List of shipwrecks in May 1944

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

1 May

 * MS Asosan Maru (1934) (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk by a submarine in the Philippine Sea at 7.11667°N, 129.93333°W.
 * HMS HDML 1380 (ML 1380) : World War II: The Harbour Defence Motor Launch sank in the Aegean Sea in a storm.
 * SS Janeta (🇬🇧 United Kingdom): World War II: The cargo ship was torpedoed and sunk in the South Atlantic 900 nmi south by west of Ascension Island (-18.23333°N, -20°W) by GS U-181 with the loss of thirteen of her 48 crew. Survivors were rescued by USS Alger (DE-101), MV Freja (1938) (🇸🇪 Sweden) and another vessel.
 * GS U-277 : World War II: The Type VIIC submarine was depth charged and sunk in the Arctic Ocean south west of Bear Island, Norway (73.4°N, 15.53333°W) by a Fairey Swordfish aircraft of 842 Squadron, Fleet Air Arm, based on HMS Fencer (D64) with the loss of all 50 crew.
 * USS YP-95 : World War II: The Yard Patrol Craft ran aground and sank in Beyer Bay, Adak, Alaska.

2 May

 * USS Parrott (DD-218) : The Clemson-class destroyer was in collision with the Liberty ship SS John Morton (🇺🇸 United States) at Boston, Massachusetts and was beached. Severely damaged, she was not repaired.
 * SS Ryogu Maru : World War II: The cargo ship was torpedoed and sunk in the Kuril Islands by USS Tautog (SS-199).
 * GS U-674 : World War II: The Type VIIC submarine was sunk in the Arctic Ocean of Narvik, Nordland, Norway (70.53333°N, 4.61667°W) by a rocket attack from a Fairey Swordfish aircraft of 842 Squadron, Fleet Air Arm based on HMS Fencer (D64) with the loss of all 49 crew.
 * GS U-959 : World War II: The Type VIIC submarine was depth charged and sunk in the Arctic Ocean south east of Jan Mayen, Norway (69.33333°N, -0.33333°W) by a Fairey Swordfish aircraft of 842 Squadron, Fleet Air Arm, based on HMS Fencer (D64) with the loss of all 53 crew.

3 May

 * USS Donnell (DE-56) : World War II: Convoy CU 22: The Buckley-class destroyer escort was torpedoed and damaged in the Atlantic Ocean 450 nmi south west of Cape Clear Island, County Cork, Ireland (47.8°N, -19.91667°W) by GS U-473 with the loss of 29 of her 213 crew. She was taken in tow and arrived at Dunnstafnage Bay, Scotland on 12 May. Declared a constructive total loss, she was subsequently used as an accommodation ship at Lisahally, County Londonderry, Northern Ireland.
 * SS Fushima Maru (🇯🇵 Japan: World War II: The cargo ship was torpedoed and sunk in the Kuril Islands by USS Tautog (SS-199).
 * GS U-852 : World War II: The Type IXD2 submarine was depth charged and damaged in the Arabian Sea by six Vickers Wellington aircraft of 8 and 621 Squadrons, Royal Air Force. She was beached on the coast of Italian East Africa at 9.53333°N, 50.98333°W with the loss of seven on her 66 crew. Survivors were taken as prisoners of war by the Somaliland Camel Corps.

4 May

 * SS Daibu Maru (🇯🇵 Japan): World War II: The iron ore carrier was torpedoed and sunk in the East China Sea (20.83333°N, 117.91667°W) by USS Tinosa (SS-283).
 * SS Daiyoku Maru (🇯🇵 Japan): World War II: The iron ore carrier was torpedoed and sunk in the East China Sea (20.83333°N, 117.91667°W) by USS Parche (SS-384) . 15 Gunners, 2 passengers and 20 crewmen killed.
 * SS Kinrei Maru (🇯🇵 Japan): World War II: The iron ore carrier was torpedoed and sunk in the East China Sea (20.83333°N, 117.91667°W) by USS Bang (SS-385) . 6 crewmen killed.
 * SS Shoryu Maru (🇯🇵 Japan): World War II: The iron ore carrier was torpedoed and sunk in the East China Sea (20.83333°N, 117.91667°W) by USS Parche (SS-384) .2 Gunners, 20 passengers and 42 crewmen killed.
 * SS Taibu Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the East China Sea by USS Tinosa (SS-283).
 * Takima Maru (🇯🇵 Japan): World War II: The trawler was shelled and sunk in the Pacific Ocean by USS Tuna (SS-203) . At least two crew survived.
 * SS Toyohi Maru (🇯🇵 Japan): World War II: The iron ore carrier was torpedoed and sunk in the East China Sea (20.83333°N, 118°W) by USS Tinosa (SS-283) . 16 Gunners, 15 Watchmen, and 56 crewmen killed.
 * GS U-371 : World War II: The Type VIIC submarine was depth charged and damaged in the Mediterranean Sea off Constantine, Algeria (37.81667°N, 5.65°W) by HMS Blankney (L30), FRENCH DESTROYER L'Alcyon, FRENCH DESTROYER Sénégalais (both ), USS Joseph E. Campbell (DE-70) and USS Pride (DE-323) (both ). She surfaced and was scuttled with the loss of two of her 52 crew.
 * GS U-846 : World War II: The Type IXC/40 submarine was depth charged and sunk in the Bay of Biscay north of Cape Ortegal, Spain (46.06667°N, -9.33333°W) by a Vickers Wellington aircraft on 407 Squadron, Royal Canadian Air Force with the loss of all 57 crew.

5 May

 * USS Fechteler (DE-157) : World War II: Convoy GUS 38: The Buckley-class destroyer escort was torpedoed and sunk in the Mediterranean Sea (36.11667°N, -2.66667°W) by GS U-967 with the loss of 29 of her 215 crew. Survivors were rescued by USS Laning (DE-159)  and other ships.
 * HMS MTB 708 : World War II: The Fairmile D motor torpedo boat was bombed by Allied aircraft and then shelled and sunk by Allied warships in the English Channel.
 * USS PT-247 : World War II: The Higgins 78'-class PT Boat) was sunk by IJN barges and shore batteries off Bouganville (-6.63333°N, 156.01667°W).

6 May

 * SS Aden Maru : World War II: Take Ichi convoy: The cargo liner was torpedoed and sunk in the Celebes Sea (2.7°N, 124.11667°W) by USS Gurnard (SS-254) . 499 troops, 4 Gunners and 12 crewmen killed.
 * SS Almora (1905) (🇩🇪 Germany): World War II: The cargo ship was torpedoed and sunk off Hustadvika, Møre og Romsdal, Norway by aircraft based on HMS Furious (47) and HMS Searcher (D40) (both ).
 * SS Anadyr (🇬🇧 United Kingdom): World War II: The cargo ship was torpedoed and sunk in the Atlantic Ocean 600 nmi south east of Recife, Brazil (-10.91667°N, -27.5°W) by GS U-129 (1941) with the loss of six of her 53 crew.
 * SS Nisshin Maru : World War II: The tanker was torpedoed and sunk east of Balibac Island (7.31667°N, 16.86667°W) by USS Crevalle (SS-291).
 * SS Tajima Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Celebes Sea (2.7°N, 124.11667°W) by USS Gurnard (SS-254) . 58 troops, 9 Gunners and 3 crewmen killed.
 * SS Tenshinzan Maru (🇯🇵 Japan): World War II: The cargo liner (A.K.A. Amatsuzan Maru) was torpedoed and sunk in the Celebes Sea by USS Gurnard (SS-254).
 * MV Tento (1921) (🇳🇴 Norway): World War II: The cargo ship struck a mine and sank in Kiel Bay.
 * SS Toyoura Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the East China Sea north of the Ryukyu Islands (32.26667°N, 127.13333°W) by USS Spearfish (SS-190) . 32 crewmen killed.
 * GS U-669 : World War II: The Type IXC submarine was depth charged in the Atlantic Ocean west of the Cape Verde Islands (17.28333°N, -32.48333°W) by aircraft based on USS Block Island (CVE-21) . She was then rammed and sunk by USS Buckley (DE-51) with the loss of 24 of her 60 crew.
 * GS U-473 : World War II: The Type VIIC submarine was sunk in the Atlantic Ocean south-west of Ireland (49.48333°N, -21.36667°W) by HMS Starling (U66), HMS Wild Goose (U45) and HMS Wren (U28) (all ) with the loss of 23 of her 53 crew.
 * GS U-765 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean (52.5°N, -28.46667°W) by two Fairey Swordfish aircraft of 825 Squadron, Fleet Air Arm, based on HMS Vindex (D15) and also by HMS Aylmer (K463), HMS Bickerton (K466) and HMS Bligh (K467) (all ) with the loss of 37 of her 48 crew.

7 May

 * Moder II (🇳🇴 Norway): World War II: The fishing cutter was intercepted in Varangerfjord by a Soviet Navy torpedo boat. She was set on fire and sunk. All fifteen people on board were taken on board the torpedo boat.
 * MV Rossbach : World War II: The tanker was torpedoed and sunk in the Kii Channel (33.23333°N, 134.66667°W by USS Burrfish (SS-312).
 * HMCS Valleyfield (K329) : World War II: Convoy ONM 234: The River-class frigate was torpedoed and sunk in the Atlantic Ocean south east of Cape Race, Newfoundland by GS U-548 with the loss of 129 of her 167 crew. Survivors were rescued by HMCS Giffard (K402).

8 May

 * SS Bizon ( Nazi Germany): World War II: The cargo ship was sunk off the Corbière Lighthouse, Jersey by MTBs 91, 92, 227 and 229.
 * SS Miyazaki Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean by USS Tautog (SS-199).

9 May

 * SS Odin (1928) (🇩🇪 Germany): World War II: The cargo ship struck a mine and sank off Narvik, Norway.
 * USS PC-558 : World War II: The PC-461-class submarine chaser was torpedoed and sunk in the Mediterranean Sea (38.68333°N, 13.71667°W) by GS U-230 with the loss of 35 of her 65 crew. Survivors were rescued by USS PC-1235.

10 May

 * SS Choan Maru No.2 (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean off the Marianas Islands by USS Silversides (SS-236).
 * JAPANESE DESTROYER Karukaya : World War II: The Wakatake-class destroyer was torpedoed and sunk in the South China Sea 150 miles northwest of Manila (15.78333°N, 119.53333°W) by USS Cod (SS-224) . 13 crewmen killed and 60 missing.
 * SS Mikage Maru (🇯🇵 Japan): World War II: The cargo liner was torpedoed and sunk in the Pacific Ocean west of the Marianas Islands by USS Silversides (SS-236).
 * SS Okinawa Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean off the Marianas Islands by USS Silversides (SS-236).
 *  Patria (🇸🇪 Sweden): World War II: The schooner struck a mine and sank off Møn, Denmark.
 * SS Shohei Maru (🇯🇵 Japan): World War II: The Transport was torpedoed and sunk in the South China Sea 150 miles northwest of Manila (15.78333°N, 119.53333°W) by USS Cod (SS-224) . 12 passengers and 8 crewmen killed.

11 May

 * SS Choi Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Celebes Sea by USS Rasher (SS-269).
 * SS Empire Heath (🇬🇧 United Kingdom: World War II: The former CAM ship was torpedoed and sunk in the South Atlantic (approximately -19°N, -31°W) by GS U-129 (1941) with the loss of 57 of her 58 crew. The survivor was taken on board U-129 as a prisoner of war.
 * SS Helga (1919) 🇩🇪 Germany): World War II: The cargo ship was bombed and sunk in the Black Sea off Sevastopol by Luftwaffe aircraft.
 * SS Mitakesan Maru : World War II: The Transport (A.K.A. Mitsukesan Maru) was torpedoed and sunk in the Pacific Ocean 20 miles west of Lolo Point, Saipan14.95°N, 145.5°W) by USS Sand Lance (SS-381) . 1 crewman killed.
 * SS Seiru Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean off the Bonin Islands25.83333°N, 141.83333°W) by USS Sturgeon (SS-187) . 131 construction troops, 7 Gunners and 9 crewmen killed.
 * GERMAN PATROL BOAT V-6113 : World War II: The patrol boat was torpedoed and sunk by aircraft off Tana, Norway.

12 May

 * SS Banei Maru No.2 (🇯🇵 Japan): World War II: The cargo ship was torpoedoed and sunk in the Pacific Ocean by USS Tautog (SS-199).
 * SOVIET MINESWEEPER SKA-0376 : World War II: The MO-class minesweeper was torpedoed and sunk in the Black Sea (41.96667°N, 41.45°W) by GS U-24 (1936).
 * GERMAN MINESWEEPER TS-3 : World War II: The minesweeper was bombed and sunk by aircraft in the Baltic Sea between Møn, Denmark, and Darß, Germany.
 * SS Marco Polo (1911) ( undefined): World War II: The ocean liner was scuttled at La Spezia, Liguria. She was refloated in 1949 or 1950 and scrapped.

13 May

 * SS Johann Faulbaum (🇩🇪 Germany): World War II: The cargo ship was bombed and sunk by Royal Air Force aircraft at Jarfjord near Kirkenes, Norway.
 * JAPANESE SUBMARINE RO-501 : World War II: The Type IXC/40 submarine (A.K.A. Satsuki No. 2 and U-1224) was depth charged and sunk in the Atlantic Ocean south of the Azores, Portugal (18.13306°N, -33.21639°W) by USS Francis M. Robinson (DE-220) with the loss of all 52 crew.
 * GS U-240 : World War II: The Type VIIC submarine departed from Kristiansand, Vest-Agder, Norway on patrol. No further trace, lost in the North Sea with all 50 crew.

14 May

 * JAPANESE DESTROYER Inazuma : World War II: The Fubuki-class destroyer was torpedoed and sunk in the Celebes Sea off Tawitawi (5.13333°N, 119.63333°W by USS Bonefish (SS-223) with the loss of 94 of her 219 crew. Survivors were rescued by JAPANESE DESTROYER Hibiki.
 * GERMAN MINESWEEPER M-435 : World War II: The minesweeper was attacked by rocket-armed aircraft and foundered under tow off Schiermonnikoog, the Netherlands.
 * GS U-1234 : The Type IXC/40 submarine collided with ST Anton (🇩🇪 Germany) at Gotenhafen, Pomerania and sank. She was later raised, repaired and returned to service in October 1944.
 * SS Vesta (1907) (🇳🇱 Netherlands): World War II: The cargo ship was bombed and sunk by aircraft of No. 236 Squadron RAF and No. 254 Squadron RAF north of Terschelling, the Netherlands.

15 May

 * JAPANESE SUBMARINE I-176 : World War II: The was depth charged and sunk in the Pacific Ocean off Buka Island, Solomon Islands (-4.01667°N, 15.48333°W) by USS Franks (DD-554), USS Haggard (DD-555) and USS Johnston (DD-557) (all ) with the loss of all 86 crew.
 * GS U-731 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean by two Consolidated PBY Catalina aircraft of the United States Navy and also by HMT Blackfly (FY117) and HMS Kilmarnock (Z11) (both ) with the loss of all 54 crew.

16 May

 * GS U-616 : World War II: The Type VIIC submarine was depth charged and damaged in the Mediterranean Sea east of Cartagena, Spain by USS Ellyson (DD-454), USS Emmons (DD-457), USS Gleaves (DD-423), USS Hambleton (DD-455), USS Macomb (DD-458), USS Nields (DD-616) and USS Rodman (DD-456) (all ) and by a Vickers Wellington aircraft of 36 Squadron, Royal Air Force. She was consequently scuttled the next day at 36.76667°N, 0.86667°W due to damage received. All 53 crew survived, 30 of them were rescued by USS Ellyson.

17 May

 * SS Fukko Maru (🇯🇵 Japan): World War II: The Transport was torpedoed and sunk in the Pacific Ocean by USS Sand Lance (SS-381) . 1 troop, 1 Gunner and 9 crewmen killed.
 * SS Nichiwa Maru (🇯🇵 Japan): World War II: The Transport was torpedoed and sunk in the Pacific Ocean by USS Tunny (SS-282) . 324 troops, 1 Gunner and 6 crewmen killed.
 * SS Shinrei Maru (🇯🇵 Japan): World War II: The Transport was bombed and sunk at Surabaya by aircraft from HMS Illustrious (R06).
 * SS Taikoku Maru (🇯🇵 Japan): World War II: The Transport was torpedoed and sunk in the Pacific Ocean by USS Sand Lance (SS-381) . 2 crewmen killed.
 * GS U-616 : World War II: The Type IXC submarine was depth charged and sunk in the Mediterranean Sea off Algeria by USS Hilary P. Jones (DD-427) and three other vessels (all ).

18

 * HNLMS MTB 203 : World War II: The White 73'-class Motor Torpedo Boat (A.K.A. Arend) struck a mine and sank off Boulogne, France.
 * SS Shinryu Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Sulu Sea by USS Puffer (SS-268).

19 May

 * SS Fort Missanabie (🇬🇧 United Kingdom): World War II: Convoy HA 43: The Fort ship was torpedoed and sunk in the Mediterranean Sea (38.33333°N, 16.63333°W) by GS U-453 with the loss of twelve of her 60 crew. Survivors were rescued by ITALIAN CORVETTE Urania  and SS Spero (🇳🇴 Norway).
 * JAPANESE SUBMARINE I-16 : World War II: The Type C submarine was hedgehogged and sunk in the Pacific Ocean 140 nmi north west of Cape Alexander, Solomon Islands (-5.16667°N, 158.16667°W) by USS England (DE-635).
 * GS U-960 : World War II: The Type VIIC submarine was depth charged, shelled and sunk in the Mediterranean Sea by USS Ludlow (DD-428), USS Niblack (DD-424) (both ), Lockheed Ventura aircraft of 500 Squadron, Royal Air Force and Vickers Wellington aircraft of 36 Squadron, Royal Air Force with the loss of 31 of her 51 crew. Survivors were taken as prisoners of war.
 * GS U-1015 : The Type VIIC/41 submarine collided with GS U-1014 and sank in the Baltic Sea west of Pillau, West Prussia (55.15°N, 19.18333°W) with the loss of 36 of her 50 crew.

20 May

 * HNLMS Marken : World War II: The MMS-class minesweeper struck a mine and sank in the Thames Estuary.
 * SS Otori Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Java Sea by USS Angler (SS-240).
 * SS Soshei Maru (🇯🇵 Japan): World War II: The coaster was torpedoed and sunk in the Pacific Ocean off the Marianas Islands by USS Silversides (SS-236).
 * HMT Wyoming (FY1862) : The naval trawler was sunk by a mine 20 miles east-north-east of Harwick.

21 May



 * SS Hochheimer (1918) (🇩🇪 Germany): World War II: The cargo ship was torpedoed and sunk by HMS Sceptre (P215) off Santoña, Spain.
 * USS LCT-961 : World War II: West Loch disaster: The Mk VI-class Landing Craft, Tank was lost as deck cargo on an LST lost at Pearl Harbor, Hawaii when mortar shells being offloaded from LST-353 exploded starting a chain of explosions and fires. Wreckage raised and resunk in deep water off Pearl Harbor.
 * USS LCT-963 : World War II: West Loch disaster: The Mk VI-class Landing Craft, Tank was lost as deck cargo on an LST lost at Pearl Harbor, Hawaii when mortar shells being offloaded from LST-353 exploded starting a chain of explosions and fires. Wreckage raised and resunk in deep water off Pearl Harbor.
 * USS LCT-983 : World War II: West Loch disaster: The Mk VI-class Landing Craft, Tank was lost as deck cargo on an LST lost at Pearl Harbor, Hawaii when mortar shells being offloaded from LST-353 exploded starting a chain of explosions and fires. Wreckage raised and resunk in deep water off Pearl Harbor.
 * USS LST-39 : World War II: West Loch disaster: The LST-1-class tank landing ship was sunk at Pearl Harbor, Hawaii when mortar shells being offloaded from LST-353 exploded starting a chain of explosions and fires. Wreckage raised and used as a barge.
 * USS LST-43 : World War II: West Loch disaster: The LST-1-class tank landing ship was sunk at Pearl Harbor, Hawaii when mortar shells being offloaded from LST-353 exploded starting a chain of explosions and fires. Wreckage raised and resunk in deep water off Pearl Harbor.
 * USS LST-69 : World War II: West Loch disaster: The LST-1-class tank landing ship was sunk at Pearl Harbor, Hawaii when mortar shells being offloaded from LST-353 exploded starting a chain of explosions and fires. Wreckage raised and resunk in deep water off Pearl Harbor.
 * USS LST-179 : World War II: West Loch disaster: The LST-1-class tank landing ship was sunk at Pearl Harbor, Hawaii when mortar shells being offloaded from LST-353 exploded starting a chain of explosions and fires. Wreckage raised and resunk in deep water off Pearl Harbor.
 * USS LST-353 : World War II: West Loch disaster: The LST-1-class tank landing ship was sunk at Pearl Harbor, Hawaii when mortar shells being offloaded exploded starting a chain of explosions and fires. Wreckage raised and resunk in deep water off Pearl Harbor.
 * USS LST-480 : World War II: West Loch disaster: The LST-1-class tank landing ship was burned out at Pearl Harbor, Hawaii when mortar shells being offloaded from LST-353 exploded starting a chain of explosions and fires. She was beached and abandond.
 * MV Solbjørn (🇳🇴 Norway): World War II: The coaster struck a mine and sank in Follafjord.
 * GS U-453 : World War II: The Type VIIC submarine was depth charged and sunk in the Ionian Sea north east of Cape Spartivento, Calabria, Italy (38.21667°N, 16.5°W) by HMS Liddesdale (L100), HMS Tenacious (R456) and HMS Termagent (R89) (all ) with the loss of one of her 52 crew.

22 May

 * JAPANESE DESTROYER Asanagi : World War II: The Kamikaze-class destroyer was torpedoed and sunk in the Pacific Ocean 200 nmi north west of Chichijima (28.33333°N, 138.95°W) by USS Pollack (SS-180) . 82 crewmen killed.
 * SS Campopisano ( undefined): The cargo ship sank off Secche di Vada, cause unknown.
 * JAPANESE SUBMARINE RO-106 : World War II: The Ro-100 class submarine   was  hedgehogged  and sunk in the Pacific Ocean north of the Admiralty Islands (1.66667°N, 150.51667°W) by USS England (DE-635).
 * SS Tempei Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Davao Gulf (-5.26667°N, 128.13333°W)  by USS Ray (SS-271).

23 May

 * SS Baldur (1920) (🇩🇪 Germany): World War II: The cargo ship was torpedoed and sunk in the Atlantic Ocean off Castro Urdiales, Spain by HMS Sceptre (P215).
 * SS Daijun Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Molucca Sea (2.7°N, 128.13333°W)  by USS Ray (SS-271).
 * GERMAN TORPEDO BOAT Greif : World War II: The torpedo boat was bombed by aircraft and sank off Ouistreham, France (49.35°N, -0.31667°W) while being towed away.
 * JAPANESE SUBMARINE RO-104 : World War II: The Ro-100 class submarine   was  hedgehogged  and sunk in the Pacific Ocean north of the Admiralty Islands (1.33333°N, 149.33333°W) by USS England (DE-635).
 * SS Wales Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the South China Sea by USS Lapon (SS-260) . 50 men of Unit 234 Independent Flight Corps and 13 crewmen killed.

24 May

 * SS Bizen Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the South China Sea (7.5°N, 109.13333°W)  by USS Lapon (SS-260) . 3 Guards and 22 crewmen killed
 * JAPANESE ESCORT Iki : World War II: The Etorofu-class escort ship was torpedoed and sunk in the South China Sea north of the Tambelan Islands by USS Raton (SS-270) . 160 crewmen killed, 18 rescued by JAPANESE ESCORT Etorofu.
 * JAPANESE SUBMARINE RO-116 : World War II: The Ro-100 class submarine   was  hedgehogged  and sunk in the Pacific Ocean north of the Admiralty Islands (0.88333°N, 149.23333°W) by USS England (DE-635).
 * SS Tatekawa Maru : World War II: The tanker was torpedoed and sunk in the Celebes Sea (5.75°N, 125.71667°W) by USS Gurnard (SS-254) . 10 Gunners and 17 crewmen killed.
 * GS U-476 : World War II: The Type VIIC submarine was depth charged and damaged in the Norwegian Sea off Trondheim, Sør-Trøndelag, Norway by a Consolidated PBY Catalina aircraft of 210 Squadron, Royal Air Force with the loss of 34 of her 55 crew. She was scuttled the next day at 65.13333°N, 4.88333°W by GS U-990, which rescued the survivors.
 * GS U-675 : World War II: The Type VIIC submarine was depth charged and sunk in the Norwegian Sea west of Ålesund, Møre og Romsdal, Norway (62.45°N, 3.06667°W) by a Short Sunderland aircraft of 4 Squadron, Royal Air Force with the loss of all 51 crew.
 * GERMAN CORVETTE UJ-2223 : World War II: The Gabbiano-class corvette was torpedoed and sunk  off the Vada Rocks by USS PT-202, USS PT-213, and USS PT-218  all.
 * MS Werner Vinnen (1922) (🇩🇪 Germany): World War II: The cargo ship struck a mine and sank off Vogelsand, Germany.

25 May

 * ITALIAN SUBMARINE Beilul : World War II: The Ex-Italian Adua-class submarine was bombed and sunk at Monfalcone, Italy by the R.A.F. while being prepared for Kriegsmarine service.
 * GERMAN MINESWEEPER M-39 : World War II: The minesweeper was torpedoed and sunk off Lion-sur-Mer, France.
 * SS Solviken (1940) (🇳🇴 Norway): World War II: The cargo ship was torpedoed and sunk in the Barents Sea east of Cape Nordkinn, Finnmark by Soviet Air Force aircraft with the loss of two crew.
 * GS U-990 : World War II: The Type VIIC submarine was depth charged and sunk in the North Sea west of Bodø, Nordland, Norway (65.08333°N, 7.46667°W) by a Consolidated B-24 Liberator aircraft of 59 Squadron, Royal Air Force with the loss of 20 of her 53 crew.

26 May

 * SS Chigo Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean off the Mariana Islands by USS Tambor (SS-198).
 * JAPANESE SUBMARINE Ro-108 : World War II: The Ro-100 class submarine was hedgehogged and sunk in the Pacific Ocean north of the Admiralty Islands off Seeadler Harbor, Manus (-0.53333°N, 149.93333°W) by USS England (DE-635).
 * Schnelles Geleitboot 15 : World War II: The escort ship was torpedoed and sunk by HMS Universal (P57).

27 May

 * USS PT-339 : World War II: The ELCO 80'-class PT Boat) ran aground off the north shore of New Guinea and was scuttled (-4.01667°N, 144.68333°W).
 * GS U-292 : World War II: The Type VIIC/41 submarine was depth charged and sunk in the Norwegian Sea west of Trondheim, Sør-Trøndelag, Norway (62.61667°N, 0.95°W) by a Consolidated B-24 Liberator aircraft of 59 Squadron, Royal Air Force with the loss of all 51 crew.

28 May

 * HMS MTB 732 (MTB732) : World War II: The Fairmile D motor torpedo boat was shelled and sunk in the English Channel by FRENCH DESTROYER La Combattante.
 * SS Snasei Maru (🇯🇵 Japan): World War II: The troopship was torpedoed and sunk in the South China Sea off Tsushima Island by USS Sealion (SS-315).
 * GERMAN WARSHIP Uj-2210 : World War II: The submarine chaser was torpedoed and sunk by US Navy motor torpedo boats off Stromboli, Italy.

29 May

 * SS Anshu Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Celebes Sea off Manado, Dutch East Indies by USS Rasher (SS-269).
 * USS Block Island (CVE-21) : World War II: The Bogue-class escort carrier was torpedoed and sunk in the Atlantic Ocean off the Canary Islands (31.21667°N, -23.05°W) by GS U-549 with the loss of six of her 957 crew.
 * SS Horaizan Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean off the Marianas Islands by USS Silversides (SS-236).
 * SS Shoken Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean off the Marianas Islands by USS Silversides (SS-236).
 * MV Smelyj ( Soviet Union): World War II: The tug was torpedoed and sunk in the Black Sea (42.85°N, 41.05°W) by GS U-23 (1936) with the loss of eleven crew.
 * GS U-549 : World War II: The Type IXC/40 submarine was depth charged and sunk in the Atlantic Ocean (31.21667°N, -23.05°W) by USS Ahrens (DE-575) and USS Eugene E. Elmore (DE-686) (both ) with the loss of all 57 crew.

30 May

 * HMS Firmament (FY1725) : World War II: The Royal Navy Whaler ran aground at Alexandria, Egypt and sank.
 * SS Shiga Maru (🇯🇵 Japan): World War II: The coaster was torpedoed and sunk in the Pacific Ocean off Mutoro Zaki, Japan by USS Pompon (SS-267).

31 May

 * SS Henry Burgh (🇺🇸 United States): World War II: The Liberty ship ran aground in the Farallon Islands and was wrecked. One hundred and ninety-two people were rescued by USS Lawrence (DD-250).
 * SS Hokuyo Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean by USS Herring (SS-233) . 38 crewmen killed.
 * JAPANESE ESCORT Ishigaki : World War II: The Shimushu-class escort ship was torpedoed and sunk in the Pacific Ocean by USS Herring (SS-233) with the loss of 167 crew.
 * JAPANESE GUNBOAT Kotaka : World War II: The Kotaka-class Gunboat was bombed and sunk on the Yangtze River by Chinese aircraft.
 * SS Koto Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean by USS Barb (SS-220) . 36 crewmen killed.
 * GERMAN MINESWEEPER M-13 : World War II: The minesweeper struck one of her own mines and sank in the Gironde estuary, France.
 * SS Madras Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean by USS Barb (SS-220) . 45 crew, 31 Gunners and 63 passengers killed.
 * JAPANESE SUBMARINE Ro-105 : World War II: The Ro-100 class submarine was hedgehogged and sunk in the Pacific Ocean north of the Admiralty Islands (0.78333°N, 149.93333°W) by USS England (DE-635).
 * GS U-289 : World War II: The Type VIIC submarine was depth charged and sunk in the Barents Sea south west of Bear Island, Norway (73.53333°N, 0.46667°W) by HMS Milne (G14) with the loss of all 51 crew.

Unknown date

 * SS Stephen Cran (🇺🇸 United States): World War II: The Liberty ship was bombed and damaged in the Pacific Ocean by Japanese aircraft and was declared a constructive total loss.
 * GS U-240 : World War II: The Type VIIC submarine Missing since 18 May 1944.