List of shipwrecks in April 1944

The list of shipwrecks in April 1944 includes ships sunk, foundered, grounded, or otherwise lost during April 1944.

1 April

 * SS Dahomian (1929) (🇬🇧 United Kingdom): World War II: The United Africa Company 5,277 grt cargo ship was torpedoed and sunk in the South Atlantic 10 nmi west south west of Cape Point, South Africa (-34.41667°N, 18.31667°W) by GS U-852 with the loss of two of her 51 crew. Survivors were rescued by HMSAS Krugersdorp and HMSAS Natalia (both ).
 * SS Jared Ingersoll (🇺🇸 United States): World War II: Convoy UGS 36: The Liberty ship was torpedoed and damaged in the Mediterranean Sea west of Algiers, Algeria by Luftwaffe aircraft and was abandoned by her crew, who were rescued by USS Mills (DE-383) . USS Mills and the tug HMS Mindfull towed the ship to Algiers.
 * SS Minami Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean (25.98333°N, 131.31667°W) by USS Flying Fish (SS-229).

2 April

 * GS U-360 : World War II: The German Type VIIC submarine was depth charged and sunk in the Norwegian Sea south west of Bear Island, Norway (72.46667°N, 13.06667°W) by HMS Keppel (D84) with the loss of all 51 crew.

3 April

 * SS Fagerstrand I (🇩🇪 Germany): World War II: The factory ship was set on fire and severely damaged in Kåfjord following an Allied attack on GERMAN BATTLESHIP Tirpitz . The wreck was laid up, and scuttled in October 1944 by German forces. Raised in 1947, extended and returned to service in 1950 as Sande.
 * SS Tosei Maru (🇯🇵 Japan): World War II: The cargo liner was torpedoed and sunk in the Pacific Ocean off the Nanpō Islands by USS Pollack (SS-180).
 * GS U-288 : World War II: The Type VIIC submarine was depth charged and sunk in the Barents Sea (73.73333°N, 27.2°W) by Fairey Swordfish aircraft of 819 Squadron, Fleet Air Arm, based on HMS Activity (D94) and Grumman TBM Avenger and Grumman F4F Wildcat aircraft of 846 Squadron, Fleet Air Arm based on HMS Tracker (D24) (both ) with the loss of all 49 crew.

4 April

 * JSUB I-169 : World War II: The was sunk in a diving accident north-west of Dublon Island, Truk, during an air raid by USN PB4Ys.

5 April

 * USS YT-247 : World War II: The harbor tug was swamped and foundered 425 miles south-west of Oahu (14.23333°N, 158.98333°W) while under tow from Pearl Harbor to Palmyra.

6 April

 * SS Ruth I (🇳🇴 Norway): World War II: Convoy SC 156: The cargo ship was torpedoed and sunk in the Atlantic Ocean (45.08333°N, -35.18333°W) by GS U-302 with the loss of three of her 39 crew. Survivors were rescued by HMS Chelmer (K221).
 * MV South America (1931) (🇳🇴 Norway): World War II: Convoy SC 156: The tanker was torpedoed and sunk in the Atlantic Ocean (45.06667°N, -35.36667°W) by GS U-302 . All 42 crew were rescued by SS Goodwin (🇬🇧 United Kingdom).
 * GS U-302 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean (45.08333°N, -35.18333°W) by HMS Swale (K217) with the loss of all 51 crew.
 * SS Wesergau (🇩🇪 Germany): World War II: The cargo ship was torpedoed and sunk off Stad, Norway by HNOMS Ula (1943).

7 April

 * JSUB I-2 : World War II: The Type J1 submarine was depth charged and sunk in the Pacific Ocean off Emirau Island by USS Saufley (DD-465).
 * Rion ( Soviet Union): World War II: The barge struck a mine and sank in the Black Sea (42.18333°N, 41.63333°W).
 * GS U-856 : World War II: The Type IX submarine was depth charged, shelled, rammed and sunk in the Atlantic Ocean (40.3°N, -62.36667°W) by USS Champlin (DD-601) and USS Huse (DE-145) (both ) with the loss of 27 of her 55 crew.

8 April

 * AMMUNITION Aratama Maru : World War II: The Ammunition ship was torpedoed in the Pacific Ocean off  Guam by USS Seahorse (SS-304) . Her cargo of gasoline exploded damaging JAPANESE DESTROYER Asakaze   . She drifted on fire for 3 days before coming to rest on a reef, and sinking in shallow water, in Talafofo Bay, Guam on the 11th.. 4 crewmen killed.
 * SS Honan Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the East China Sea by USS Whale (SS-239).
 * SS Nebraska (🇬🇧 United Kingdom): World War II: The cargo ship was torpedoed and sunk in the South Atlantic (-11.91667°N, -19.86667°W) by GS U-843 with the loss of two of the 68 people on board. Survivors were rescued by SS Kindat (🇬🇧 United Kingdom) or reached land in their lifeboat.
 * GS U-2 (1935) : The Type IIA submarine collided with the trawler Helmi Söhle (🇩🇪 Germany) in the Baltic Sea near Pillau, East Prussia and sank with the loss of seventeen of her 35 crew.
 * GS U-962 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean north west of Cape Finisterre, Spain (45.71667°N, -19.95°W) by HMS Crane (U23) and HMS Cygnet (H83) (both ) with the loss of all 50 crew.

9 April

 * SS Bisaku Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean off the Mariana Islands by USS Seahorse (SS-304).
 * USS SC-497 : World War II: The ) grounded on Cook's Reef, off Mai Island, New Hebrides, and sank the next day.
 * GS U-515 : World War II: The Type IXC submarine was depth charged and damaged in the Atlantic Ocean by USS Chatelain (DE-149), USS Flaherty (DE-135), USS Pillsbury (DE-133) and USS Pope (DE-134) (all ). She surfaced, and was then bombed, shelled and sunk by the four destroyers and by Grumman TBF Avenger and Grumman F4F Wildcat aircraft based on USS Guadalcanal (CVE-60) with the loss of sixteen of her 60 crew.

10 April

 * USS Holder (DE-401) : World War II: The was torpedoed and damaged in the Mediterranean Sea off Algiers, Algeria by Luftwaffe aircraft. She was towed to Oran and then to New York, where she was condemned. A 95 ft section of her stern was used to repair USS Menges (DE-320).
 * GERMAN MINESWEEPER M-459 : World War II: The minesweeper was bombed and sunk by aircraft off Aseri, Estonia (59.5°N, 27.08483°W).
 * MV Oldham (1919) (🇺🇸 United States): World War II: Convoy SC 156: The cargo ship suffered a broken propeller shaft and was abandoned by her 51 crew. They were rescued by SS Goodwin (🇬🇧 United Kingdom). Oldham was towed to St. John's, Newfoundland.
 * GS U-68 (1940) : World War II: The Type IXC submarine was sunk in the Atlantic Ocean (33.4°N, -18.98333°W) by Grumman TBF Avenger and Grumman F4F Wildcat aircraft based on USS Guadalcanal (CVE-60) with the loss of 56 of her 57 crew.

11 April

 * JAPANESE DESTROYER Akigumo : World War II: The was torpedoed and sunk in the Moro Gulf (6.71667°N, 122.38333°W) by USS Redfin (SS-272) . 137 killed including the commanding officer.
 * GERMAN TRAINING SHIP Mars : World War II: The artillery training ship was bombed and wrecked at Stettin, Pomerania in an Allied air raid.
 * SS Stör (1921) (🇩🇪 Germany): World War II: The cargo ship was torpedoed and sunk off Kirkenes, Norway.
 * GS U-108 (1940) : World War II: The Type IXB submarine was bombed and sunk at Stettin, Pomerania in an Allied air raid. She was raised and decommissioned on 17 July. Scuttled 24 April 1945.

12 April

 * USS ATR-98 : The rescue tug was sunk in a collision with tug USS Abnaki (ATF-96) off The Azores(44.06667°N, -24.13333°W).
 * JSUB I-174 : World War II: The was sunk in the Pacific Ocean off Truk, South Pacific Mandate by a Consolidated B-24 Liberator aircraft of the United States Navy.
 * USS PT-135 : World War II: The was scuttled after running aground north of Crater Point, New Britain(-5.35°N, 152.15°W)
 * SS Taichu Maru (🇯🇵 Japan): World War II: The cargo liner was torpedoed and sunk in the Pacific Ocean east of Okinawa, Japan by USS Halibut (SS-232).

13 April

 * JAPANESE DESTROYER Ikazuchi : World War II: The was torpedoed and sunk in the Pacific Ocean by USS Harder (SS-257).
 * Solvoll (🇳🇴 Norway): World War II: The fishing vessel was shelled and sunk in the Norwegian Sea 150 nmi west of the Lofoten Islands by GS U-711 . All eight people on board were taken on board U-711 as prisoners and were held by the Gestapo until the end of the war.

14 April

 * SS Bärenfels (1921) (🇩🇪 Germany): World War II: The cargo ship was sunk by submarine-placed mines off Bergen, Norway.
 * SS Baroda (🇬🇧 United Kingdom): World War II: Bombay Explosion: The  ship was lost as a result of the explosion of Fort Stikine (🇬🇧 United Kingdom) at Bombay, India.
 *  : World War II:  Bombay Explosion:  The Landing Ship, Infantry (Large) was burned out as a result of the explosion of Fort Stikine (🇬🇧 United Kingdom) at Bombay, India.
 * SS Fort Crevier (🇬🇧 United Kingdom): Bombay Explosion: The Fort ship was severely damaged by the explosion of Fort Stikine (🇬🇧 United Kingdom) at Bombay, India. She was subsequently used as a hulk until scrapped in 1948. 1 crewman killed.
 * SS Fort Stikine (1944) (🇬🇧 United Kingdom): Bombay Explosion: The Fort ship exploded and sank at Bombay. The explosion resulted in the loss of twelve other ships.
 * SS Graciosa (🇳🇴 Norway): Bombay Explosion: The cargo ship was severely damaged by the explosion of Fort Stikine (🇬🇧 United Kingdom) and was declared a total loss. She was sold for scrap in July 1944.
 * SS General Van Der Heijden (🇳🇱 Netherlands): World War II: Bombay Explosion: The  ship was lost as a result of the explosion of Fort Stikine (🇬🇧 United Kingdom) at Bombay, India.
 * SS General Van Swiete (🇳🇱 Netherlands): World War II: Bombay Explosion: The  ship was lost as a result of the explosion of Fort Stikine (🇬🇧 United Kingdom) at Bombay, India.
 * SS Iran (1919) (🇵🇦 Panama): Bombay Explosion: The cargo ship was severely damaged by the explosion of Fort Stikine (🇬🇧 United Kingdom) and was declared a total loss.
 * SS Jalapadna ( British India): World War II: Bombay Explosion: The  ship was lifted by the Tidal Wave caused by the explosion of Fort Stikine (🇬🇧 United Kingdom) and broke in two when slammed down on a dock at Bombay, India.
 * SS Kingyuan (🇬🇧 United Kingdom): World War II: Bombay Explosion: The  ship was lost as a result of the explosion of Fort Stikine (🇬🇧 United Kingdom) at Bombay, India.
 * SS Norse Trader (🇳🇴 Norway): World War II: Bombay Explosion: The cargo ship was severely damaged by the explosion of Fort Stikine (🇬🇧 United Kingdom) and was declared a total loss.
 * SS Rod El Farag (🇪🇬 Egypt): World War II:  Bombay Explosion: The  ship was lost as a result of the explosion of Fort Stikine (🇬🇧 United Kingdom) at Bombay, India.
 * SS Tinombo (🇳🇱 Netherlands): World War II: Bombay Explosion: The  ship was lost as a result of the explosion of Fort Stikine (🇬🇧 United Kingdom) at Bombay, India.
 * GS U-448 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean north east of the Azores, Portugal (46.36667°N, -19.58333°W) by HMS Pelican (L86) and HMCS Swansea (K328)  with the loss of nine of her 51 crew.
 * GERMAN CUTTER Vesper : World War II: The fishing cutter was bombed and sunk in the Barents Sea off Makkaur, Finnmark, Norway.

15 April

 * SS Friedrichshafen (1943) (🇩🇪 Germany): World War II: The cargo ship was torpedoed and sunk by HMS Venturer (P68) off Egersund, Norway.
 * JAPANESE MINESWEEPER W-7 : World War II: The was torpedoed and sunk off the Nicobar Islands in the Indian Ocean (11.56667°N, 93.13333°W)   by HMS Storm (P233).

16 April

 * SS Hino Maru No.1 (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Philippine Sea by USS Paddle (SS-263).
 * SS Meyer London (🇺🇸 United States): World War II: Convoy UGS 37: The Liberty ship was torpedoed and sunk in the Mediterranean Sea off Derna, Libya (32.63333°N, 23.13333°W) by GS U-407 All 72 crew were rescued by HMS La Malouine (K46).
 * SS Mito Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Philippine Sea by USS Paddle (SS-263).
 * SS Pan-Pennsylvania (🇺🇸 United States): World War II: Convoy CU 21: The Type T3 tanker was torpedoed and damaged in the Atlantic Ocean 200 nmi east of New York (40.11667°N, -69.4°W) by GS U-550 with the loss of 25 of her 56 crew. Survivors abandoned ship and were rescued by USS Joyce (DE-317) and USS Peterson (DE-152) (both ). Pan Pennsylvania was bombed and sunk on 18 April at 40.4°N, -69.61667°W by Allied aircraft.
 * SS Shinyu Maru (🇯🇵 Japan): World War II: The cargo liner was torpedoed and sunk in the Philippine Sea by USS Redfin (SS-272).
 * SS Thomas G. Masaryk (🇺🇸 United States): World War II: Convoy UGS-37: The Liberty ship was torpedoed and damaged in the Mediterranean Sea 17 nmi off Derna (32.85°N, 23°W) by GS U-407 . All 70 crew abandoned ship and were rescued by HMS La Malouine (K46) . Thomas G. Masaryk was taken in tow by HMS Captive (W148) and beached in Maneola Bay. She was shelled and sunk in order to extinguish the fire that had started when she was torpedoed. She was refloated on 28 August and towed by HMS Captive to Port Said, Egypt but was declared a constructive total loss.
 * GS U-550 : World War II: The IXC/40 submarine was depth charged, shelled, rammed and sunk in the Atlantic Ocean (40.15°N, -69.73333°W) by USS Gandy (DE-764), USS Joyce (DE-317) and USS Peterson (DE-152) (all ) with the loss of 44 of her 56 crew. Survivors were taken as prisoners of war by USS Joyce.
 * SS Yamagata Maru (🇯🇵 Japan): World War II: The cargo liner was torpedoed and sunk in the Philippine Sea by USS Redfin (SS-272).

17 April
For sinking of Imperial Japanese Navy tanker Iro on this date, see 31 March 1944 For sinking of Royal Navy MTB-266 on this date, see 9 March 1944
 * SS James Guthrie (🇺🇸 United States): World War II: The Liberty ship struck a mine and was damaged in the Mediterranean Sea off Salerno, Italy. She was beached at Naples but broke in two and was declared a constructive total loss.
 * SS Matsue Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean by USS Harder (SS-257).
 * GS U-342 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean (60.53333°N, -29.33333°W) by a Consolidated PBY Catalina aircraft of 162 Squadron, Royal Canadian Air Force with the loss of all 51 crew.
 * GS U-986 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean south west of Iceland (50.15°N, -12.85°W) by USS PC-619 and USS Swift (AM-122) (both ) with the loss of all 50 crew.

18 April

 * SOVIET SUBMARINE L-6 : World War II: The Scuka-class submarine was sunk in the Black Sea east of Constanta, Romania (43.46667°N, 31.53333°W) by GERMAN AUXILIARY SUBMARINE CHASER UJ-104.
 * USS Gudgeon (SS-211) : World War II: The was bombed and sunk off Iwo Jima (22.86667°N, 143.53333°W)  by an IJN "Nell" of the 901 Air Group.

19 April

 * Haruno Maru (🇯🇵 Japan): World War II: The Transport was sunk at Sabang, Sumatra Netherlands East Indies by aircraft from HMS Illustrious (R87)   and USS Saratoga (CV-3) (🇺🇸 United States) . 1 crewman killed.
 * SS John Straub (🇺🇸 United States): The Liberty ship broke in two and sank in the Pacific Ocean off Sanak Island, Alaska (54.36667°N, -163.4°W).
 * Kunitsu Maru (🇯🇵 Japan): World War II: The Transport was sunk at Sabang, Sumatra Netherlands East Indies by aircraft from HMS Illustrious (R87)   and USS Saratoga (CV-3) (🇺🇸 United States).
 * GS U-974 : World War II: The U-boat was torpedoed and sunk in the North Sea off Karmsund, Norway (59.13333°N, 5.38333°W) by HNOMS Ula (1943) with the loss of 42 of her 50 crew.

20 April

 * USS Lansdale (DD-426) : World War II: Convoy UGS 38: The was torpedoed and sunk in the Mediterranean Sea off Algiers, Algeria by Junkers Ju 88 aircraft of the Luftwaffe with the loss of 47 of her 279 crew. Survivors were rescued by USS Menges (DE-320) and USS Newell (DE-322) (both ).
 * MV Krosdøl (🇳🇴 Norway): The coaster was sunk off Bergen by the explosion of ST Voorbode.
 * JSUB Ro-45 : World War II: The was torpedoed and sunk in the Pacific Ocean off the Mariana Islands by USS Seahorse (SS-304).
 * SS Paul Hamilton (🇺🇸 United States): World War II: Convoy UGS 38: The Liberty ship was torpedoed and sunk in the Mediterranean Sea off Algiers (37°N, 3.33333°W) by Luftwaffe aircraft.
 * SS Rogaland (1929) (🇳🇴 Norway): The cargo ship was sunk off Bergen by the explosion of ST Voorbode . Raised later that year and laid up at Ølesund. Repaired and returned to service in 1947.
 * Voorbode : The ammunition transport was sunk off Bergen by an accidental explosion.

21 April

 * GERMAN MINELAYER Roland : World War II: The minelayer struck a mine and sank in the Gulf of Finland, west of the Kurgalsky Peninsula (59.72°N, 27.47°W).

22 April

 * MS Bahia (1927) (🇩🇪 Germany): World War II: The cargo ship was torpedoed and sunk off Lista, Norway by HNOMS Ula (1943).
 * SS Jylland (1887) (🇩🇪 Germany): World War II: The coaster struck a mine and sank in the Baltic Sea off the Mecklenburg-Vorpommern coast.
 * GS U-311 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean south west of Iceland (52.15°N, -19.11667°W) by HMCS Matane (K444) and HMCS Swansea (K328) (both ) with the loss of all 51 crew.

23 April

 * JAPANESE DESTROYER Amagiri : World War II: The was sunk in the Makassar Strait 50 miles south of Balikpapan by a mine. 13 crewmen killed. Survivors rescued by JAPANESE CRUISER Aoba and JAPANESE CRUISER Ōi (both ).
 * SS Daiju Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Seto Inland Sea by USS Seadragon (SS-194).

24 April

 * HMS LST 407 (LST407) : World War II: The Mk 2-class LST was run agound off Naples, Italy and not repaired. Returned to US Navy in May 1945.
 * HMS MTB 671 (MTB671) : World War II: The Fairmile D-class Motor Torpedo Boat was shelled and sunk off Cape Barfluer, France by  Destroyers.
 * HMS Roode Zee (W162) : World War II: The Rescue Tug was torpedoed  and sunk off Dungeness, England by  Schnellboot S-100.

25 April

 * GERMAN TORPEDO BOAT TA-23 : World War II: The, was damaged by a mine off Capri. Scuttled by TA-29 when attacked by Royal Navy M.T.B.s.
 * GS U-488 : World War II: The Type XIV submarine was depth charged and sunk in the Atlantic Ocean (17.9°N, -38.08333°W) by USS Barber (DE-161), USS Frost (DE-144), USS Huse (DE-145) and USS Snowden (DE-246) (all ) with the loss of all 64 crew.

26 April

 * MV Colin (🇵🇦 Panama): World War II: Convoy SC 157: The cargo ship straggled behind the convoy due to steering gear defects. She was torpedoed and sunk in the Atlantic Ocean (54.26667°N, -31.96667°W) by GS U-859 with the loss of one of her 55 crew. Survivors were rescued by HMS Affleck (K462) and HMS Bentley (K465) (both ).
 * SS Eugenio C. (1928) (🇩🇪 Germany): World War II: The cargo ship was bombed and sunk by aircraft south of Bodø, Norway.
 * JSUB I-180 : World War II: The was depth charged, hedgehogged and sunk in the Pacific Ocean south west of Chirikof Island (55.16583°N, -155.66667°W) by USS Gilmore (DE-18)  with the loss of all 86 crew.
 * SS Itauri (1922) (🇩🇪 Germany): World War II: The cargo ship was bombed and sunk by aircraft south of Bodø, Norway.
 * SS Lotte Leonhardt (1937) (🇩🇪 Germany): World War II: The cargo ship was bombed and sunk by aircraft off Fuglo, south of Bodø, Norway.
 * SS Miike Maru (🇯🇵 Japan): World War II: The cargo liner was torpedoed and sunk in the Pacific Ocean off Palau by USS Trigger (SS-237).
 * GERMAN TORPEDO BOAT T-29 : World War II: The torpedo boat was sunk with gunfire and torpedoes off Jentilez, France.
 * GS U-488 : World War II: The Type XIV submarine was depth charged and sunk in the Atlantic Ocean west of the Cape Verde Islands, Portugal (17.9°N, -38.08333°W) by USS Barber (DE-161), USS Frost (DE-144), USS Huse (DE-145) and USS Snowden (DE-246) (all ) with the loss of all 64 crew.
 * SS Wazan Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Kii Channel by USS Sargo (SS-188).
 * SS Yoshida Maru No.1 (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the South China Sea by USS Jack (SS-259) with the loss of all 2,649 people on board.

27 April

 * SS Akigawa Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean off the Mariana Islands by USS Seahorse (SS-304).
 * SS Axel (1878) (🇩🇪 Germany): World War II: The cargo ship was bombed and sunk by aircraft at the Deutsche Werke yard in Kiel, Germany.
 * Daisun (🇯🇵 Japan): World War II: The trawler was shelled and sunk in the South China Sea by USS Jack (SS-259).
 * USS Etamin (AK-93) : World War II: The was torpedoed and damaged in Milne Bay Japanese aircraft. She consequently became a storage hulk.
 * SS Genbu Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean by USS Halibut (SS-232).
 * JAPANESE MINELAYER Kanome : World War II: The minelayer was torpedoed and sunk in the Pacific Ocean by USS Halibut (SS-232).
 * GS U-803 : World War II: The Type IXC/40 submarine struck a mine and sank in the Baltic Sea off Swinemünde, Pomerania with the loss of nine of her 44 crew. Salvaged in August 1944 and cannibalized for parts.
 * JAPANESE CRUISER Yūbari (🇯🇵 Japan): World War II: The cruiser was torpedoed and sunk in the Pacific Ocean off Palau (5.33333°N, 132.26667°W) by USS Bluegill (SS-242).

28 April

 * USS LST-507 : World War II: The Landing Ship, Tank was torpedoed and sunk in Lyme Bay England off Slapton Sands (50.46667°N, -2.85°W) by E-Boats.
 * USS LST-531 : World War II: The Landing Ship, Tank was torpedoed and sunk in Lyme Bay England off Slapton Sands (50.46667°N, -2.85°W) by E-Boats.

29 April
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 * HMCS Athabaskan (G07) : World War II: The destroyer was torpedoed and sunk in the English Channel off Saint-Brieuc, Côtes-du-Nord, France by GERMAN TORPEDO BOAT T-24  with the loss of 124 of her 219 crew.
 * JSUB I-183 : World War II: The was torpedoed and sunk in the Pacific Ocean 30 miles south of Cape Ashizuri, Japan (32.11667°N, 133.05°W) by USS Pogy (SS-266).
 * USS PT-346 : World War II: The ) was sunk by US Navy aircraft in the Bismarck Sea off Cape Lambert, New Britian Island (-4.21667°N, 151.45°W) . 9 killed and 9 of 11 survivors wounded.
 * USS PT-347 : World War II: The ) was sunk by US Navy aircraft in the Bismarck Sea off Cape Lambert, New Britian Island (-4.21667°N, 151.45°W) . 2 killed and 3 of 13 survivors wounded.
 * GERMAN TORPEDO BOAT T-27 : World War II: The torpedo boat was sunk with gunfire at Brignogan-Plages, France.
 * Tahure (🇫🇷 Vichy French Navy): World War II: The Arras-class aviso Colonial Sloop was torpedoed and sunk in the South China Sea off the Hon Doi Islands, Cape Varella, French Indochina (13.03333°N, 109.46667°W) by USS Flasher (SS-249).
 * SS Takegawa Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean (19.33333°N, 118.83333°W).  by USS Bang (SS-385) . 7 crewmen killed.
 * GS U-421 : World War II: The Type VIIC submarine was bombed and sunk at Toulon, Var France during an American air raid.

30 April

 * SS Nittatsu Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean (19.36667°N, 118.75°W).  by USS Bang (SS-385) . 7 crewmen killed.
 * SS William S. Thayer (🇺🇸 United States): World War II: Convoy RA 59: The Liberty ship was torpedoed and sunk in the Barents Sea off Bear Island, Norway by GS U-307 with the loss of 43 of the 234 people on board. Survivors were rescued by SS Robert Eden (🇺🇸 United States and HMS Whitehall (D94), which scuttled the still-floating stern section of the ship.

Unknown date

 * USS Gudgeon (SS-211) : The departed from Johnston Island on patrol, no further trace. Possibly sunk on 18 April either south east of Iwo Jima or off the Maug Islands with the loss of all 60 crew.
 * GS U-193 : The Type IXC/40 submarine was sunk in the Bay of Biscay on or after 23 April with the loss of all 59 crew. Cause unknown.
 * GS U-355 : The Type VIIC submarine disappeared in the Barents Sea between 1 and 4 April with the loss of all 52 crew. Cause unknown.
 * GS U-455 : The Type VIIC submarine disappeared in the Ligurian Sea on or after 6 April with the loss of all 51 crew. Cause unknown.