain squall. High lookout could see 14m masts, top of stack, and upper bridge. Full visible from bridge. Also sighted one escort, probably large PC type. Devoted course and opened out as fast as possible. Target commenced smoking heavily, but gave no indication of turning away. At this time suspected we had been sighted. We should have been, except for the grey paint, small silhouette, and lousy Jap eyesight), but later events ended to disprove this. It later developed that the target smoked heavily incipiently, quite regularly. Target identified as similar to JN-3A-1, 85, ONI 20-7.
Lost target in heavy rain squall.
Commanded working around.
Target sighted 2320t. Opened out.
Target bearing 1690t. Daring closing in.
Radar contact 16000 yards, 153°t.
Red light, or more probably a red rocket, was exhibited from direction of target. The night was very black. . . .conrise at 0040.
Gave to base course and slowed to 2 engines at 2/3 speed.
Target out of radar range; last range 19000 yards. Slowed to 5 knots. Set sound water. Nothing heard.
Reversed course.

-8-

— page 77 —
15 Feb. 2108
Date: 16 Feb. 2117
Time: 0041
Sound heard pinging in direction of target.
Regained radar contact. Reversed course.
Hear'd eight distant depth charges. Target is obviously nervous. Continued tracking awaiting, moonrise. Determined zig-zag plan.

17 Feb. 0041
Sound heard pinging in direction of target.
Submerged to radar depth. Target just a blur in periscope. No escorts in sight, but heard pinging from two sources. Took position dead ahead of zig plane, plan-as target on left leg of zig plane, planning to swing right as soon as target zigged to his right and fire on that leg, thus putting his port escort well on his quarter, and his starboard escort well on the other side of him. Sound conditions appeared to be good.

0103 Target held left leg much longer than expected, so scanned swinging left to open track for stern shot. Port escort pinging too close for comfort, on port quarter.

0105 Target zigged to his right. Assumed target turned to base course, but radar pilot later showed him to be on course 340°C. After two more radar ranges, taken simultaneously with periscope bearings, went to 60 feet, because of the port escort being close on the port beam. Decided to fire escort generated torpedo run of 360 yards, (actual run 4000 due to under estimation of zig) because clouds threatened to obscure the moon and without the moon visibility by periscope was zero.

0113 Fired four torpedoes from stern tubes. As last torpedo fired, the moon went under and target became obscured. One escort pinging on 260°C relative, very close, but could not see him. The background in his direction was absolutely black.

0115 Diag'd for depth charge and started deep. Lat. 0-53°F, long. 146-20.

-9-

— page 79 —
5S225/AL6-3 U.S.S. CER0 (SS225)
Serial 05
C-N-Z-I-J-Z-N-T-I-Z-I
Date Time
17 Feb.
tion wave, and sounded definitely like a torpedo explosion.
(c) The second explosion was of a lower order than the first or the third explosion which was definitely a depth charge. It is assumed that this was an explosion at the end of torpedo run. It could also have been an explosion in the target.
(d) Although nothing was sighted in the sun-posed attack area, it is impossible to be certain we were anywhere near the attack area on our return because the gyro compass was secured for over 3 hours, and the course during evasion and later on the surface were magnetic and therefor only approximate. A fix obtained twelve hours after the attack, and run back, indicated that the closest we came to the attack area during the morning search was 4 miles, assuming magnetic courses and distances run were correct.
(e) The attack was started by the C.C. who turned away from the track instead of toward, and did that at too great a range. This was the result of paying too much attention to the escorts, and not enough to the target.
(f) Blair damage to one ship, similar to JUNO-1, 2, 3, 4, 5, OI-206-7; gross tonnage 6,162,072.
1100 Secured search of area and commenced search of probable track.
1223 Move to a cold detection by unidentified plane at 10 miles. Delivered to be a 3-24, but no IFF.
1235 Surfaced. Continued search.
16 Feb. 1124 Sighted object. Later identified as sur- faced submarine (FNC), bearing 267°T, distance 10 miles.
11:16 Sighted s.o.k. o.a convoy. Commenced tracking. This way or may not be the same one attacked on the 17th. From appearance of masts and stac. it is the same general type.

-11- CLOSURE (A)

— page 80 —
15 Feb. 1704
: 1707
: 1720
: 1726
: 1733
: 1753
: 1923
: 2345
: 19 Feb. 0100

: 15 Feb. 1704
: 1707
: 172

— page 81 —
1917-1919
SS225/AI6-3
Serial 05
C-O-N-E-I-2-I-T-I-a-L
Date: 19 Feb.
Time: 0602
outfit attacked on 17th, but did not notice three escorts at that time. The escorts are very helpful in that one of them emits a long dash on his sound gear, which was later observed to indicate a zig. This was used to advantage in the next attack. Firing on 16.5 kcs. 0602 Surfaced and commenced and around. Lat. 2-44 N, Long. 140-34 J. This was a touch one due to numerous rain squalls, which gave the target plenty of coverage. The ship played this visibility for all it was worth. Base course for last 24 hours was 265ft, whereas the course to ALAU was 308ft. He apparently ran with any rain squall he could find moving in its general direction. Played his and seek, and pressed around and at maximum speed to attack prior to attack. 1917 Sighted PTO and informed him of intention to attack immediately. Had no time to discuss situation with him, and since he was south of the track apparently waiting to make a later attack and had had first crack at target the previous night, he headed full speed for position. 1927 Submerged on track, 26000 yards ahead. 2035-34 Fired six (6) torpedoes from bow tubes. Impendin darned, damaged firing range. 2037 Rigged for depth charge, and started deep, due to close proximity of escort on our port bow. Heard three low order explosions, unidentified, and one terrific explosion, with prolonged rumblings, etc. 2041 Received first of twelve depth charges. The charges dropped were quite heavy ones. Three escorts working on us, with one or two stopping intermittently. The counter attack was haphazard. A unusual tactics involved. 2315 Surfaced. Announced clearing area to north (magnetic). Xcorts last heard south.

— page 84 —
22 Feb. 20 Feb.

SS225/A16-3 U.S.S. CER0 (SS225)

Serial 05

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

Date Time
20 Feb.

(a) This was a large vessel bound 53 from P.L.U. and which diverted course K2 as a result of our attack in that locality.
(b) This was a G.U.I. bound ship from
    ---CK ARI.
(c) This was a vessel attempting a dusk rendezvous with our convoy, either as additional protection for itself or the convoy, the convoy susposting (and rightfully so) that it was being tracked by at least one submarine for at least 30 hours. In any event, we admit not pressing this contact very vi-crously, having been in enemy contact almost continuously for four (4) days. No contact report was sent due to lack of concrete information later when it was considered safe to transmit.

0717
0825
21 Feb. 0715
Dawn dive. Proceeded south in accordance with 72 orders crossing P.L.U.-I.I.G. route.
Dawn dive. Decided on submerged patrol in P.L.U. route due to moxility to
HOLIDAY, equip visiing to enter area
unattested.
0922
0922
Sighted smoke bearing 150ft. Commenced closing, high speed submerged.
0931
0931
Sound picked up plinging.
1030
1030
Convoy consists of two large merchantmen, two small subchasers and one strange operating vessel, about 2000 tons, acting as port screen.
1110
1110
Leading ship appeared smaller or the two, and was obviously light. Decided to attack second ship.
1111
1111
Fired six torpedoes at second ship, similar to G.T.O.L.U., pg. 99, 011-206-J.
Gross ton. 68,001.
1133
1133
Nigged for depth charge. Starboard screen on port beat, about 1000 yards.
1135
1135
Started deep. Hear had heavy explosion, torpedo hit. Corresponding to 4100 yard run. (2 min., 45 sec.).

-15- ENCLOSURE (A)

— page 85 —
SS225/16-3  U.S.S. CENO (SS225)
Serial 05

Date: 21 Feb. 1136
Time: 11:36
Second explosion, lower order.
First of a series of light depth charges.
Heard nine successive metallic "cilinks" similar to shells exploding on water.
Seven more of same in succession.
Three "

— page 86 —
5/22/45 - U.S.S. CER0 (SS225)
Serial 05
C-C-N-F-I-D-E-N-T-I-A-L
Date: 21 Feb.
Time: 1940
Subclass type, was patrolling from beam to beam across the stern, making wide swings and pinging. At this point we found ourselves on the targets port quarter about 10,000 yards. Headed in, converging to draw ahead of limit of stern escort search. It is possible that our presence was suspected, because the stern patrol prolonged his search in our direction once, and pinged on us continuously for about eight pings

— page 87 —
22 Feb. 0430
Date: 22 Feb. 0430
Time: 0430
With target still afloat, and noonrise at 0550, decided to run in on surface and finish him off.
Fired four iron bow tubes, low over, at 6,000 yards, with perfect radar ranges and TBT bearings on stopped target. Depths set 6, 8, 10 and 12 feet, hoping to pick off an escort that lay between us and target. All missed. Do not understand this. Cleared area on four (4) engines.
Heard four (4) heavy explosions, but saw nothing. Time too great for torpedoes, so assumed they were depth charges.
Sd radar out of commission.
Sd radar in commission.
Down dive.
Sd radar.
Resumed search for target.
Sighted numerous logs and some lumber during forenoon.
Found target - still afloat, down by stern, listing to starboard badly, being towed. Just as suspected, she had additional assistance. Sent contact report, opening out of sight contact during transmission. Never rescinded contact, but searched until 2300. In very heavy rain squalls, visibility 0-500 yards, from about 2030 until 2300. The Nips, if still afloat, were in a rain squall as usual.
Sent negative information to Balao and retired enroute LAMYEAR BAY in compliance with CTF 72's orders.
| Date | Time |
|------|------|
| 22 Feb. | 0430 |
| 23 Feb. | 0445 |
| 24 Feb. | 0455 |
| 25 Feb. | 0465 |
| 26 Feb. | 0500 |

1510 Lyriq to in Lungenak day in vicinity U.S.S. VOLU. Rocked no fuel.

— page 88 —
15-19
SS225/A16-3
U.S.S. CHRO (SS225)
Serial 05
C-O-N-E-I-D-E-N-T-I-L
Date: Feb. 26
Time: 1546
Feb. 27: 1400
Feb. 28: 1840

(C) HEATHER. (2-4 N, 147-150 E).
Frequent heavy rain squalls encountered causing
difficulty in keeping enemy convoy in sight. Seas calm.

(D) TIDAL INFORMATION.
None.

(E) NAVIGATION. AT SEA.
1. The Jeger Harbor, New Guinea, blueprint chart
is apparently quite accurate. The cuts on island tangents
gave "pinpoint" fixes.
2. In area 2-4 N, 147-150 E set and drift as follows:
Average over period 9-16 Feb. 1944
300°T, 0.9 knots.

-19-

— page 89 —
1. 10 : 0-06N : 20,000 : 350° : 00D
: 2. 16 : 0-10N : 6000 ton : 7 : 35,000 : 305° : Lookout
: 3. 16 : 2-4JN : 6000 ton : 35,000 : 265° : 7 : 35,000 : Lookout
: 4. 21 : 0-18S : 1-8600 : 25,000 : 320° : 7 : 25,000 : 320° :

— page 91 —
1. Haru similar to Johore Jaru with 2 P.C. escorts. Si it contact - Smoke. Daylight; visibility - passing squalls.
Ships Sunk: Non certain.

Chips Damaged or 1 hit in ship similar to Johore probably sunk: |, 2, 85 OTI 208-J; gross tonnage 0.162-0.072.

Damaged  |  Record torpedo hit at time for 4000 yd. run.
determined  |  Target screws stow ed, never heard by:
  |  (Do not think target would stand on alone).

Target Draft 30(ost.)  |  Course 340  |  Speed 8
Range 3600 yds (at firing).

Own Ship Data
Speed 3  |  Course 240  |  Depth 60 ft.  |  Track 100 port (at firing).

Fire Control and Torpedo Data
Type Attack: |

— page 92 —
7 : 5 : 9 : 10 :
Track angle : 100 : 100 : 100 : 100
Gyro angle : 202 : 201 : 199 : 199
Depth Set : 6 : 6 : 12 : 12
Power : Hi : Hi : Hi : Hi
Hit or Miss : -Miss : -Miss : -Hit : -Miss
Arratic : No : No : No : No
Mark Torpedo : 14-3A : 14-3A : 14-3A : 14-3A
Serial : 20318 : 39767 : 39233 : 39189
Mark Exploder : 6-4 : 6-4 : 6-4 : 6-4
Serial : 9512 : 7246 : 12281 : 12316
Actuation Set : Contact : Contact : Contact : Contact
Actuation Actual : --

— page 94 —
1 : 2 : 3 : 4 : 5 : 6
Angle: 50 : 50 : 50 : 50 : 50 : 50
Gyro angle: 004 : 005 : 007 : 005 : 004 : 005
Depth set: 6 : 6 : 6 : 12 : 12 : 12
Power : Hi : Hi : Hi : Hi : Hi : Hi
List : : : : : : : : :
List :

— page 96 —
1 : 2 : 3 : 4 : 5 : 6
Fired
Tracks
Angle
Gyro angle
Depth set
Power
Hit or
Miss
Aircraft
Torpedo
Serial
Lark
Exploder
Actuation
Set
Actuation
actual:
Lk. War
Head
Serial
Explosive
Piring
Interval
Type spread
Sea
Conditions
Overhaul
Activity

: 70

— page 97 —
SS225/416-3    U.S.S. CHRO (SS225)
Serial 05
C-Q-N-F-I-D-E-N-T-I-A-L-
U.S.S. CHRO    TORPEDO ATTACK NO. 4, PATROL NO. 3
Time: 19-36-08    Date: 21 Feb. 1944    Lat. 0-27 S.
Long. 139-35

Target Data - Damage Inflated
Description: Similar to Ginyo Maru Class.
Already Stopped by one hit our attack No. 3, 2 escorts.
Ship Damaged: One Ginyo Maru Class, 8600 tons.
Damage
Determined
By: Heard one hit.

Target draft 25    Course Stopped Speed 0
Range 8000 (at firing). (Estimated 6000 at time of firing).

Cwn Ship Data
Speed 3    Course 0    Depth 63 feet.
Track angle 50

Fire Control and Torpedo Data
Type Attack: Day periscope. Straight shots, low speed, longitudinal spread.

-28-    ENCLOSURE (A)

— page 98 —
7 : 6 : 10 :
Tubes Fired : 50 : 50 : 50
Truck Angle : 160 : 180 : 180
Gyro Angle : 6 : 6 : 12
Depth Set : Lo : Lo : Lo
Hor or Miss : .iss : .iss : .lit :
Erratic : ko : No : No
.ark Torpedo : 14-3a : 14-3a : 14-3A
Serial : 22919 : 22256 : 24680
.ark Exploder : 6-4 : 6-4 : 6-4
Serial : 7238 : 7271 : 1355
Actuation Set : Contact : Contact : Contact
Actuation
Actual : -- : -- : Contact

— page 99 —
5/22/45 U.S.S. CERO (SS225)
Serial 05
Q-C-I-P-I-D-E-N-T-I-L-L
U.S.S. CERO TOPPED ATL-OK NO. 5 PATROL NO. 3.
Time: 05-09-12 Date 22 Feb. 1944 Lat. 0-36 S.
Long. 139-31 E.
Target Data - Dense Inflated
Description: Ginyo Naru Class plus 2 escorts.
Ship: None. Torpedoes missed above ship which
Damaged: was stopped by 2 previous torpedo hits.
Target draft 25 Course Stopped Speed 0
Range 6000 yds (at firing)
Own Ship Data
Speed 9 kts. Course 257 Depth Surface
Angle 50 m.
Fire Control and Torpedo Data
Type attack: Night surface low power shots. Set up
TDC for target speed zero, put in IBT
bearings, set in spread by offset,
radar ranges.

-30- CLOSURE (A)

— page 100 —
4 : 3 : 2 : 1
Track angle : 70 : 70 : 70 : 70
Gyro angle : 358 : 358 : 359 : 350
Depth set : 12 : 10 : 8 : 6
Power : Lo : Lo : Lo : Lo
Nit or aliss : Miss : Miss : Miss : Miss
Erratic : lo : no : lo : Yes
Hark Torpado : 14-3a : 14-3a : 14-3a : 14-3a
Serial : 22280 : 25263 : 25235 : 22348
Hark Exploder : 6-4 : 6-4 : 6-4 : 6-4
Serial : 12616 : 12004 : 12111 : 12620
Actuation Set : Contact: Contact: Contact: Contact
Actuation
Actual : -- : -- : -- : --
1k. per head : 16 : 16 : 16 : 16
Serial : 10432 : 10441 : 10098 : 5688
Explosive : TPX : TPX : TPX : TPX
Firing
Interval : 00 : 08 : 14 : 20
Type Spread : Divergent: Divergent
Sec Conditions : Calm : Calm : Calm : Calm
Overall
Activity : U.S.S. FULION U.S.S. FULION

-31- ENCLOSURE (A)

— page 107 —
15/8/A16-3
Serial: 020
C-O-N-F-I-D-E-N-T-I-A-L
FIRST ENDORSEMENT to
CO, USS CERO Report
of 3rd War Patrol.

From: The Commander Submarine Squadron EIGHTEEN.
To: The Commander Task Force SEVENTY-TWO.

Subject: U.S.S. CERO (SS225) - Third War Patrol - Comments on.

1. The third war patrol of CERO, conducted in the area north of the BISMARCKS and NEW GUINEA, was of only 23 days duration, 15 of which were spent in the area.

2. Four enemy ship contacts and five attacks were made. One contact was with small ships considered unworthy of torpedoes. The other three contacts were aggressively attacked.

Attack #1 This was a night attack conducted at radar depth. Four torpedoes were fired at an excessive firing range and one timed explosion heard gave evidence of one hit. Depth charge attacks prevented the enemy from developing a favorable and the 10° divergent spread employed covered about 150% of target length. The excessive torpedo run was caused by turning away from target's track followed by a zig away by the target.

Attack #2 This was a submerged attack at periscope depth, in evening twilight. Two timed hits were heard but again the firing range was excessive although small gyro angles were used with a fairly sharp track. The 5° divergent spread employed with the six torpedoes fired covered about 175% of targets length. Subsequent depth charge attack prevented observation of damage but PETO later reported target had sunk.

Attack #3 This was a daylight submerged attack at periscope depth. Six torpedoes were fired and one timed hit was heard. Firing range again was excessive but gyro angles and track angles were favorable. The 10° divergent spread covered over 200% of target length. Later observation of target, after depth charge attack, showed target stopped with stern low in water.

— page 108 —
0-0-N-F-I-D-E-N-T-I-A-L
Subject: U.S.S. CERRO (SS225) - Third War Patrol - Comments on:

---

**Attack #4**
This was a submerged long range attack at periscope depth on same target at attack No. 3. Three torpedoes were fired in low power from 6,000 yards because of activity of escorts One timed hit was heard. Small gyro angles were fired on a fairly good track angle; the longitudinal spread covered 150% of target length. After the usual depth charge attack, target was again sighted stopped.

---

**Attack #5**
Another long range attack on same target as attack No 4, night surface, firing four torpedoes in low power from 6,000 yards. No hits were obtained probably because target was drifting and spread employed covered only 50% of targets length. Small gyro angles and a favorable crack angle were used.

---

3. In general, all attacks were well conducted with the exception of the tendency to shoot at an excessive firing range. This was partly caused by activity of escorts. There exists some doubt as to whether the target attacked in attacks No.1 and No.2 was the same target or two difference targets. A study of the positions of the two attacks and the relative times and distances involved tends to strengthen the belief that there were two different targets, since the damaged target of attack No.1 would have to have made good a speed of over seven knots to be in the position of the target attacked in attack No. 2.

---

4. It is recommended that CERRO be credited with the following damage inflicted that enemy:
   - **SUNK**
     - 1 AK (JAHORE MARU class) - 6,132 tons
   - **DAMAGED**
     - 1 AK (JAHORE MARU class) - 6,182 tons
     - 1 AK (CINYO MARU class) - 8,600 tons

---

5. CERRO returned from patrol in very good material condition. Three weeks' refit will be given by Submarine Repair Unit in order to accomplish installation of new type trinump.

---

6. The Squadron Commander congratulates the officers and crew of CERRO on this successful patrol and on inflicting serious damage to the enemy.
(Authentification of next page)

— page 110 —
1. The Commander Task Force SEVENTY-TWO, To: The Commander-in-Chief, UNITED STATES FLEET. Via: The Commander, SEVENTH FLEET.

Subject: U.S.S. CARO (SS225) - Third War Patrol - Comments on.

1. CARO departed LINES BAY, 4 February 1944 for her Third War Patrol. Arrogate DRECHT HARBOR, NEW GUINEA conducted two days training with COUCAL. Topped off fuel 6th from COUCAL in DRECHT HARBOR and proceeded on to patrol area via VITIA STRAIT to cover TRU-NE/HANOVER-KAVALEN convoy routes bet.een 2-20 Oct 1943. First contact 10th, two small marnu northbound with three escorts. After making two approaches decided not worthwhile torpedo targets. 12 February ordered to patrol PALAU-RAJAU convoy routes. Second contact 16th one medium marnu with two escorts on northwesterly course. Made night radar submerged attack, at 0113L, 17th firing four torpedoes near 0-53 N, 14-26 E. Forced deep immediately to evade counter-attack by escorts, heard one timed hit. After ineffective depth charge attack, surfaced and gave chase. Later in afternoon 15th, sighted PSTO and set up search plan. 16th 18th-19th, made radar contact single marnu similar to this previously attacked with three escorts near 02-43 N, 14-74 E. A submerged radar detected below unknown successful, surfaced and made and around. At 1927L, 19th, fired six torpedoes. Heard two hits. Escorts delivered depth charge attack, no damage. CARO was unable to witness result of PSTO nearby saw target sink near 03-22 N, 13-28 E. 20 Feb. 20 torpedo patrol PALAU-HOLLANDIA traffic lanes. Enroute near 0-18 S, 139-42 E, cut-tected northbound convoy two frei.hors, three escorts. At 1131L fired six torpedoes at larger marnu, 8600 ton freighter. Heard one hit. Surfaced at 1425L following depth charge attack, target stopped but still afloat. After submerged approach to 8000 yards fired three torpedoes set in low power. One hit. Escorts dropped depth charges, none close. Surfaced at 23AL, in aelatively regained contact with target. Made surface attack before dawn 22nd firing four torpedoes again set in low power, range 6000 yards, all missed. All torpedoes expended except one defective through flooding, forced to lie very hard by damaged but still afloat, being towed toward HOLLANDIA. Roalled to base and arrived after uneventful trip via VITIA STRAIT 27 February. Twenty-three (23) days on patrol, fifteen (15) days in area. Fired twenty-three (23) torpedoes, five (5) hits.

2. This is considered a successful patrol for purpose of award of the Submarine Combat Insignia.

3. CARO is in excellent materiel condition. Normal refit including overhaul four main engines and docking will be accomplished by Sub.rine Repair Unit, BRISBANE. Estimated date readiness for sea 27 March 1944.

— page 111 —
0729
Serial 088
C-C-N-P-I-D-E-N-T-I-A-L
Subject: U.S.S. C-RO (SS225) - Third air Patrol - Comments on.
4. The commanding officer, officers and crew of CRO are congratulated for inflicting the following damage on the enemy during Third air Patrol:
SUNK
1. Frig. corr, Medium 6100 tons
DAMAGED
1. Frig. corr, Large 8600 tons
JAMES FISH
DISTRIBUTION:
Consuls (Advance copies - 3)
VONO (Advance copies - 2)
VOPM-V (0-23c)
COK. 1st Ftl.
COK. 2nd Ftl.
CO. 3rd Ftl.
Consuls 1st Ftl.
Consuls 2nd Ftl.
Consuls 7th Ftl.
CSS-4, 6, 8, 10, 12, 14, 16, 18 and 20.
CSD-181 and 182.
CTF-72 War Patrol Summary.
Oino, S/M School, N/L Corr. (2).
Flt. radio Unit, Melbourne.
All SS TF-72 (May be taken to sea, but BURN prior to passing 5° South).
CO USS CRO (File).
M. S. PAGE,
Flag Secretary.

— page 112 —
29 MAR 1944

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

THIRD ENDORSEMENT to
CO USS CERo conf. 1tr.
SS225/Al-3, serial 05
of 27 February 1944.

From: The Commander SEVENTH FLEET.
To: The Commander in Chief, UNITED STATES FLEET.

Subject: U.S.S. CERo, Report of THIRD War Patrol.

1. Forwarded.

H. W. GRAF.
Chief of Staff.

— page 113 —
3 Fleet Post Office,
San Francisco, Cal.

Serial 03
2 June 1944.

From: Commanding Officer, U.S.S. CERO.
To: Commander in Chief, United States Fleet.
Via: (1) Commander Submarines Division OIC
    (2) Commander Submarine Squadron EIGHTEEN.
    (3) Commander Task Force SEVENTY TWO.

Subject: U.S.S. CERO, report of War Patrol
Number 4.

Enclosure: (A) Subject report.
(B) Track Chart for Commander Task Force SEVENTY TWO.
(C) Plots of torpedo attacks for Task Force SEVENTY TWO.

1. Enclosure (A), covering t: 3 4th war patrol of this vessel conducted in the Panama area bet een la itue 00 to 80T. and longitude 127° to 130°. during the period april 3 to June 2, 1544, is forwarded herewith.

S. F. DICHTEN.

DECLASSIFIED--ART. 0445, OPNAVINST 5510.1C
BY OP---03891C DATE 5/31/42

— page 122 —
25 Apr. 0631
: 1730
: 2012
: 30 Apr. 0628
: 2016
: 2221

: 25 Apr. 0631
: 1730
: 2012
: 30 Apr. 0628
: 2016

— page 126 —
0825/A16-3 U.S.S. CERRO (SS225)
Serial 08
C-O-N-F-I-D-E-N-T-I-A-L
Date: 4 May 0840
Time: 0840
Sixty-foot type plate, about 300 feet, rigged for depth charge. Thought he had seen us, but nothi s happened.
0850
Periscope depth charge. Continued. Scoured from depth charge. Continued periscope patrol on course normal to destroyer's track, hoping to find his convoy. Nothing sighted.
1025
Surfaced. Came to estimated course of DD, 225°, went unsued 4 engine. Speed, to overtake and search for convoy.
1034
Sighted Jap fleet plane astern. Submerged. Decided detection by aircraft was eminent if not ready a fact, therefore making it useless to pursue the destroyer. Decided to continue periscope patrol across east-southeast track. Suspected DD and aircraft might be well in advance of convoy conditions, sub hunt. When nothing soon or heard, at
1247
surfaced. With insufficient fuel to get around DD, and considering it possible that convoy was still coming through the area decided to conduct surface search on two generators or cross-crossing on reverse of estimated convoy course.
2015
With no contact dusk abandoned search and headed for Seadlor running 2 engines during daylight and 1 engine at night.
Loon posit - Lat. 06-32N
Long. 125-09E
Fue1 used - 3409
Liles steamed - 256.8
1208
Submerged, aircraft at 12 miles.
1308
Surfaced. Our route passed close to the Sansorol Is. and in view of activity there reported by BLUEBILL, decided to close the islands and look for possible targets. Low visibility might permit our getting close enough on the surface to permit diving and closing the island submerged.

-13- ENCLOSURE (A)

— page 133 —
22 May 0623
Date: 21 May
Time: 0200
Date: 23 May 0200
Date: 0540
Date: 0600
Date: 0649

U.S.S. CSRO (SS225)
Serial 08
C-O-K-F-I-D-E-N-T-I-A-L
Noon posit - Lat. 00-20N
Fuel used - 820
Miles steamed - 152.5
Dawn dive. Periscope patrol off
Pt. Lelai.
Surfaced. Heeded for [ROTATI]
channel.
Received orders concerning de-
par ture from area.
[ROTATI]
Long.129-30E
Fuel used - 206.2
Miles steamed - 206.2
Approaching. [ROTATI] Straits from
northwest, to take station to
intercept convoy reported by
BLU XGILL. Seas calm, visibility
good, quite dark.
Radar contact, 4000 yards, 000°t,
not sighted. From range at which
detected and size of rip decided
contact was a patrol boat about
FU size. He was headed northerly
at about 10 kts. Put him astern,
and worked around in toward station.
Stopped and scanned sound gear.
Nothing heard.
Radar contact, 10,000 yards, 225°t.
This was a larger target than
previous contact, and was apparently
proceeding in a northerly direction
from [ROTATI] Straits. Impending dawn
prevented tracking so at 0620 dove
to [ROTATI] periscope depth to await de-
velopments.
Sound reported pinging from 335°t,
but no pinging or screws from our
southerly contact. Made out
southerly contact to be a large
patrol vessel, similar to U.S.S.

— page 134 —
23 May
SS225/A16-3
Serial 08
G-O-N-F-I-D-E-N-T-I-A-L
Date Time
23 May
GRASSHUT, searching in a "sine curve"
sweep in a northerly direction, about
8000 yards range. Turned away from
him and toward pinings, and immediately
slipped smoke off at least four
ships, bearing 335°, hull down.
Estimated range 20,000 yards.
attached to use wake of the channel
sweeper to conceal our presence, by
getting astern of and slightly to the
south of him, this putting him between us and the convoy.
0723
Digged for silent running and changed
course to put channel searcher ahead.
Did not like prospects of his towing
a lethal weapon, so Scythe's torpedo
ful distance astern of us.
crossed our bow to collide with
changed his base course to about the
normal approach course for the convoy,
and stealthily proceeded to escort us
to the target. This pleasant interlude
was short lived however, for as time
escorts of the convoy now into
signs, our escort drifted off to the
south, and we regretfully abandoned
him to work our way through the three
Chidorio class escorts who were
patrolling ahead and on each bow of
the convoy, pinging. The convoy
consisted of three and um (6000-
8000 tons, gross metric) formed in
a sloppy line abreast, estimated
range between columns 800 yards.
The center ship was ahead, the right
flank ship (away from us) was about
two points abeit bow, and the
near ship was broad on the center
ship's quarter. This presented a
beautiful overlapping target for
about a 120 track on the near ship,
so maneuvered for that position.
The near ship was flying a flag from
triatic stay consisting of horizontal

— page 135 —
0825
SS225/Ai6-3 U.S.S. CSRO (SS225)
Serial 08
C-O-N-F-I-D-E-N-T-I-A-L
Date Time
23 May
stripes, blue, white, blue. astern of the near ship was a smaller old type AK, possibly 2000-3000 tons, and beyond him periscopes there were other small vcssels, although by this time the overage had become so thick that prolonged periscope observations were not demanded. vis.ble, and no c.t.t.p.t was made to locate any other targets. a quick look at nod disclosed the presence of any tankers

— page 139 —
SS225/AL6-3
Serial 06
C-O-N-E-I-D-E-I-T-A-L
Date 26 May 0015
Time 00:15
Bridge watch (000, 100D, and Lookouts) heard blood curdling scream close aboard. Headed in direction of sound and had a radar pip on that bearing which disappeared at 1200
ds. (This happened twice). Saw nothing. (Tosit Lat. 1-57N; Long. 125-30E). This could have been a Jap on a raft.
Note: We have now been out 53 days and the OOD at the time of above incident has made 10 war patrols (this being his 6th. cons.cutive). He was slated for new construction prior to this patrol but shortage of watch officers necessitated taking him with us. Hope he makes the States this time in.
0635
Kalmaiert--Periscope patrol on spotty; bad surface patrol conditions.
2035
Surf-ood.
Noon posit - Lat. 03-17N
Long.129-47E
Fleet used - 2200
Diles steamed - 104.0
27 May 0200
Heard heavy rumbling so unds which sounded like aerial bombs being dropped, "robbbly on land, at a considerable distance.
0210
Stoppy end. [listened with JN, heard nothing.
0615
Down dive. Periscope patrol off Pt. Ft.ak (Last Coast Malahra). Sea glassy all day.
2018
Surf-ood.
Noon posit - Lat. 01-17N
Long.128-53E
Fleet used - 1595
Diles steamed - 1.7.3
28 May 0607
Dawn dive. Periscope patrol off Ake Lano Bay (Last Coast Malahra). Sea glassy.

-26-
CLOSURE (A)

— page 140 —
2023/016-3 U.S.S. CERRO (SS225)
Serial 08
C-O-N-F-I-D-E-N-T-I-A-L
Date Time
26 May 2023
Surfaced
Noon posit- Lat. 1-28N; Lon.128-53E
Fuel used - 1450
Files steamed- 130.3
29 May 0635 Dawn dive. Periscope patrol on Halmahera-Palu line. Cloud conditions bad for surface patrol.
1955 Surfaced. Headed for point Acid in safety lane.
2152 Sent posite for return to Seeadler.
2400 Entered safety lane, departed area, and headed for Seeadler.
Noon posit- Lat.02-42N; Long.129-55E.
Fuel used -2354
Files steamed- 165.3
30 May 0636 Cut in ABN for continuing operation.
Commenced operating. SD incrementally.
1111 Submerged, unidentified aircraft 20 miles.
1238 Surfaced.
Noon posit-Lat.03-12. Long.132-47E.
Fuel used - 270
Files steamed- 222
31 May 1025 Surfaced. Set watch on ARO for tonight.
2030 Sent watch on ARO for tonight.
Noon posit-Lat.01-00N; Long.137-50E.
Fuel used -4200
Files steamed - 336
1 June 1200 Fired 40mm gun for test purposes. Foot firing was sticky on the first 4 shots after which the gun fired satisfactorily.
Noon posit-Lat.00-378; Long.143-133.
Fuel used - 4200
Files steamed - 336
2 June 0200 Passed U.S.S. CREAM on opposite course.
0600 Made rendezvous with escort SC982 and proceeded to Seeadler Harbor.
1200 Arrived Seeadler Harbor and moored alongside U.S.S. JURAJ.
Noon posit- Seeadler Harbor.
Fuel used - 3500
Files steamed - 278

-27- ENCLOSURE (A)

— page 142 —
35225/A16-3
Serial 08
C-0-E-P-I-D-Z-E-N-A-L
(F) SUP CONTRACTS.

SS225/A16-3
Serial 08
C-0-E-P-I-D-Z-E-N-A-L
(F) SUP CONTRACTS.

NOTE:
P = Periscope  R = Radar
SK = Surface night
SD = Surface day  JK = Sound gear

Date & Time:
No.: 1944
Date: 1.02.1944
Time: 1:00
Date: 1:32-3:00
Time: 1:00
Date: 1:00
Time: 1:

— page 150 —
8.5" x 11" (22.9 x 27.9 cm)

SS225/A16-3

Seri: 08

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

U.S.S. CERO TORPEDO ATTACK NO. 1 PATROL IC. 4

Time: 0857K Date: May 21 1ct. 0-15N. Long. 12C-5E.

Description: Convoy: one medium near similar to Cheribon near page 111 OCT 2087 (revised), 2 trawler type escorts. Cont. was made by sighting smoke. Visibility was good. On hit. This vessel might have been some sort of a naval auxiliary as the personnel seen topside were white working uniform, and the ship had the general appearance topside of a naval vessel, and not merchantman. Most of the observations were taken very rapidly due to the danger of being sighted in the extremely clear sea and most of those were made with a small angle on the bow, so identification is not positive. At least one, and possibly a pair of ornas similar to but smaller than the type carried on the stern of U.S. cruisers of BROADY class were seen on the after island of this vessel.

Ship Damaged: One Cheribon iaru class, 4026-4076 tons.

Damage determined by - Hard on hit, slot showed tails to be 3rd torpedo.

Target draft 10.1 Course 148.5 Speed 6.3 kts.

Range 1600 yds (at firing).

Own Ship Data

Speed 3 Course 010 Depth 65

Fire Control and Torpedo Data

Type Attack: Day parisocope, small gyro angles, 110 trace angle, TDO used, divergent spread, fired 1 and 3 on pariscope bearings and 2 and 4 on generator bearings.

-37- ENCLOSURE (a)

— page 152 —
2025/AL6-3
Serial 06
C-O-N-F-I-D-E-K-P-I-A-L
(TIME: 0828A Date: May 23)
(H) ATTACK DATA
Lat. 2-38N; Long. 128-08E.
U.S.S. CERRO TORPEDO ATTACK NO. 2 PATROL NO. 4
Torpedo Data - Damage Inflicted

Description:
Convoy: three medium nems in line abreast;
port flanker sinker to Panama; maru page 173 ONI 2085 (rivisad) and center ship sinker to Okitu
Naru page 120 same publication; one small naru
castern of 3 leading ships about 2000-3000 tons;
about 3 smaller ships beyond this small naru; 3
Cidiori escorts grouped around big ships; FC
escort on port quarter convoy; carrier coverage consisting of 3 Betty's and 3 Devos. Contact was
made by sighting smoke (plunges was heard shortly
afterwards). Visibility was good. Four nits.

Ship sunk: One Panama Naru class, 5286 tons,
probably being used as transport.

Ship damaged or
Probably sunk: Orz Okitu Naru class, 6666 tons.

Damage determined by:
The plot definitely shows hits by A1 & 2
torpedoes, at a time corresponding to the run to
the north. The first torpedo was a 2nd torpedo
two hits in the center (overlapping and beyond the
first target) target, by torpedoes K. 4 and 6.
Torpedoes 33 and 5 were spaced aft, and apparently
missed in the direction. They were also heard
running after the four hits. In addition to the
unmistakable quality of deep torpedo hits, the
first two explosions were followed immediately
by the familiar "blowout" sound effect
associated with solid hits, and this in turn was
followed by the familiar smashing and cracking
sounds associated with a sinking ship which could
be heard intermittently (between depth charges)
for a period of about 20 minutes from the gun
eral direction of the targets. The second group
of two hits, while unmistakably torpedo hits, were
not followed by the "blowing" sound effect to
as great a degree as the first two, possibly due
to the range. The intensity of the smashing
and cracking sounds varied and it could not be
said truthfully that the volume was increased
any after the second group of hits. For this
reason damage only is claimed in the second target,
although there is a very good possibility that it
too sank.

-39- ENCLOSURE (A)

— page 154 —
1 : 2 : 3 : 4 : 5 : 6
: 105 : 105 : 110 : 110 : 110 : 110
: 355 : 353 : 350 : 345 : 340 : 340
: 12' : 12' : 12' : 12' : 12' : 12'
: 51 : 51 : 51 : 51 : 51 : 51
: 11t : 11t : 11t : 11t : 11t : 11t
: 10 : 10 : 10 : 10 : 10 : 10
: 14-3A : 14-3A : 14-3A : 14-3A : 14-3A : 14-3A
: 25742 : 24416 : 23075 : 25826 : 25892 : 25890
: 6-4 : 6-4 : 6-4 : 6-4 : 6-4 : 6-4
: 6015 : 697 : 9747 : 4076 : 2160 : 55
: Contact: Contact: Contact: Contact: Contact: Contact
: Contact: Contact: -- : Contact: -- : Contact
: 16 : 16 : 16 : 16 : 16 : 16
: 12472 : 3440 : 3441 : 3337 : 12541 : 3386
: TPX : TPX : TPX : TPX : TPX : TPX
: 00 : 07 : 20 : 30 : 37 : 45
: DIVERGENT : DIVERGENT : DIVERGENT : DIVERGENT : DIVERGENT
: 3/4"aft: 3/4"Fwd: 2"aft : 2"Fwd. : 3"aft. : 3"Fwd.
: 1710* : 1725* : -- : 2500* : -- : 2660*
: 1 : 1 : 1 : 1 : 1 : 1
: TORPEDO SHIP BRIGANT, AUST.

*Timed. Others generated.

-41- ENCLOSURE (A)

— page 158 —
55225/AL6-3
Serial 08
Q-Q-N-Z-I-D-Z-N-T-I-A-I
(K) MAJOR DIFFICTS AND DILIGENCE (CONT'D)
battery trip switch and excitation was lost. Naneuvering noted the after battery voltmeter drop off, threw all generators clear, sent a man into battery well to reengage the after battery breakers and propulsion was regained after a very short lapse of time. To prevent any further recurrence of this casualty a guard similar to the one over the fwd. battery trim switch has been installed which must be lifted clear before the switch can be tripped. Personnel have been thoroughly instructed as to the cause of this casualty.
(b) While instructing the junior electricians in the manipulation of the levers at the maneuvering room control stand, a dead generator was identified placed on the battery bus and the switch over the electrician was instantly aware of the result of his miscue and after throwing generator load clear, sent a man into the battery wells, reengaged the breakers, and propulsion was regained after a short lapse of time.
To prevent any further recurrence of this casualty, instruction for junior electricians will be carried out by means of circuit diagrams and simulated movements.
The generator was inspected thoroughly, tested on battery and propulsion and found undamaged.

(L) RADIO
Bellicomen:
Radio reception was usually very good on 8430 ke except during transmission of submarine numbers when Japanese interference prevented complete copying of messages, necessitating continual re-copying when possible. The interference consisted of dummy point to point traffic or indiscernate keying. On one occasion, lay 3, No. 965 was sent out as 629 by mistake and copied perfectly by our operator. Immediately after completing the message the number was corrected and the message repeated accompanied by immediate Japanese interference.

— page 160 —
5/23/44 - SD failed to operate. Trouble
trao.d to siorts in the high voltage loads in
receiver rectifier and transmitter filament
c014-4's. Tnase siorts were duo to moisture
collocated during eight hours of deep submergence
and depth charge attack.
SD-1:
(1) 4/11/44 - R-44 in FPT unit opened up - no
apparent reason - half hour out of commission.
(2) 4/27/44 - C-22A) Transmitter unit shorted.
(3) 5/6/44 - C-10) Difficult to locate.
2-3 probably due to overheating. Oil had leaked
out of condensers. Isolation network was changed.
The oil one had leaked some oil.
(4) 5/10/44 - Sensitivity had gradually w. gone.
Several I.F. tubes in the range indicator unit were
changed. The first I.F. seemed to have the great-
est offset on sensitivity. The crystal in this crystal
converter unit was also changed and the
choked. Results were very good.
On numerous occasions in the area false pips
were encountered on the SF which were very trouble-
some. These pips generally occurred at night and had
all the characteristics of positive contacts appar-
ing on all possible bearings at ranges of 500 to
4000 yards, the majority being around 2000 yards.
The weather during these encounters always consisted
of a flat calm sea, no wind and low lying mist or
haze extending to about 1000 ft elevation and making
visibility very difficult. The action of the true
bearing of those contacts would differ; remaining the
same, moving with the ship so as to give the same
relative bearing, or different headings, or moving
very rapidly.
It is suggested that those pips were echoes
obtained from layers of air of different density
resulting from different levels of air at different
temperatures. The minor lobes from the radar screen
which emanate at different angles above the horizon
would reflect from such a layer. The layers of
different density are caused by the cooling effect of
an upper area wind, after the sun goes down, while
the lower layer of air is heated by the warm water.

-47- ENCLOSURE (A)

— page 166 —
1. The Commander Submarine Division 182.
To: The Commander-in-Chief, U. S. Fleet.
Via: (1) The Commander Submarine Squadron EIGHTEEN.
(2) The Commander Task Force SEVENTY TWO.

Subject: U.S.S. CERO (SS225) Fourth War Patrol-Comments on.

1. During the fourth patrol of U.S.S. CERO, twelve surface contacts were made, of which only two presented opportunity for torpedo attacks. These two were both convoys and attacks were made in each case.

Attack #1 was made on 21 May 1944, on a vessel of a Cheribon Iaru class escortader by two trawler type escorts. This was a day periscope approach; four torpedoes were fired from inside the screen; range 1600 yards, mean gyro angle 15° right, mean track 100°; spread used in 150° left, range 1700 yards to target. This attack resulted in one timed hit. Under the prevailing sea conditions and in view of the fact that the target changed course during firing and that it was protected by two close screening vessels, this is considered a good attack.

Attack #2 was made on 23 May 1944 against two ships of a convoy of three AIC's escorted by three Chidori type torpedo boats. This two was a day periscope attack delivered from inside the screen. Six torpedoes were fired. The track angle was 110°; mean gyro angle 10° left, range 1700 yards to nearest target. Two ships overpaced and four timed hits were obtained, two in the near target of the Panama Maru class and two in the center ship of the convoy, a ship of the ORIU Maru class. Spread was ample and again the attack was made in the flat, glessy sea characteristic of this area. This also is considered a good attack.

Both attacks resulted in persistent depth charging, which, fortunately did little damage.

2. The Commanding officers comment in paragraph U, regarding the need for an efficient aircraft detector is concurred in. The urgent necessity for this is most important in this general area where surface patrol is conducted in the face of intense air coverage.

— page 167 —
3. On both contacts worthy of torpedo exenditure, CERC made aggressive and determined attacks, scoring hits in both instances. Alert and effective escort craft prevented remaining at periscope depth to witness damage: The Division Commander congratulates the Commanding Officer, officers and crew on a fine patrol, marked by skill, aggressiveness and persistence in the face of strong enemy counter measures.

C. C. BURLINGAY

— page 168 —
15/18A16-3/(11) SUBMARINE SQUADRON EIGHTEEN:
Serial 064
CONFIDENTIAL
SECOND ENDORSEMENT TO
Report of U.S.S.CERO
(SS225) Fourth War Patrol.

From: The Commander Submarine Squadron EIGHTEEN.
To: The Commander in Chief, UNITED STATES FLEET.
Via: The Commander Task Force SEVENTY-TWO.

Subject: U.S.S. CERO (SS225) - Fourth War Patrol, connotes on.

1. The remarks of Commander Submarine Division ONE EIGHTY-TWO are concurred in.

2. The material condition of the CERO is good. Her state of cleanliness was excellent. No major breakdowns or defects. Encounters occurred on patrol. The high number of replacements of the crew over the past year has been a source of satisfaction to the crew. It is suggested that the crew be given a special report on this subject. The crew is in good condition and is ready for further service.

3. The morale of the personnel is very high and their state of health excellent. The policy of the commanding officer commanding the patrol is to encourage the crew to maintain a high level of morale and to be ready for further service.

4. The patrol was well conducted. The aggressiveness, determination, and skill displayed in the two torpedo attacks is commendable. It is regretted that the special mission was not successfully accomplished because of circumstances beyond the control of the ship.

5. The Squadron Commander adds his congratulations and a hearty "Well Done!" to the personnel congratulations extended the commanding officer, officers, and enlisted personnel of the CERO by General MacArthur, for an excellent patrol and the damage inflicted upon the enemy.

— page 169 —
42
Serial: 0213
C-C-N-E-I-D-E-N-T-T
U.S.S. C.RO (SS225)
Fourth War Patrol
Report.

From: The Commander Task Force SEVENTY-TWO.
To: The Commander-in-Chief, UNITED STATES FLEET.
Via: The Commander, SEVENTH FLEET.

Subject: U.S.C. CERO (SS225) - Report of Fourth War Patrol - Comments on.

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

2. The fourth war patrol of the CERO was conducted in the area between Halifax and Falmouth. A special mission had been assigned but was not accomplished because of circumstances beyond control of the ship.

3. Only two contacts presented opportunity for attack. These were both convoys and CERO was aggressive and skillful attacks on both in the face of effective enemy anti-submarine measures.

4. The Commanding Officer's comments under radio indicate an intelligent use of the means at hand on the part of the CERO radio organization. An increase in the Japs efforts to jam both submarine fox schedules and ship to shore transmissions may be expected. In this event, it may become advisable during periods of severe interference to man two frequencies simultaneously.

5. This patrol is designated as successful for combat insignia award.

6. The Commanding Officer, officers and crew of CERO are congratulated upon the successful completion of an unusually lengthy and arduous patrol and on inflicting the following damage on the enemy:

DAMAGED

1. Preighter (Cheribon Maru) (BU)... 4,000 tons (attack No.1)
2. Preighter (Nanna Maru) (BU)... 4,000 tons (attack No.2)
3. Preighter (Oleitu Maru) (BU)... 7,500 tons (attack No.3)

RECEIVED S-G FLEET
23-22 2005
J.M. HAINES
JUN 26 19
JUN 26

— page 171 —
20 August 1944
SS225/AL6-3
Serial 011
C-O-N-F-T-D-R-N-T-I-A-L
DECLASSIFIED

From: The Commanding Officer.
To: Commander-in-Chief, United States Fleet.
Via: (1) Commander Submarine Division ONE EIGHTY ONE.
       (2) Commander Submarine Squadron EIGHTEEN.
       (3) Commander Task Force SEVENTY TWO.

Subject: U.S.S. CERO, Report of War Patrol Number Five.

Enclosure: (A) Subject Report.
       (B) Track Chart for Commander Task Force SEVENTY TWO.
       (C) Plots of Torpedo Attacks for Task Force SEVENTY TWO.

1. Enclosure (A), covering the fifth war patrol of this vessel conducted in the area around Mindanao between latitudes 4N to 7-30N and longitudes 123-30E to 130E during the period June 26, 1944 to August 22, 1944, is forwarded herewith.

DECLASSIFIED
BY OP-0982C
DATE 5/25/42
E. P. DISSETTE

DECLASSIFIED

— page 180 —
35225/AL6-3
Serial 011
CERTIFIED BY
Date: July 9
Time: 14:56
Height: 16,000 feet, 6 miles, needed for
barbed wire, 6 miles, needed for
surfaced and riz for depth
charge. (aircraft to be for depth

— page 181 —
225/16-3
Serial: 011
CC: TID: TLL
Date: July 12 1035
Date: July 14 0015
Date: July 14 0040

| Date | Text |
|------|------|
| 225/16-3 | For us, ant dscb, ri and for doth chrro. (..rort ft con tcs no. 21). It is difficult to deter in watch these lines, wh on w headed for us, a'vve seen se or just ha poned to hand our wg durin. rout inc arc cover re. othr. h e ben drc ped on us yet. |
| 1317 | Si htd dirr ft, unidentifid, 130°, macd scuth lor cost. (..rort cnt co no. 22). |
| 2107 | Saff cad. On -ins parrol. i on -sit. - i t. 05-03. |
| July 14 0030 | Pull used - 1302 16515. |
| July 14 0015 | Shtd sstl strl vcsel, 146 t, 6000 yds. - voltd. (..is oct ot -

— page 189 —
5225/16-3
Serial 011
CG/FIDIT/LI

Date: 22 July 1942
Time: 0745
Depth: 270°T and 120°T
Sq. m. bearings indicate. Ltrc zig to south.
2103 Estimate target course 170°T. Target sighted 15 kts and 0° to 130°T.
2141 Sighted 15 kts and 0° to 130°T. Slight zigzag to west. Conversed 12,000 yds and still no radar contact.
2117 For target course 14 kts, closing to 4°R range, and missed 4.5 kts. 6,000 yds to 120°T to close and overcast. Sighted 3 (3 foot swells with sonar). 6,000 yds to 120°T to close

— page 190 —
5/22/45 (SS225)
SS225/416-3
Serial 011
JOURNAL

Date: July 22 2137
Time: 2137
To: 2139
Received as per: 8 kts, c/e to 280°t.
Received as per: 12 kts closing range.
Received as per: 12 kts closing

— page 195 —
2058
USS SS225 (SS225)
SS225/AL6-3
Serial 011
CONDITIONAL
Date:  July 29 1850
Time (K)
Sighted Betty, bearing 310°, possibly returning to base after scouting
N. tri on her way.
Navigational pilot indicates that the cruiser passed within 2000 yds of the point we were patrolling all day. Unfrustrately we were sucked to the south by the trawler type escort. It is a-clear that the trawler came out well ahead of the cruiser and searched the escort to the S2 of the Capo. The cruiser probably came down the middle of the Gulf, an when the trawler reported all clear, the cruiser shot around the end of the Capo at 27 yds and headed for Fuku. Had we hold our critical course and speed and disregarded the trawler, we probably would have been well within range of the cruiser. At the first contact the trawler was not identified as such due to his being in a bright sun sector and due to the fogged condition of the periscope. (For further discussion of periscopes see section (K).)
2058
Surfaced. Sent enet et report on area frequency twice, blind, and then to CDF-72.
Nc on post - Lnt. 06-23N.
Lng. 126-17°.
Fuel used - 830
Miles started - 120
July 30 0644
Down dive. Periscope patrol off Capo San Augustin.
2058
Surfaced.
Nc on post - Lnt. 06-16N.
Lng. 126-15,5°.
Fuel used - 1030
Miles started - 119

-24- ENCLOSURE (AL)

— page 197 —
1319
Date: 2 1310
Time (K): 228°t
Target: 8 kts.
Estimated range: 12000 y's.
Target:
H.S. not begun sighted.
C/o t: 220°t t. cl. 5500 yds.
tilted listance to: tr.ck 5500 yds.
This c.ure sh.ul. l.ose track to
about: 2000 y's. at firing point.

1328
Sight.tol. target bearing 243°t.
Un.ble t. btain range due t. haze
or fog. vr. tr.ck. (Ship c. n. at
n. 17). T. r.gt. is a single stack
v.assol., aking s. k. r.rid.ically.
The. stack appears t. b. point. a
light. gr.on. c.llr. Very. difficult
t. sc. The. l.acing. sc.ort. is a
chi.ri. n. and. there. is. t. l.ast. no
that. sc.ort. tr.ck. which. is. a
convert. tr.ck. for. CO. type. alth.ough
it. w. s. n.ver. son. clearly. There. are
t. l.ost. 2. a.fer.rt. ser.oning: one
T. to. sight. to. b.fore., and. one. Betty(?)
type.

1329
C/o t: 250°t t. further. close. the
track. R.ice. fr. s.il.ent. running
when. sun. t. report. se.rews. of. ne.
c.ost. r. had. st. ppad. This. one. w. s.
n. t. p.inging. c.nsistently. and. it. was.
sur.rised. he. was. listening. at. this
point.

1336
D.ught. a. gl.ir.nes. of. Chi.eri. be.ring
267°t. Unable. to. see. t. r.gt.

1340
C/o t: 280°t, port. ch.oad 2/3.

1343
D.ught. a. gl.ir.nes. of. tr.gt. bearing
280°t, angle. on. new. about. 100. star-
board, indicating. target. c.urse
changed. t. n.rt.h, but. this. was. not
consider. a. c.rm. at. the. time. Our
c.st.rict. w. s. that. he. w.ul. a/c. to. 020°t
on. r. und.ifg. B.ans. Pt, but. since. we. did
were. un.ble. to. see. the. land. we. did
n. t. know. where. he. w. s. in. relation. to.
the. point. Our. navig.ati. nal. position.

-26- -TCLOSURE (.)

— page 203 —
1213: SS225/A16-3
Serial 011
CONFID: ITAL
Date: Aug. 5
Time(K): 1213
SS: 50 rpm.
So conditions:
flt. salt, oily surface. Brilliant sunshine. Very poor norisocp weather, as usual. Still swinging right slowly to our in for about 90 starboard trck, when target zigged left.
1214: Left full rudder, starboard ahead 2/3, t. 1st Chri. pass ahead at 1000 yds, and to come to best trck. Target steadied down on 180’t.
1218: Steadied on course 100’t for 80 starbrd trck, range 1000 yds.
1219-15: Our most firing six torpedoes. (T.rad attack nr. 2): as tho third trpods was fired target onced zig to right. Ornarked jt. TDC a course change of 45’ to his right while firing 4,5, and 6, continuing firing because of short range.
1219-47: Hard first of fur torpedo hits, and our swing right, risepc back to target (1.

— page 212 —
15.1721 1: trawler: 16000 06-17N P 00: 0-1kts: moving w/air traffic through. (CL In
: July 29: escort: yds 126-16E: 00: 0-1kts: moving w/air traffic through. (CL In
: 16.1825 1: CL 20000 06-13N P 00: 0-1kts: moving w/air traffic through. (CL In
: July 29: (N/TORI yds 126-15E: 00: 0-1kts: moving w/air traffic through. (CL In
: 17.1325 CONV Y 12000 05-55N JK 00: 0-1kts: moving w/air traffic through. (CL In
: Aug 2 1: medium: yds 125-43E: 00: 0-1kts: moving w/air traffic through. (CL In
: : JK 00: 0-1kts: moving w/air traffic through. (CL In
: : 1: 00: 0-1kts: moving w/air traffic through. (CL In
: 18.1507 6: very 1200 05-55N JK 00: 0-1kts: moving w/air traffic through. (CL In
: Aug 3 small 00: 0-1kts: moving w/air traffic through. (CL In
: : (250 ton-: 00: 0-1kts: moving w/air traffic through. (CL In
: : (ners) 00: 0-1kts: moving w/air traffic through. (CL In
: 19.0735 Tugboat 10000 05-51N P 00: 0-1kts: small coastal traffic headed for
: Aug 4 1: small 00: 0-1kts: small coastal traffic headed for
: : (250 tons): 00: 0-1kts: small coastal traffic headed for
: 20.0903 Sampan 8000yds: 05-52N JK 00: 0-1kts: small motor sampan apparently headed for
: Aug 4 00: 0-1kts: small motor sampan apparently headed for
: : 125-43E: 00: 0-1kts: small motor sampan apparently headed for
: : 8 kts: Davao. Avoided.

— page 214 —
1 2 3
Date: June 28: Jun 28: June 29
S
Time (Zone): 0525 : 2040 : 1100
B
Position: Lat. : 0-18.5N : 01-37N : 02-33N
M
Long. : 125-58E : 136-59E:135-52E.
A
Speed : 14 : 14 : 14
R
Course : 288 : 28E : 286
I
Trim : Surf. : Surf. : Surf.
E
Minutes Since Last
SD Radar Search : 0 : 0 : 0
Number : 1 : 1 : 1
A
Type : Unknown : Unknown:Unknown
I
Probable Mission : Pat. : Pat. : Fgt.
R
How Contacted : SD : SD : SD
C
Initial Range : 27 mins. : 17 mins : 4 mins.
A
Elevation Angle : -- : -- : --
F
Range & Relative
T
Bearing of Plane
When it Detected S/Mi : Unk. : Unk. : Unk.
(State(Beaufort) : 1 : 1 : 0
C
Sea: (Direction(Rel) : 028 : 029 : --
D
Visibility(Hills) : 10 : 30 : 20
I
T
Clouds: (Percent
O
Overcast : 90% : 70% : 70%
N
S
(Bearing(Rel) :
Moon (Angle
(Front
Illum. : 90% : -- : --
-43- ENCLOSURE (A)

— page 215 —
4 5 6
Date: June 29: June 30: June 30
U Time (Zone): 2132: 1259: 1800
B Position: (Lat.): 3-09N: 4-12N: 4-40N
A Course: 286: 305: 305
N Trim: Surf.: Surf.: Surf.
Minutes Since Last
SD Radar Search: 0: Scoured: Scoured
Number: 1: 1: 1
A Type: Unknown: B-24: Bomber
IR Frobabl. Mission: Fat.: Fat.: Fat.
C How Conducted: SD: Sight: Sight
R Initial Range: 14 mis: 13 mis: 10 mis
A Elevat. Angle: --: --: --
T Range & Relative
Bearing of Plane
When it Deceived S/il: Unk. : ND : ND

(State (Beaufort): 1: 1: 1
C Sea: (Direction (Pcl): 074: 010: 010
D Visibility (Miles): 15: 20: 25
T Height in Pt.:
T Clouds: (Forecast
O Overcast: 60%: 80%: 80%
S (Bearing (Acl): :
Moon: (Angle
(Porcent
Illum.: 100: --: --: --

— page 217 —
10 : 11 : 12 :
Date : July 7 : July 8 : July 8
Time (Zone) : 1545 : 0937 : 1203
Position: Lat. : 5-47N : 5-54N : 5-53N
Long. : 125-43 : 125-47 : 125-47
Spccd : 3 : 3 : 3
Course : 220 : 040 : 240
Trim: : Per. : Per. : Per.
Injntos Since Last
SD Radar Search : -- : -- : --
Number : 1 : 1 : 1
Type : :Mavis : adam : adam
Probable lission : Pat. : Pat. : Pat.
How Contested : Per. : Per. : Per.
R Initial Range : 10 mis : 8 mis : 3 mis.
T Length : -- : -- : --
Range & Rcltive
Bearing of linc
When it Detected S/N : ND : ND : ND
(State(Beaufort) : 2 : 1 : 1
Sea: (Direction (Rol) : 270 : 225 : 225
Visibility (Miles) : 12 : 14 : 15
Clouds: (Height in Ft.): 8000 : 2000 : 3000
(Percent
Overcast : 80% : 100% : 100%
( Bearing (Rcl)
S Moon: (Angle
(Percent : -- : -- : --
Illum.

-46- INCLUSURE (A)

— page 218 —
13 : 14 : 15 : 16

Date: July 8 : July 9 : July 9 : July 9
Time (Zone): 1503 : 1905 : 1437 : 1456
Position: Lt. : 5-43N : 5-50N : 5-50N : 5-50N
Long. : 125-43E : 125-45E : 125-36E : 125-35E
Speed : 3 : 3 : 3 : 3
Course : 270 : 120 : 220 : 160
Trim : Per. : Per. : Per. : Per.
Minute Six Inch Lst. :
SD Radar Search : -- : -- : -- : --
Number : 1 : 1 : 1 : 1
Type : .adam : .livis : .navis : .adam
Probable Mission : Pat. : Pat. : Trans. : Pat.
How Contacted : For. : Per. : Per. : Per.
Initial Range : 8 mis : 6 mis : 6 mis : 6 mis
Trouble : -- : -- : -- : --
Range & Relative
Bearing of Plane
When it Detected
S/N : ND : ND : ND : ND

(State
(Baufort) : 1 : 1 : 1 : 1
Sea: (Direction(Rel): 170 : 170 : 250 : 250
Visibility(Hills) : 15 : 15 : 10 : 10
Height
in ft.) : 5000 : 6000 : 6500 : 7000
Clouds: (Torrent
Overcast : 100% : 100% : 70% : 70%
(Rearing
(Roll)
Moon : Angle
Torrent
Illum. : -- : -- : -- : --

-47- ENCLOSURE (..)

— page 219 —
17 : 18 : 19 : 20
Date : July 12 : July 12 : July 12 : July 12
S
U
B
H
R
N
R
C
R
S
R
A
R
I
N
E
R
T
R
A
N
T

— page 220 —
21 : 22 : 23 : 24
Date: July 12; July 12; July 15; July 16
S Time (Zone): 1035 : 1317 : 0952 : 1507
U Position: Lat.: 6-36N : 6-36N : 4-21N : 5-46N
B Log.: 12-12N: 12-52E : 12-27E : 12-50E
R Spced : 3 : 3 : 14 : 3
R Course : 270 : 180 : 160 : 315
N Trim : Tor. : Tor. : Surf. : Per.
E Limits: 3-6
SD Radar Search: --

— page 221 —
25 : 26 : 27 : 28
Date: July 17: July 17: July 21:July 21
S Tino (Zone): 1235: 1747: 1018: 1447
U osition: Lat. : 5-42N : 5-45N : 7-21N : 6-46N
B : 124-473: 124-54E : 129-01:129-21E
H : 3 : 3 : 13 : 13
Spoed : 315 : 280 : 030 : 150
R Course : Tor. : Tor. : Surf : Surf.
I Trin : 1 : 1 : 1 : 1
E Minutes Sinc Lst : 1 : 1 : 1 : 1
SD Iad r Surch : 10 nis : 10 nis : 10 nis : 15 nis
Number : 1 : 1 : 1 : 1 : 1
Type : .drm : Ruth : U.S. : Unident.
    : 1 : 1 : 1 : 1 : 1
T Range & Relative
Bearing of Ila
When it Detected
S/: : ND : ND : ND : ND : Unk.

(State
Beaufort) : 1 : 1 : 2 : 2
Sea: (Direction
(Call) : 225 : 230 : 080 : 195
Visibility (Miles) : 5 : 5 : 15 : 15
D
I (Height in
Pt. : 5000 : 4500 : 7500 : --
I Clouds: (Correct
O Overcast: 100% : 100% : 80% : 50%
N
S (Bearing (Aol)
Room: (angle
(Arcent
Illum. : --

— page 222 —
29 : 30 : 31 : 32
Date: July 22: July 23: July 24: July 25
Time (Zon.): 11:03: 11:17: 11:30: 11:28
Position: Lat.: 5-55N: 6-58N: 5-41N: 5-50N
Long.: 129-52E: 126-40E: 129-18E: 125-39E
Spocd: 18: 14: 14: 14
Course: 25: 04: 225: 000
Trin: Surf: Surf: Surf
Minutes Since Last
SSU under Search: 0: Secured: Secured: Secured
Number: 1: 1: 1: 1
Type: Unident: U.S.: Unident: U.S.
T: 1: 1: 1: 1
Robable Mission: Rec.: Tnt.: Lat.: Pat.
How Conducted: S

— page 223 —
33 : 34 : 35 : 36
Dato : July 29 : July 31 : Aug 2 : Aug 2
Tinc (Zone) : 1825 : 0925 : 1020 : 1048
Position: L.t. : 6-7N : 7-3N : 5-51N : 5-25N
Long. : 126-162 : 127-303 : 125-312 : 125-293
Spoud : 3 : 14 : 3 : 3
Course : 190 : 020 : 300
Trin : .or. : Surf. : .or. : .or
Minutes Since Last
SD Radar Search : -- : Securord : -- :
Number : 1 : 7 : 3 : 1
Type : Botty : Sally : Auto : Botty
Tracable Mission : Bso. : Trans. : Iat. : Iat.
How Cont.cted : .or. : Slight : .or. : .or.
Initial Range : 10 nis : 15 ris : 10 ris : 10 ris
Elev. tion angle
Range & relative
Bearing of line
in it Detected
S/N : ND : ND : ND : ND

(State
(Beaufort) : 2 : 2 : 2 : 2
Sea:
(Direction(rel: 225 : 000 : -- : 270
Visibility(ils) : 5 : 10 : 5 : 5
Height in
ft. : 6000 : 7000 : 4000 : 4000
Clouds:
(arcent
Overcast : 60% : 50% : 100% : 100%
(Bearing(hel)
Ison: (angle
(arcent
Illum. : -- : -- : -- : --

— page 224 —
37 : 38 : 39 : 40
Date : .ugz 2 : .ug 3 : .ug 4
Time : 1307 : 1217 : 1420 : 0112
Location : 5-5SN : 5-58N : 6-1N : 5-1N
B Length : 125-44E:125-43E:125-44E:125-11E
Speed : 3 : 3 : 3 : 10
Course : 200 : 000 : 000 : 180
Trip : : or : or : or : Surf
Minutes Since Last
SSID: 5D Indir Search
Number : 1 : 1 : 1 : 1
Type : :Nato : :auto : :Botty : :Unknown
Probable Mission : Esc :

— page 225 —
41 : 42 : 43 : 44
Date : aug 4 : aug 5 : aug 9 : aug 9
Triton (Zero) : 0614 : 1050 : 0140 : 0411
Position: Lat. : 5-31N : 5-12N : 5-5N : 05-5N
Long. : 125-13E:125-36E:126-42E:127-7E
Speed : 3 : 3 : 10 : 10
Course : 310 : -- : 085 : 085
Trin : or : or : Surf : Surf
Minutes Since Last
SD Radar Search : -- : -- : 0 : 0
Number : 1 : 1 : 1 : 1
Type : N:No : D:No : Unident:Unident
Re:able Mission : 2sc : 2sc : 1t : 1at
How Cont:std : 2r : 2r : 5 : SD
Initial Range : 8 nis : 10 nis : 15 nis : 14 nis
Range & Altitude
Bearing of Plane
Than it Detected
S/ii : ND : ND : UNK : UNK

(State
(Boufort) : 2 : 1 : 1 : 2
Sea:(
(Direction(ici): 260 : 230 : 180 : 180
Visibility(Hills) : 5 : 10 : 5 : 5
Height in
Pt. : 6000 : 6500 : 6500 : 6500
Clouds: (
(-orcent
Ovorc.st : 90% : 60% : 90% : 80%
(Bearing(ici)
Moon:(-ngle
(-orcent
Illu. : -- : -- : 50% : 50%

-54-

— page 227 —
49 : 50 : 51

Date: : aug 11 : aug 13 : 0700 : 1214 : 0635
S
U
B
: : 02-25R : 00-37N : 00-31S
: : 13-08 : 185-08E : 143-07
: : 13.8 : 13.8 : 13.8
: : 109 : 109 : 106
: : Surf : Surf : Surf
: : 0
: : 1 : 1
: : Undict : B-24 : Undent
:

— page 229 —
1 : 2 : 3 :
Tubes Pired : 1 2 : 3 :
Truck angle : 132 : 133 : 133
Gyro angle : 350 : 346 : 349
Depth gear : 4 : 4 : 4
Lower : Hi : hi : Hi
Hit or Miss : Miss : Miss : Miss
Articulation Set (No) : No : No : No
Mark Torpedo : 14-3A : 14-3A : 14-3A
Serial No. : 26416 : 39233 : 25873
Mark Exploder : 6-5 : 6-5 : 6-5
Serial No. : 11477 : 13264 : 13340
Actuator Set : C: intact : C: intact : C: intact
Actuator not actual : -- : -- : -- : -- :
Mark Warhead : 16-1 : 16 : 16-1
Serial No. : 10429 : 2911 : 9995
Explosive : TX : TX : TX
Firing Interval : 0 : 7s : 15s
Type Spread : 1/16 R. : 1/4 L : 1/2 R
Torpedo run : 4750 : 4700 : 4690
Sea Conditions : 3 : 3 : 3

(verhaul activity : U.S.S. : USS : S/n Report
    : Buryal : Fulton : Unit
    : Navy 134

Continued on next page.

— page 230 —
4 : 5 : 6
Track angle : 135 : 133 : 135
Gyro angle : 347-30 : 349 : 346
Depth: : 4 : 4 : 4
Power : HI : HI : HI
Hit or Miss : Miss : Miss : Miss
Particle (yes or no) : No : No : *Yes
Mark Trope : 14-3m : 14-3m : 14-3m
Serial No. : 39152 : 26379 : 23367
Mark Exploder : 6-5 : 6-5 : 6-5
Serial No. : 4461 : 13245 : 1505
Rotation set : Contact : Contact : Contact
Rotation actual : -- : -- : --
Mark Wheel : 15-1 : 15-1 : 16-1
Serial No. : 5711 : 2136 : 11405
Explosive : TNT : TNT : TNT
Firing Interval : 228 : 30s : 37s
Type Spread : 1 L : 3/4 n : 1-1/4 L
Torpedo Run : 4660 : 4650 : 4610
Sea Conditions : 3 : 3 : 3
Vessel activity : S/M: ordir:USS : S/M: opr:ir
Unit Navy : FULLT.N : Unit Navy
: 134 : : 134.

Note: U.S. Navy LNO radar routine of fully ready torpedoes.

*Upon ejection 16 torpedoes (23367) was neither seen nor heard. Believe it sank at firing point.

Believe torpedoes ran under targets which were shallow draft ships.

-59- ENGLISH (4)

— page 232 —
SS225/AL6-3
: Serial 011
: CONFIDENTIAL
: (1) ATTACK DATA
: U.S.S. CHRO TORPEDO ATTACK NO. 2, PATROL NO. 5.
: Target draft: 25' Course 180-225 Speed 8
: Range 900 yds (at firing).
: Own Ship Data
: Speed 3 Course 100 Depth 65 ft.
: Fire Control and Torpedo Data
: Type Attack: Day periscope, small gyro angles, average track angle 70 stbd, TDC uned, 14° divergent spread, fired 1 and 3 on periscope bearings, 2, 4, 5, 6 on generated bearings.
: Depth set 8 feet, average torpedo run 700 yds.

-61- ENCLOSURE (A)

— page 233 —
1: 075: 079: 080
: 2: 339-30: 344: 340-30
: 3: 8! : 8! : 8!
: 4: Hi : Hi : Hi
: 5: Hit : Hit : Hit
: 6: No : No : no
: 7: 14-3A : 14-3A : 14-3A
: 8: 25297 : 26410 : 25907
: 9: 6-5 : 6-5 : 6-5
: 10: 12750 : 2130 : 8136
: 11: Contact : Contact : Contact
: 12: Contact : Contact : Contact
: 13: 16 : 16 : 15-1
: 14: 4.576 : 2600 : 2147
: 15: FX : TFX : TNT
: 16: 0 : 08s : 16s
: 17: 1-1/4L : 1-1/4LR : 4 L
: 18: 840 : 800 : 770
: 19: 0 : 0 : 0
: 20: : 22 : S/M Repair
: 21:

— page 234 —
1. USS CERO (SS225)
: Serial 011
: CONFIRMANT: L
: (I) HINES
: Non-son.
: (J) INSULAR RIN 2 M.SURFS AND DIVISION TACTICS.
: The 1/5 vessels encountered by the CERO's
: only submerged attack complex, a listening-
: dropping team which lost contact shortly after
: the attack began. Although sound conditions
: were excellent we were able to overtake at 80
: rpm's to 300 ft. without detection.
: This was the beginning of a long-range
: after losing contact and kept up a search for
: at least one and half hours. No new counter-
: measures were tried. Scorps were made by plic-
: ing the escorts astern, and running silent at
: 80 rpm under 2 to 3° temperature layer,
: depth 300 ft. Some of the early attacks made
: were quite close but no serious damage resulted.

(K) LIGHT DETECTORS AND DIALOGUE:
: (1)

— page 245 —
2ND
CONFIDENTIAL
FIRST ENDORSEMENT to
U. S. CERO (SS225) Report of
W. P. Patrol Number Five.

V: The Commander Task Force SEVENTY-TWO.
T: The Commander-In-Chief, UNITED STATES FLEET.
a: The Commander, SEVENTH FLEET.

Subject: U.S.S. CERO, Report of War Patrol Number Five.

1. CERO's Fifth War Patrol was spent in areas off Southern
   MINDANIA. Five contacts worthy of torpedoes were made. Two attacks were
   made, one of which resulted in the sinking of a SIRETOKA type tanker.
   This attack was aggressively driven home in spite of surface escorts and
   air cover.

2. Other high spots of the patrol include two high speed contacts,
   both of which CERO was unable to close. The first contact was on 1 July with
   a battleship and 2 destroyer escorts; the other, on 29 July, consisted of a
   NATORI class light cruiser and 1 destroyer. Contact reports in both instances
   were promptly made.

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

4. The Task Force Commander congratulates the Commanding Officer,
   officers and crew of the CERO on the completion of a successful patrol,
   during which the following damage was inflicted upon the enemy:

SUNK

1 A0 (SIRETOKA Type) (EC) ...... 8,000 tons.

DISTRIBUTION:
ComInCh (3-direct) CSS-4, 6, 8, 10, 12,
VCNO (2-direct) 14, 16, 18, and 20.
VONAV (Op-23c) CSD-53, 181, and 182
ComIstFlt CinC, S/M Sch. N.L. Conn. (2)
Com2ndFlt Flt. Radio Unit, M/SLOURNE
Com3rdFlt ALL SS TP-72 (May be taken
ComSubsbltFlt (25) but BURN prior entering
ComSubsbltFlt (25) CO USS CERO.

P. P. HURRY,
Force Secretary.

180

-1-

— page 246 —
29 OCT 1944

CONFIDENTIAL

SECOND ENDORSEMENT to:
CO, U.S.S. CEROC (SS225)
Conf. Ltr. serial 011
of 20 August 1944.

From: Commander Seventh Fleet.
To: Commander in Chief, United States Fleet.
Subject: U.S.S. CEROC (SS225) - Report of Fifth War Patrol.

1. Forwarded.

J.H. LONG,
By directions.