[Bubblehead1980]

TMO 2.5 Update BH
100 difficulty, cams off, contacts on.

Just finished my first "non test" patrol in the TMO 2.5 update. I am pretty happy overall. Quite the challenge.

USS Seal SS-183
War Patrol Report
First War Patrol
14 December 1941- 6 January 1942


(A) Prologue

Arrived Manila from Pearl Harbor Monday 10 November 1941 , 1100 hours. Commenced voyage repairs and liberty for crew, followed by training in preparation for forthcoming order.

After attack on Pearl Harbor, T.H., and invasions of Philippines, Guam, and Malaya, by Empire of Japan, War declared by Congress on Monday 8 December 1941 (Tuesday 9 December local). Orders to conduct unrestricted submarine warfare issued 8 December (local) . Preparations for war patrol commenced immediately with provisioning of boat.

Twenty two MK 14 torpedoes, 180 rounds of 3" 50 Caliber Ammunition, and 1200 rounds 20 MM ammunition, loaded. Survived Cavite Air Raid by enemy on 10 December with no damage. Sea Lion SS-195 damaged beyond repair.

All torpedoes and provisions loaded by 1600 13 December 1941.Ready for sea 14 December 1941.

Crew Roster as of 14 December 1941

Officers

LTCDR K.C Hurd, USN. CO
LT. I.T. Ryan, USN. XO/Navigator
LT. jg B.R.P. Digby, USN Dive Officer
Ens. M.L. Lynch, USN. Torpedo Officer/TDC Operator
Ens. D.B. Thompson USN. Engineering Officer

Chief Petty Officers

CTM R.I. Madison, USN. Chief of the Boat
CMMoMM D.R. Saunders, USN.
CTM S.W. Garcia, USN.
CMoMM V.W Ballantine, USN.
CMoMM D.K. Bush, USN.
CMoMM E.K. Street, USN.




(B) Narrative


Sunday December 14, 1941

0400 Departed Cavite Navy Yard, P.I. for First War Patrol.

0405 Course 240 Speed 11 knots to exit Mania Bay.

0705 Exiting Manila bay, Sighted unidentified US Tambor submarine returning. Bearing 083 range 9000 yards. 14-15 N 120-26 E.

0707 Increased speed to 18 knots to clear area.

0920 Submerged to 100 feet. 4 knots. Course 310.

2100 Surfaced. Recharge batteries.

2340 Night orders: Maintain course 000 standard speed en route patrol area off Cape Bojeador, P.I. Seal passed Cape Boliano during the night. Extra vigilance paid due to enemy activity in Lingayen Gulf and Vigan areas.



Monday December 15, 1941


0615 Trim Dive to 90 feet.

0631 Surfaced. Course 010 15.5 knots en route patrol area.

0730 Submerged to 100 feet. Course 010 3 knots.

1800 Surfaced. Recharge batteries

2340 Night Orders: Maintain course 025 speed 15.5 knots. Expected ETA to assigned area 0145.


Tuesday December 16, 1941

0009 Position 19-3 N 120-27 E. Arrived in patrol area earlier than expected.

0437 Submarine spotted bearing 346 7250 yards. Estimated course/speed 11 knots. Position 19-5 N 120-47 E

0439 General Quarters-Torpedo.

0528 Morning twilight. Submerged for attack. Estimated 8000 yards ahead of submarine.

0543 Contact identified as US Tambor Class submarine. Went to 200 feet, ordered course 000 to open range.

0600 Secured General Quarters.

0700 Lost Sound contact.

1830 Surfaced. Recharge Batteries.

2340 Night Orders: Conduct box search pattern at 14 knots in Luzon Straits 150 NM west of Balabac Islands.


Wednesday December 17, 1941

0745 Submerged for patrol.

1215 Sound has distant, fast props. Turned to course290 at 5 knots to investigate.

1233 Sound contact bearing 019, closing, medium speed, estimated range 5.5 NM.

1234 Periscope observation: Visual sighting of possible two enemy destroyers bearing 015 9000 yards.

1239 General Quarters-Torpedo.

1330 Secured General Quarters. Unable to close destroyers as turned to NW at high speed.

1809 Surfaced. Recharged batteries.

2340 Night Orders: Maintain patrol of LuzonSstraits at 14 knots.



Thursday December 18, 1941


0755 Submerged for patrol.

1338 AIRCRAFT CONTACT NO. 2 Bearing 047 7000 yards, closing. Ordered 200 ft depth.

1830 Surfaced. Recharged batteries.

2340 Night Orders: Maintain patrol at 14 knots.


Friday December 19, 1941


0759 Submerged for patrol.

1830 Surfaced. Recharge batteries.

2340 Night Orders: Patrol at 14 knots.


Saturday December 20, 1941

0600 Trim Dive.

0630 Surfaced for patrol.

1325 Smoke spotted on horizon bearing 355 estimated range 10 NM. Ordered flank speed to close contact.

1332 Contact is ship. Course 260 Est speed 7 knots.

1340 General Quarters.

1417 Submerged for attack.

1514 Fired two MK 14 torpedoes at target.

1515 Torpedo # 1 initially judged as hit, but now believed to have detonated 5-10 feet from target instead of under the keel as aimed. Torpedo #2 impacted amidships as aimed. Target damaged and listing to starboard.

1634 Surfaced to move ahead of target for follow up.

1802 Received message to shift port to Surabaya, Java from Manila due to air raids.

1830 Secured General Quarters.

2100 Unable to reestablish contact with target in dark. Running down various courses.

2120 Result of attack: AKITA MARU 3900 tons damaged.


2126 Looks spotted unknown vessel bearing 339 range estimated 7600 yards. General Quarters.

2127 Vessel is a destroyer.

2133 Lowered sound heads. Sound check reveals multiple sound contacts.

2134 Convoy Sighted. 19-24 N 118 57 E Estimated Speed/Course 183 degrees. 12 knots.

2234 Submerged for attack in front of convoy. 250 ft depth, silent running to work between two escorts

2253 Periscope depth in what appeared to be large convoy of troopships. Possible landing force. Ship at 090 1100 yards. Moved forward for attack on next column.

2255 All tubes ordered ready.

2321 Fired two MK 14 torpedoes from stern tubes #5 and #6.

2325 Both torpedoes missed.

2337 Fired four MK 14 torpedoes, three hits.

2238 MOMOYAMA MARU 4037 tons sunk at 19-17 N 118-48 E.



Sunday December 21, 1942

0000 Pinging, escort closing.


0002 DC explosion, above.


0020 Lost contact with escort.


0100 Secured General Quarters.


0300 Surfaced. Pursuit course 183 Speed 15.5 knots while recharging batteries.

0530 Turned to course 160. Believe convoy was invasion force heading for Luzon.

0546 Destroyer sighted bearing 000. Convoy is heading 157 9 knots. Appeared bound for Lingayen Gulf.

0912 Visual contact with convoy.


0930 General Quarters-Torpedo


0940 5.5 NM in front of convoy, shell splashes landed 1000 yards off port quarter. Submerged to avoid.

0942 Enemy Destroyer, closing fast 170.

0947 DD identified as Shiratsuyu Class.

0953 Two Subchasers closing as well, fast.

0954 DD pinging.

0958 Fired one MK 14 torpedo "Down the Throat" of DD from 700 yards, ordered 250 ft. Rigged for Depth Charge and Silent Running.

0959 DD overhead. DC splashes.

1000 DC explosions, close. Boat shaken. Damage and injuries (See Damage Section, DC Attack #2) Minor flooding in conning tower.

1003 Conning tower flooding controlled.

1054 Pinging.

1118 Pinging. Escort appears to have steady contact.

1121 DC explosions, close.

1123 Depth 270 ft.

1300 Secured General Quarters. Enemy escorts remain in area covering the convoys withdraw.

1904 Lost contact with escorts.

2137 At periscope depth, discovered neither No.1 nor No.2 periscopes functional, must have been damaged in attack.

2145 Surfaced. Damage control party began work on periscopes. Radio antenna also in need of repair.

2340: Night Orders: Maintain course 340 15.5 knots. Avoid contacts until repairs completed.



Monday December 21, 1941


0301 Repairs completed. Periscopes functional.

0302 Received Flash Traffic Warning of Japanese landings at Lingayen Gulf. Seal ordered to continued patrol of Luzon Straits.

0825 Submerged for patrol.

1555 Aircraft spotted bearing 171 3000 yards. Est altitude 1200 feet. Ordered 200 feet, emergency.

1830 Surfaced. Recharge Batteries.

2340 Night Orders: Maintain patrol in area at 14 knots.


Tuesday December 22, 1941

0800 Submerged.

1830 Surfaced. Battery recharge.

2316 Lookouts spotted enemy vessel bearing 355 degrees 5800 yards. 20-52 N 119-7 E

2317 General Quarters Torpedo. Targets identified as two destroyers course 334 16 knots.

2318 Submerged for attack.

2324 Stern tubes ready.

2326 DD identified as Kamikaze Class.

2327 ATTACK NO. 3 Fired three MK 14 torpedoes.

2329 Torpedo hitting time passed. Enemy searchlight spotted. Enemy alerted. Torpedoes missed. Sound had torpedoes hitting target, believe passed under target.

2330 Pinging.

2331 Escort closing bearing 100. Ordered 250 ft depth. Rigged for Depth Charge and Silent Running.

2333 Pinging.

2335 DD overhead. Splashes

2336 DC explosions.

2337 Second DD pinging along port side.

2338 DC explosions.

2339 Pinging. Escorts seem to have fix on the Seal.

2342 DD overhead. Splashes.

2343 DC explosions. Ordered 270 ft.

2348 Depth: 275 ft.

2349 DD overhead.

2350 Very close depth charge. Boat shaken.

2352 DD passed overhead. DC explosion

2356 Pinging. One DD ovehread.DD splashes. Boat Depth: 280 ft

2357 DC explosion.

2358 DC explosions. Close. Boat shaken.



Wednesday December 23, 1941

0000 Depth:300 ft. Speed 3 knots Course 120.

0003 Pinging.

0004 DD overhead. Splashes

0005 DC explosions

0008 DC explosions.

0012 Pinging.

0014:34 DD overhead.

0014:51 DC explosions.

0017 DC explosion.

0019 DC explosions, close. Boat shaken.

0021 DC explosions, astern.

0025 DD overhead.

0026 DC explosions.

0039 DD's went quiet, no sound contacts. Likely listening. Boat Depth: 347 feet.

0053 One DD audible on sound, moving away.

0133 Sound reported two contacts moving away, fast. Bearing 200.

0230 Secured General Quarters.

0325 Periscope depth. All clear on visual and sound. Secured Silent Running.

9330 Surfaced. Battery Recharge. Night Orders: Patrol area at 14 knots.

0404 Received Flash Traffic warning of invasion force approaching Lamon Bay, Philippine Islands.

0810 Aircraft spotted bearing 213 6 NM closing fast! DIVE ! emergency depth 200 ft ordered. Position:21-3 N 118-51E

0811 Boat passing 44 feet. Two large explosions from aerial depth charges astern. No damage.

1105 Periscope depth. Submerged Patrol.

1458 Sound has many props, heavy and fast bearing 121 long range. Course to 265 towards contacts.

1503 Surfaced to close contacts.

1508 Aircraft Spotted! (Large four engine flying boat) Bearing 323 5.5 NM Dive, 200 feet emergency!

1510 Explosions overhead.

1600 Surfaced. Course350 to intercept sound contacts.

1709 Enemy Task Force spotted. 21-15 N 118-147 E Estimated Course/Speed 005 degrees 17 knots.

1712 Aircraft spotted ! (Twin engine bomber type) 011 9000 yards closing fast ! . DIVE ! Emergency to depth 200 ft.

Bombs dropped by aircraft, landed astern, 50 yards.

1715 Sound reports warship closing, very high speed, bearing 342 long range. Believe aircraft reported Seal's presence.

1716 Second warship contact closing at high speed bearing 014.

1745 lost warship contacts, sound clear. Unable to surface due to aircraft presence.

1836 Surfaced. Recharged batteries.

1844 Almost out of assigned area. Turned to course 145 degrees.

2135 Spotted two patrolling enemy destroyers. 20-57 N 119-5 E Course 170 speed 16 knots. Avoided patrol.

2203 Proceeding to Lamon Bay, P.I. Reports of enemy invasion forces in area.

2340 Night Orders: Continue course 119 speed 15.5 knots to Bashi Channel en route to Lamon Bay, P.I. area.



Thursday December 24, 1941


0856 Increased speed to 18.5 knots while transiting Bashi Channel area.

0935 Ship spotted ! Bearing 260 degrees 8 NM. 2-0N 121-39 E in Bashi Channel. Estimated course/Speed 270 degrees 7 knots.

0936 General Quarters-Torpedo.

0943 Two destroyers spotted! Bearing 350 5 NM closing fast! Possible escort rendezvousing with merchant spotted at 0935/ Turned to avoid.

0948 AK turned to SW course enabling submerged approach. Submerged for attack.

1030 Periscope depth. DD's did not join the AK, likely a patrol not escort. AK is zigging on course 265.

1034 Observation. Target identified as SEIA MARU 7590 tons.

1047 All bow tubes made ready.


1055 Target spotted scope, turned away. Fired MK 14 torpedo from 800 yards.

1056 Torpedo impacted target. Fired second torpedo from 700 yards astern.

1057 Torpedo impact! Large fire burning on target. Target settling in water.

1058 Sound reported target engines ceased.

1059 Observation reveals target has large deck guns forward and aft, appear to be 4 or 5 inch guns.

1107 Target topside fires extinguished. Target dead in water.

1118 Fired one MK 14.

1119 Torpedo impact amidships. Large explosions.

1120 large topside fires and secondary explosions. Ship sinking by stern

1121 SEIA MARU 7590 tons sunk at 19-58 N 121-33 E.

1122 Sound has warships inbound high speed bearing 110! Likely DD's spotted previously responding to SOS from SEIA MARU.

1125 Depth 150 ft. Secured General Quarters. Course 090 3 knots.

1130 Enemy DD's in area of sinking, dropping depth charges.

1627 Sound contact. Warship Bearing 307 Closing, increasing speed.

1634 Two warships now on sound at 305.

1635 Periscope depth . Two destroyers spotted at 8000 yards.

1645 Destroyers closing at very high speed towards Seal. General Quarters. Rigged for Silent Running and Depth Charge. Ordered Depth 250 ft.

1649 Pinging.

1651 DC charges, overhead.

1652 More DC explosions. Damage reported (See Damage Section.) Boat depth. 300 ft

1653 Second DD overhead.

1654 DC explosions, close. Boat shaken.

1656 Depth: 325 ft.

1700 DC explosions. Close. Boat shaken.

1702 DC explosions. Boat shaken

1703 Escort overhead. Splashes.

1704 DC explosions, close.

1712 DC explosions.

1716 DC explosions.

1731 Pattern of DC explosions.

1739 DC explosions, close.

1803 DC explosion, close.

1809 Close DC. Damage (See Damage Section) Heavy Flooding in forward torpedo. Damage Control Party assigned.

1811 Enemy continued DC runs.


1812 Forward torpedo room reports flooding reported under control, but three feet of water in compartment. Repairs continued

1818 Flooding controlled. Leaks completely stopped. Boat is heavy forward, difficult to control depth. Pumping water out.

1845 Forward torpedo reports water pumped out of compartment.

1848 Battery power down to thirty percent.

1900 Escorts pinging.

1097 DC explosion.

1912 DC explosion, close.

2100-2201 Multiple DC attacks by escort. Seal pushed to depth of 390 ft.

2202 Lost contact with enemy vessels, believe they were "sleeping".

2225 Sound reported an enemy vessels moving away, fast.

2317 Periscope depth. All clear. Sound is clear.

2318 Surfaced. Recharged batteries. Secure General Quarters. Battery power was down to fifteen percent.

2350 Maintain course 120 to Lamon Bay at 10 knots. Upon completion of battery recharge, increased speed to 15.5 knots.


Friday December 25 1941

0750 Submerged.


1802 Periscope depth. Dusk. Received Evening Fox Traffic. Hong Kong captured by Japanese, Manila declared open city. Asiatic Fleet operations shift to Surabaya, Java.

1822 Surfaced.

2340 Night Orders: Continued on course 200 at 18.5 knots en route to arrive off Lamon Bay by dawn.



Friday December 26, 1941


0630 Approaching Lamon Bay from the North.

0951 Submerged for reconnoiter of Lamon Bay area.

1149 Sound reports distant fast props bearing 155.

1315 Patrolling destroyer spotted bearing 211 5 NM. Rigged for Silent Running.

1742 two destroyers spotted 120 6000 yards. Identified as Kagero Class and Mutsuki Class. This pair was patrolling Lamon Bay. It is believed the enemy landing force is inside Lopez Bay, which can be reached from Lamon Bay but is too shallow to enter submerged, Both entrances are relatively narrow and guarded by shore defense guns, as well as patrol craft.

1842 Nightfall. Surfaced in Lamon Bay.

2200-2240 Pursued by a patrol craft but able to elude after a prolonged chase.

2256 Exited Lamon Bay.

2340 Night Orders: Continue course for patrol of approaches to Lamon Bay, P.I.


Saturday December 27, 1941


Patrolled East of Lamon Bay

Night Orders: Continue course and speed to arrive off North entrance to Laganoy Gulf, P. I. by dawn to interdict traffic to/from Lamon Bay.



Sunday December 28, 1941

0500 Wind and seas picked up, 6-8 ft waves.

0530 Submerged for patrol. of North entrance of Laganoy Gulf.

0832 Sound reports prop noises bearing 340 long range.

0852 Spotted group of landing craft. General Quarters-Battle Surface Gun Action.

0902 Surfaced.

0903 Commenced firing on lead barge. Barge opened fire with machine guns or auto cannon, no hits on Seal. One solid round on fifth shot hit the landing craft, which caught fire and crew abandoned.

0930 Ceased fire. six Daihatsu Class Landing Craft estimated 9 tons each at 14-03 N 123-53 E.

0935 Secured General Quarters.

1232 Aircraft spotted! Bearing 248 6 NM DIVE! Emergency, 200 ft. 14-38 N 123-65 E


1830 Surfaced. Recharge Batteries.



2340 Night Orders: Maintain course and speed for arrival off San Bernadino Strait by dawn.




Monday December 29, 1941

0317 Sighted enemy destroyer bearing 5000 yards. Avoided this patrol.

0525 Submerged for patrol off Laganoy Gulf.

1110 Patrolling destroyer spotted bearing 292 5 NM.

1835 Surfaced. Recharge Batteries.

2340 Night Orders: Patrol San Bernadino Strait/Laganoy/Albay Gulf areas.



Tuesday December 30, 1941

0248 Convoy Sighted. 12-54 N 124-11 E in San Bernadino Strait. Estimated Course/Speed 003 degrees 9 knots. One large AP, two DD,

0450 Lost contact with convoy in the dark, appears it turned into Albay Gulf.


0530 Submerged for patrol.

1303 Aircraft Spotted! Bearing 229. 200 ft, emergency.


1830 Surfaced. Recharged Batteries. Heavy seas with Partial clouds, light fog , and heavy wind.

2340 Night Orders Continue course 120 speed 15kts 30-50 NM off coast of Samar.



Wednesday December 31, 1941

0348 Ship spotted 358 degrees 8000 yards. Shadowing until dawn for attack.

0415 Vessel Identified as md sized tanker.


0540 General Quarters-Torpedo

0614 Submerged for Attack.


0642 Target identified as tanker AKEBONO MARU 6839 tons.

0653 Fired three MK 14 torpedoes.

0654 Torpedoes one and two hit target, third missed astern. Massive explosion and fireball, believe tanker was loaded with fuel as was southbound.

0656 AKEBONO MARU 6839 tons sunk 12-07 N 126-18 E 58 NM ENE off Samar, P.I.

0708 Depth 200 feet. Secured General Quarters. Commenced torpedo reload with final reserve torpedo. Two torpedoes left in tubes left, tubes 3 and 4.

1836 Surfaced. Recharged Batteries.

2340 Night Orders: Maintain course 155 degrees at 15.5 knots.



Monday January 1, 1942

1505 Aircraft spotted! (IJN twin engine bombers) Bearing 153 9500 yards closing fast! DIVE ! Emergency, 200 feet. 7-18 N 127-15 E 40 NM E of Mindanao.

1506 Bombs hit water about 100 feet from Seal as she passed 52 feet.

1830 Surfaced. Recharged batteries.

2340 Night Orders: Maintain Course192 degrees 15.5 knots.




Tuesday January 2, 1942


0600 Transiting Celebes "chokepoint" south of Mindanao into Celebes Sea en route new base at Surabaya, Java.

0930 Entered Celebes Sea.


1802 Evening Fox reported Manila captured today.


Night Orders: Maintain course 240 at 15.5 knots en route Surabaya.



Wednesday January 3, 1942

1134 Sighted Dutch flagged freighter 2500 tons. Position 01-47 N 120-9 E Course 020 7 knots.


1807 Overcast, Heavy winds, rain, waves and fog set in. Waves 8-10 feet.



2340 Night orders: Maintain course200 speed 15.5 knots.


Thursday January 4, 1942

1900 Storms cleared. Light chop, partial clouds, light fog.


2340 Night orders: Maintain course 220 speed 15.5 knots.



Friday January 5, 1942

Night Orders: Maintain pattern off Java coast until dawn, then set course to enter port.


Saturday January 6, 1942

1000 Docked Surabaya, Java. Terminated patrol.



(C) Torpedo Attacks

Seal conducted a total of six torpedo attacks, firing twenty of twenty two MK 14 torpedoes aboard., sinking three ships, damaging another.

One gun action utilizing the 3" 50 caliber aft deck gun and 20 MM Oerlikon Cannon sunk five barges, one of which was armed and returned fire.


Ships Sunk by Torpedo Attack

1.

Name: MOMOYAMA MARU
Class:AK
Tonnage: 4,037
Date:20 December 1941
Time:2038
Location:19-17 N 118-48 E. in Luzon Straits.
Type of Attack and Sinking/Damage determined by:
Night Periscope-Submerged Attack. Visual observation through periscope of torpedo impact and sinking of vessel.

Data (at firing)

Range:1000 yards
AOB:85 Port
Gyro:350 Left
Track:355 Port
Course:350
Tubes Fired:1,2,3,4
Torp.Depth:10 feet
POA:MOT, MOT, Fore, Aft
POI:MOT
Detonator: Magnetic actuated by contact.
Hit/Miss: Torpedoes 1,2,3 hit, four missed.
Result: Target sunk.


2.

Name: SEIA MARU
Class:AK
Tonnage: 7,590
Date:24 December 1941
Time:1121
Location:19-58 N 121-33 E. in Bashi Channel
Type of Attack and Sinking/Damage determined by:
Day Periscope Submerged Attack. Visual observation of torpedo impacts and sinking of vessel.


Torpedo Data (at firing)
Range:800 yards
AOB:110 Starboard
Gyro:01
Track:02
Course:004
Tubes Fired:1,2,3.
Torp.Depth:10 feet
POA:MOT
POI:MOT
Detonator: Magnetic actuated by contact.
Hit/Miss: Torpedoes 1,2,3 hit.
Result: Target sunk.




3.

Name: AKEBONO MARU
Class:AO
Tonnage: 6,839
Date:31 December 1941
Time: 0656
Location: 12-07 N 126-18 E 58 NM ENE off Samar, P.I.
Type of Attack and Sinking/Damage determined by:
Dawn Periscope Submerged Attack. Visual observation of torpedo impacts and sinking of vessel.


Torpedo Data (at firing)
Range:1000 yards
AOB:88 Port
Gyro:02 L
Track:12
Course:014
Tubes Fired:1,2,3
Torp.Depth:20 feet
POA:MOT, Fore, Aft Stack
POI:MOT, Fore
Detonator: Magnetic actuated by contact.
Hit/Miss: Torpedoes 1,2, hit, 3 missed astern.
Result: Target sunk.


Ships Damaged by Torpedo Attack

1.

Name: AKITA MARU
Class:AK
Tonnage: 3.900
Date:20 December 1941
Time: 1515
Location: 19-15 N 116-48 E in Luzon Straits
Type of Attack and Damage determined by:
Day Submerged Periscope Attack. Observed torpedo impacts and vessel listing to starboard but underway.


Torpedo Data (at firing)

Range:1100 yards
AOB:87 Port
Gyro:01 Left
Track:08
Course:351
Tubes Fired:1,2,
Torp.Depth:10 feet
POA:MOT, MOT
POI:MOT
Detonator: Magnetic actuated by contact.
Hit/Miss: Torpedo #1 detonated prematurely, torpedo #2 impacted target.
Result: Target Damaged.


Remarks on torpedo attacks:

Magnetic influence detonators may need adjusting as several detonated too early. For targets such as Destroyers torpedo depth should be set as shallow as possible to utilize contact exploder as several misses occurred in spite of solid firing solutions.




(D) Gunnery

Seal departed with 150 rounds of 3" 50 Caliber and 1,200 rounds of 20 MM ammunition aboard

One gun attack was made during this patrol.

Date:28 December 1941
Time:0903-0930
Location: 14-03 N 123-53 E off North Entrance to Laganoy Gulf, P.I.

Description of attack:

While patrolling just North of Laganoy Gulf submerged on the morning of 28 December, made sound contact. Upon coming to periscope depth, observed a small convoy of motorized landing craft/barges heading 340 degrees in a single, loose column, likely or a coastal run to Lamon Bay. Seas were choppy but suitable for gunnery.

Closed to 2000 yards submerged and brought the stern about. Observed the lead Daihatsu was armed with what appeared to be machine guns or auto-cannon (20-25 MM) forward and thus designated it as first target. At 0902 blew tanks for a quick "pop" up to the surface, and commenced firing at 0903.

The first round impacted just besides the craft, but as a near miss appeared to damage it. Second round was a direct hit, caused a large explosion, likely detonating the ammunition aboard. A few survivors were seen in the water.

The remaining craft attempted to flew but were overtaken and two more disposed of quickly by the 3 inch gun. The fourth and fifth landing craft were disposed of by the 20 MM cannon, which proved quite effective against these targets.

At 0930 all were sunk, sinking, and ablaze, ceased firing.


Rounds expended:

3 inch:23


20 MM:211


Result:

Sunk six Daihatsu Class Landing Craft Estimated 9 tons each.



(E) Weather


Weather conditions were favorable for majority of the patrol. Most nights were dark with a slight moon. In the waters off the east coast of the Philippine Islands heavy seas and winds were encountered.



(F) Radio

Radio function was excellent, in spite of the antenna being damaged in depth charge attack.



(G) Major Defects and Damage

During the depth charge attack on 24 December 1941, Seal suffered serious damaged from a very close depth charge explosion forward at 1809, while at a depth of 325 feet.
The damage caused flooding forward, which made the boat heavy forward, difficult to control depth and hindering required quiet for the evasion. Loss of control due to heavy, and quick flooding caused the boat at one point reach a depth of 402 feet before control was regained with back emergency power, dive plane manipulation, and slight release of water from tanks.

While leaks were stopped within minutes, the flooding was heavy and took several hours to pump the compartment dry and restore normal control of the boat. This process was not quiet and aided the attackers in continuing to drop close depth charges. While were not at aware until arrived in boat of the hull damage forward, we worked to make sure did not dive deeper than we had due to possible hull weakness caused by the close charge.

The damage control party lead by the Executive Officer and Engineering officer performed in in spectacularr fashion, saving the boat.

Damage suffered in this attack and repair status:

1.Serious hull damage forward (24 percent)-repaired in port.

2.Bulkhead, forward hatch damage.-repaired at sea

3.Serious flooding forward torpedo room-3 1/2 feet water in compartment-pumped out.

4.Torpedo tubes 3, and rendered inoperable-repaired at sea.

5. Forward batteries damaged-repaired at sea.

6. Various water piping and air lines damaged, leaking-repaired.



During the depth charge attack of 21 December, a close charge, perhaps two exploded near the boat and conning tower. Busted valves permitted several inches of water to enter the conning tower, but were quickly stopped by men in the compartment. Later, when at periscope depth, it was discovered both periscopes had been seriously damaged. Inspection upon surfacing found the heads of both No.1 and No.2 were damaged. A damage control team immediately began to repair and had both scopes operational within six hours.

Damage suffered in this attack and repair status:

1. No. 1 Periscope head-repaired at sea.

2. No. 2 Periscope head-repaired at sea.

3. Torpedo Data Computer-repaired at sea.

4. Valves, piping, air lines.-repaired at sea.

5.Flooding in conning tower-pumped out compartment.

6. 20 MM Cannon-repaired at sea.

7. Radio Antenna-repaired at sea.



(H) Anti-Submarine Measures and Evasion Tactics


Enemy anti-submarine efforts were intense in the Luzon Strait areas and effective. Seal was bombed multiple times by four engine flying boat patrol aircraft as well as twin engine land based bombers.

ASW patrols consisting of destroyers were encountered numerous times throughout the area.

The attack by one such patrol on 24 December, responding to the sinking of SEIA MARU, proved to be quite competent and effective.

Enemy utilized team work with passive and active sound gear, preferring to make an approach from the stern and drop patterns "along the spine4" of the submarine. When in pairs, one would make a fast run this way, then another would quickly follow and "cross the T" in front of Seal, laying effective patterns.


Submerged evasion of enemy ASW consisted of running silent at 100 RPM or less, always with five degrees or rudder to port or starboard, in order to prevent Seal from being tracked in one direction, this seemed to confusion. When enemy was heard overhead making a run, speed speed bursts of 6-8 knots were used typically for 30-60 seconds. Seal initially operated at test depth of 250 ft for evasion but several times was forced to 270 0r 275 to get under enemy depth charges. Later depths of 350 ft were found necessary and due to flooding, the boat went to 402 feet momentarily.

300-350 feet seems to be an excellent depth to evade enemy depth charges and sound gear.


(I) Mines

No enemy mines were encountered.


(K) Friendly Forces Contacted

1.

USN Tambor Class Submarine
14 December 1941
0705
14-15 N 120-26 E.
Bearing 083
Range 9000 yards.
Course 100 degrees.
Speed 15 kts
Location: 14-15 N 120-26 E. Outside entrance to Manila Bay.
Exchange Rec Signal: No
Remark: Spotted while departing for patrol.



2.

USN Tambor Class Submarine
16 December 1941
0543
19-5 N 120-47 E
Bearing 083
Range 9000 yards.
Course 265 degrees.
Speed: 12 knots
Location:19-5 N 120-47 E in Luzon Straits, West of Babuyan Islands.
Exchange Rec Signal: No
Remark: Believed was enemy submarine. Tracked, submerged, and approached for dawn periscope attack. On observation at 1200 yards, recognized in the morning light as a USN submarine. Immediately broke off attack and went to 200 ft.





3.

Dutch Flagged Freighter 2500 tons
3 January 1942
1134
19-5 N 120-47 E
Bearing 040
Range 5.5 NM
Course 020 degrees.
Speed: 7 knots
Location:01-47 N 120-9 E n Celebes Sea
Exchange Rec Signal: Yes
Remark: None




(L) Aircraft

Enemy aircraft contacts consisted of large four engine flying patrol boats and twin engine land based bombers, no single engine fighters or bombers were encountered.

Multiple aircraft bombed Seal during the patrol but caused no damaged. (See Narrative)


(M) Health, Habitability, and Crew.

Health and Habitability on this patrol were excellent.The crew conducted themselves in an excellent manner during an active, and trying first war patrol.

Total on Board: 62 Officers and men.

Officers:5
Chief Petty Officers:6
Petty Officers:21
Men:30
Qualified in Submarines: 40


Injuries:

Following crew suffered minor injuries in the forward torpedo room during the depth charge attack of 24 December 1941. All were treated at sea and returned to full duty.

TM1 Bell, H.
TM1 Simmons, L.
TM3 Howard, G.T.
TM3 Jenkins, D.T.
S1 Campbell, T.N.
S2 Lynch, G.
SC1 Anderson, V.R.






(N) Navgiational Aids

Due to blackouts, no nagivational aids were sighted in patrol area or the adjoining islands.



(O) Sound Gear and Conditions

Sound gear, both passive and active functioned properly during this patrol, with optimal conditions for most of the patrol with faint contacts often heard nearly ten miles away.

Enemy appeared to enjoy the same conditions as well.

Thermal layers were present in area and detected between 100 and 300 feet.



(P) Miles Steamed-Fuel Used

Miles Gallons
Cavite to Patrol Area 400 3240
In Patrol Area 6500 31209
Patrol Area to Surabaya 2856 21449



(Q) Duration

Days
Manila to Patrol Area 2
In patrol area 17
Area to Surabaya 5
Days Submerged 18
Total 26

Factor in Termination of Patrol: Fuel, distance to new base from area, battle damage, expenditure of torpedoes.

(R) Patrol Routine

A standard patrol routine was established on this patrol consisting with three sections standing four hours watches as follows:

0400-800
0800-1200
1200-1600
1600-2000
2000-0000



When surfaced, the Officer of the Deck (OOD) stood watch on the bridge, along with port, starboard, and aft look outs. In the control room the Chief of the Watch supervised the men assigned to control room watch at diving controls. When dive alarm is sound, Chief of the Watch initiates the dive with the control room watch until the port and starboard lookouts are able to make their way from the bridge to the control room, where they take over the dive planes, and OOD takes over the dive. Sound station in conning tower is manned by the assigned Sonarman of the watch upon the dive alarm being sounded. The Chief of the Watch then mans the "Christmas Tree" once the OOD has taken over the dive. Once a dive is complete and proper trim made, the OOD will take station in the conning tower and may issue diving commands from there, unless otherwise required. The exception to this is the the second section, in which the Executive Officer is assigned as OOD, a second officer, as assistant Officer of the Deck (AOOD) stands watch in conning tower and drops down to take over the dive upon sounding of the dive alarm.

Transit to and from assigned patrol areas was conducted on the surface at standard speed, submerging as required.

Daily routine in patrol area consisted of a dive to 90 feet, shortly after dawn. Submerged patrolling typically consisted of a climb periscope depth everyone half hour at 50-54 feet with No.2 periscope in conning tower extended, although in some areas observations were longer. Constant passive sound sweeps were conducted, which produced contacts and ultimately sinkings. Surfaced patrolling in area became untenable due to enemy aircraft presence.

Surfacing just after dusk, typically between 1830-1845 hours was the routine for this patrol. Battery recharge was conducted then a increase to standard speed to cover a box search pattern through the night was conducted. This wielded several excellent contacts.


Procedure upon contact with unknown surface vessel was to turn away presenting stern , until situation can be assessed. Contacts with enemy patrols were avoided via this procedure. Exception for this procedure if the tell tale smoke plume of a large merchant spotted, then a matching course and speed were ordered, with initiation of plot.

Upon spotting of an aircraft, procedure for OOD was to order a dive to to 200 feet. If no bombs fell, it appeared the boat was not spotted, a return to periscope depth and surfacing within the hour was procedure.

During torpedo attacks, the Commanding Officer, assisted by the Executive Officer conducted the approach and manning of the periscopes. The Dive Officer manned the dive, with Torpedo Officer on the Torpedo Data Computer. Engineering Officer was in the control room in constant contact with the engine rooms. The Chief of the Boat was in the conning tower during a torpedo attack, assigned to the torpedo fire control panel.

This routine proved effective and useful for this patrol. If two more officers could be added, each watch would have an OOD and AOOD, enhancing the capabilities of the boat and crew.


(S) Remarks

The assigned area of Luzon Straits was the sight of initial patrol. Numerous warnings of invasion at Lamon Bay and Eastern P.I. were received. A status report to COMSUB Asitatic prompted orders to reconnoiter Lamon Bay and San Bernadino Strait areas.

The enemy effectively controls the Luzon Straits with surface and air patrols, aside from US submarines.

While did sink three vessels and damage another, torpedo performance did leave something to be desired with four premature detonations (possibly more) and several suspected of running deeper than set. These issues should be address immediately.


Installation of an SD Air Search Radar is a top priority prior to next patrol as well.