List of shipwrecks in April 1943

The list of shipwrecks in April 1943 includes ships sunk, foundered, grounded, or otherwise lost during April 1943.

1 April

 * Lubiana : World War II: The Beograd-class destroyer was either sunk by Royal Air Force aircraft off Tunisia, or ran aground off Cap Bon, Tunisia.
 * USS YP-235 :World War II: The Yard Patrol Craft was sunk by an explosion in the Gulf of Mexico.

2 April

 * SS City of Baroda (🇬🇧 United Kingdom): World War II: Convoy NC 9: The passenger ship was torpedoed and damaged in the Atlantic Ocean 90 nmi south west of Luderitz Bay, South-West Africa (-27.93333°N, 15.35°W) by GS U-509 with the loss of eight of the 338 people on board. Survivors abandoned ship and were rescued by HMT Cape Warwick (FY167) . City of Baroda came ashore two days later and broke up on 26 April. She was declared a total loss.
 * SS Dundrum Castle (🇬🇧 United Kingdom): The cargo ship caught fire and sank in the Red Sea, (14.61667°N, 42.38333°W).
 * SS Gogra (🇬🇧 United Kingdom): World War II: Convoy OS 45: The cargo ship was torpedoed and sunk in the Atlantic Ocean 230 nmi west of Oporto, Portugal by GS U-124 (1940) with the loss of 82 of her 90 crew. Survivors were rescued by SS Danby (🇬🇧 United Kingdom) and SS New Northland (🇨🇦 Canada).
 * SS Katha (🇬🇧 United Kingdom): World War II: Convoy OS 45: The cargo ship was torpedoed and sunk in the Atlantic Ocean 320 nmi west of Oporto by GS U-124 (1940) with the loss of six of her 64 crew. Survivors were rescued by SS Danby (🇬🇧 United Kingdom) and HMS La Malouine (K46).
 * SS Lysefjord (🇳🇴 Norway): World War II: The cargo ship was torpedoed and sunk in the Atlantic Ocean (23.15°N, -83.4°W) by GS U-155 (1941) with the loss of four of her 23 crew. Survivors were rescued by SS Howard (1895) (🇺🇸 United States).
 * HMS MTB 63 (MTB63) : World War II: The Vosper 70'-class motor torpedo boat was sunk in a collision off Benghazi, Libya, with HMS MTB 64 (MTB64).
 * HMS MTB 64 (MTB64) : World War II: The Vosper 70'-class motor torpedo boat   was sunk in a collision off Benghazi, Libya, with HMS MTB 63 (MTB63).
 * HMS MTB 267 (MTB267) : World War II: The ELCO 70' -class Motor Torpedo Boat was damaged by a storm in the Mediterranean Sea while sailing from Benghazi to Malta and was scuttled.
 * MV Melbourne Star (1936) (🇬🇧 United Kingdom): World War II: The cargo liner was torpedoed and sunk in the Atlantic Ocean (28.08333°N, -57.5°W) by GS U-129 (1941) with the loss of 115 of the 119 people on board. Survivors were rescued by a Consolidated PBY Catalina aircraft of the United States Navy.
 * Simon Duhamel II (🇫🇷 France): World War II: Convoy TE 20: The trawler straggled behind the convoy due to engine trouble. She was torpedoed and sunk in the Mediterranean Sea (36.01667°N, -2.48333°W) by GS U-755 with the loss of 53 of her 54 crew.
 * SS Toyo Maru No.2 (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean off the Caroline Islands (7.36667°N, 149.3°W)  by USS Tunny (SS-282) . 51 passengers and crew killed, 1 survivor.
 * U-124 : World War II: The Type IXB submarine was shelled and sunk in the Atlantic Ocean west of Oporto, Portugal by Black Swan and Stonecrop (both with the loss of all 53 crew.

3 April

 * JAPANESE TANKER Arima Maru : World War II: The Fleet Tanker was torpedoed and damaged north of  Palau (10.2°N, 134.58333°W)by USS Haddock (SS-231)  . Sank the next day.
 * SS Gulfstate (🇺🇸 United States): World War II: The oil tanker was torpedoed and sunk in the Atlantic Ocean 50 nmi south east of Marathon Key, Florida by GS U-155 (1941)  with the loss of 43 of her 61 crew. Survivors discovered by a U.S. Navy blimp were rescued by a United States Coast Guard aircraft with the assistance of USS Noa (DD-343) . 70 years later in 2013, she again became a target, this time of the National Oceanic and Atmospheric Administration's Remediation of Underwater Legacy Environmental Threats (RULET) project, which hunts down potential sources of oil pollution from sunken vessels.
 * JAPANESE SUBMARINE CHASER CH-13 : World War II: The submarine chaser was torpedoed and sunk with all hands in the Pacific Ocean east of Honshu (41.05°N, 141.96667°W)  by USS Pickerel (SS-177).
 * JAPANESE TRANSPORT Florida Maru : World War II: The Transport was bombed and sunk at Kavieng, New Ireland (-2.58333°N, 150.81667°W)  by 5th Air Force B-17s
 * JAPANESE CARGO SHIP Tosei Maru : World War II: The Fleet Supply ship was torpedoed and sunk 5 miles south of  Tori Shima (30.23333°N, 139.75°W) by USS Pollock (SS-180)  . 1 passenger killed

4 April
For the foundering of the British cargo ship Nagara on this day, see the entry for 29 March 1943.
 * MS Altair (1941) : World War II: The supply ship was torpedoed and sunk by aircraft off Norway.
 * SS Koa Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean off the Jaluit Atoll, Marshall Islands (13.18333°N, 161.95°W) by USS Porpoise (SS-172).
 * SS Patria (1901) (🇩🇪 Germany): World War II: The cargo ship was bombed and sunk by aircraft off Stavanger, Norway.
 * SS Rygja (1920) (🇳🇴 Norway): World War II: The cargo ship struck a mine and sank in the North Sea off Skagen, Denmark with the loss of one crew member.

5 April

 * SS Aloe (🇬🇧 United Kingdom): World War II: The cargo ship was torpedoed and sunk in the Indian Ocean 420 nmi south east of Durban, South Africa (-32.61667°N, 37.83333°W) by GS U-182 . All 47 crew survived. The captain was taken on board U-182 as a prisoner of war. The rest of the crew were rescued by SS Alexander Ramsey (🇺🇸 United States).
 * SS Blitar (🇳🇱 Netherlands): World War II: Convoy HX 231: The cargo ship romped ahead of the convoy. She was shelled and damaged in the Atlantic Ocean by GS U-229 . The next day, she was torpedoed and sunk (57.75°N, -27.5°W) by GS U-632 with the loss of 26 of her 62 crew.
 * SS British Ardour (🇬🇧 United Kingdom): World War II: Convoy HX 231: The tanker was torpedoed and damaged in the Atlantic Ocean west of Ireland (58.13333°N, -34.06667°W) by GS U-706 . All 62 crew were rescued by HMS Snowflake (K211) and HMS Vidette (D48) (both ), the former of which scuttled the ship.
 * JAPANESE SUBMARINE Ro-34 : World War II: The Kaichū VI (Ro-33 class) submarine was depth charged and sunk in the Pacific Ocean off the Russell Islands (-8.25°N, 158.96667°W) by USS O'Bannon (DD-450) and USS Strong (DD-467) with the loss of all 66 crew.
 * MV Shillong (🇬🇧 United Kingdom): World War II: Convoy HX 231: The cargo ship was torpedoed and damaged in the Atlantic Ocean south east of Cape Farewell, Greenland by GS U-635 . She was the torpedoed and sunk (57.16667°N, -35.5°W) by GS U-629 with the loss of 71 of her 78 crew. Survivors were rescued by SS Zamalek (🇬🇧 United Kingdom).
 * MV Sunoil (🇺🇸 United States): World War II: convoy HX 231: The tanker straggled behind the convoy. She was torpedoed and damaged in the Atlantic Ocean by GS U-563 (. She was later torpedoed and sunk at 58.26667°N, -34.23333°W by GS U-530 with the loss of all 69 crew.
 * GS U-167 (1942) : World War II: The Type IXC/40 submarine was depth charged and damaged in the Atlantic Ocean off the Canary Islands, Spain (approximately 27.78333°N, -15°W by a Lockheed Hudson aircraft of 233 Squadron, Royal Air Force. She was scuttled the next day. All 52 crew survived.
 * GS U-635 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean south east of Iceland (58.33333°N, -31.86667°W) by a Consolidated B-24 Liberator aircraft onf 120 Squadron, Royal Air Force with the loss of all 47 crew.
 * MV Vaalaren (🇸🇪 Sweden): World War II: Convoy HX 231: The cargo ship romped ahead of the convoy. She was torpedoed and sunk in the Atlantic Ocean (approximately 58°N, -34°W) by GS U-229 ( with the loss of all 38 crew.
 * SS Waroonga (🇬🇧 United Kingdom): World War II: Convoy HX 231: The cargo ship was torpedoed and damaged in the Atlantic Ocean by GS U-635 . She was then torpedoed and damaged further by GS U-630 with the loss of nineteen of the 132 people on board. Survivors were rescued by SS Joel R. Poinsett (🇺🇸 United States) and HMS Loosestrife (K105), which scuttled the ship.

6 April

 * SS John Sevier (🇺🇸 United States): World War II: Convoy GTMO 83: The Liberty ship was torpedoed and sunk in the Caribbean Sea 20 nmi off Great Inagua Island, Cuba (20.28333°N, -73.53333°W) by GS U-185 (. All 57 crew were rescued by USS Bennett (DD-473).
 * SS San Diego (1930) (🇫🇷 France) World War II: The cargo ship was bombed and sunk by aircraft near Bizerte, Tunisia.
 * SS Ste. Lucille (🇩🇪 Germany): World War II: The cargo ship was bombed and sunk at Trapani, Sicily, Italy by Allied aircraft.
 * GS U-376 : World War II: The Type VIIC submarine departed from La Pallice, Charente-Maritime, France on patrol. No further trace, presumed lost in the Bay of Biscay with the loss of all 47 crew.
 * GS U-632 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean (58.03333°N, -28.7°W) by a Consolidated B-24 Liberator aircraft of 86 Squadron, Royal Air Force with the loss of all 48 crew.

7 April

 * USS Aaron Ward (DD-483) : World War II: The Gleaves-class destroyer was bombed and sunk in Ironbottom Sound by Japanese aircraft with the loss of 27 of her 208 crew.
 * SS Fukuei Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean by USS Pickerel (SS-177).
 * USS Kanawha (AO-1) : World War II: The Kanawha-class oiler was bombed and damaged in Tulagi Harbor by Japanese aircraft and beached. She sank the next day with a loss of 19 crew.
 * MS Kosei Maru (1940) (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean (8.75°N, 147.16667°W) by USS Tunny (SS-282).
 * HMNZS Moa (T233) : World War II: The Bird-class minesweeper was bombed and sunk in Tulagi Harbour, Solomon Islands by Japanese aircraft with the loss of five of her 35 crew.
 * GS U-644 : World War II: The Type VIIC submarine was torpedoed and sunk in the Norwegian Sea west of Narvik, Nordland, Norway (69.63333°N, -5.66667°W) by HMS Tuna (N94) with the loss of all 45 crew.

8 April

 * MV Castillo Montealegre (🇪🇸 Spain): World War II: The cargo ship was torpedoed and sunk in the Atlantic Ocean off French Sudan (9.76667°N, -16.83333°W) by GS U-123 (1940) with the loss of twelve of her 43 crew. Survivors were rescued by HMS Inkpen (T225).

9 April

 * MV Bamako (🇫🇷 France): World War II: The cargo ship was torpedoed and sunk in the Atlantic Ocean off Dakar, Senegal (14.95°N, -17.25°W) by GS U-515 with the loss of six crew.
 * JAPANESE DESTROYER Isonami : World War II. The Fubuki-class destroyer was torpedoed and sunk in the Banda Sea 35 nmi south east of Wangi-wangi Island, Indonesia (-5.43333°N, 123.06667°W) by USS Tautog (SS-199) with the loss of seven of her 219 crew.
 * JAPANESE CARGO SHIP Oyama Maru (🇯🇵 Japan): World War II: The cargo ship (A.K.A. Yuzan Maru) was torpedoed and sunk 250 miles north-north-west of Kaveing, New Ireland Island (0.63333°N, 150.28333°W), by USS Drum (SS-228) . 4 crewmen killed
 * SS Penang Maru (🇯🇵 Japan: World War II: The cargo ship was torpedoed and sunk in the Banda Sea by USS Tautog (SS-199).
 * SS Shanghai Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Isla Verde Passage by USS Grayling (SS-209).
 * GS U-733 : The Type VIIC submarine collided with another U-boat and sank at Gotenhafen, West Prussia. She was raised, repaired and returned to service.

10 April

 * SS Alice F. Palmer (🇺🇸 United States): World War II: The Liberty ship was torpedoed, shelled and sunk in the Indian Ocean (-26.5°N, 44.33333°W) by GS U-177.
 * MV Irene (1938) (🇩🇪 Germany): World War II: The blockade runner was shelled and sunk in the Atlantic Ocean (43.3°N, -14.43333°W) by HMS Adventure (M23).
 * ITALIAN CRUISER Trieste : World War II: The Trento-class cruiser was bombed and sunk at La Maddelena, Sardinia by United States Army Air Forces aircraft. She was raised post-war and sold to Spain in 1951 for a proposed conversion to an aircraft carrier. This was not proceeded with and she was subsequently scrapped.

11 April

 * HMS Beverley (H64) : World War II: Convoy ON 176: The Clemson-class destroyer was torpedoed and sunk in the Atlantic Ocean (52.31667°N, -40.46667°W by GS U-188 with the loss of 148 of her 152 crew.
 * SS Edward B. Dudley (🇺🇸 United States): World War II: Convoy HX 232: The Liberty ship straggled behind the convoy. She was torpedoed and sunk in the Atlantic Ocean (approximately 53°N, -38°W / 53°N, -39°W) by GS U-615 with the loss of all 69 crew.
 * SS Empire Whimbrel (🇬🇧 United Kingdom): World War II: The cargo ship was torpedoed and sunk in the Atlantic Ocean 400 nmi south south west of Freetown, Sierra Leone (2.51667°N, -15.91667°W) by GS U-181 . All 53 crew were rescued by HMS Witch (D89) and HMS Wolverine (D78) (both ).
 * SS Frode (1917) (🇳🇴 Norway): World War II: The coaster struck a mine and sank in the English Channel off the coast of West Sussex, United Kingdom (50.76333°N, -0.47861°W) with the loss of eight of her nineteen crew.
 * SS Ingerfire (🇳🇴 Norway): World War II: Convoy ONS 2: The cargo ship straggled behind the convoy. She was torpedoed and sunk in the Atlantic Ocean (51.48333°N, -42.98333°W) by GS U-613 with the loss of eight of her 36 crew. Survivors were rescued by HMCS Camrose (K154) and HMCS St. Croix (I81) (both ).
 * SS James W. Denver (🇺🇸 United States): World War II: Convoy UGS 7: The Liberty ship straggled behind the convoy. She was torpedoed and sunk in the Atlantic Ocean 475 nmi west of the Canary Islands, Spain (28.76667°N, -25.66667°W) by GS U-195 with the loss of two of her 67 crew. Survivors were rescued by SS Cabo Huertas, SS Campana, Juan (all 🇪🇸 Spain) and Albufeira (🇵🇹 Portugal) or reached land in their lifeboat.
 * SS Matt W. Ransom (🇺🇸 United States): World War II: Convoy UGS 6A: The Liberty ship, on her maiden voyage struck two mines in the Mediterranean Sea off Casablanca, Morocco (33.91667°N, -7.86667°W) and was damaged. She was abandoned by her 64 passengers and crew, who were rescued by USS PC-471 and USS PC-481 (both ). She was later reboarded by seven of her crew and taken to Casablanca for temporary repairs. Later scuttled as a blockship at Utah Beach, France.
 * SS Runo (🇬🇧 United Kingdom): World War II: The cargo ship was torpedoed and sunk in the Mediterranean Sea 60 nmi north of Bardia, Libya (32.25°N, 23.91667°W) by GS U-593 with the loss of sixteen of her 37 crew.

12 April

 * MV Fresno City (🇬🇧 United Kingdom): World War II: Convoy HX 232: The cargo ship was torpedoed and damaged in the Atlantic Ocean south east of Cape Farewell, Greenland by GS U-563 . She then straggled behind the convoy and was later torpedoed and sunk (54.25°N, -30°W) by GS U-706 . All 45 crew were rescued by HMS Azalea (K25).
 * SS Lancastrian Prince (🇬🇧 United Kingdom): World War II: Convoy ON 176: The cargo ship was torpedoed and sunk in the Atlantic Ocean north east of Newfoundland (50.3°N, -42.8°W) by GS U-404 with the loss of all 45 crew.
 * MV Pacific Grove (🇬🇧 United Kingdom): World War II: Convoy HX 232: The cargo ship was torpedoed and sunk in the Atlantic Ocean south east of Cape Farewell (54.16667°N, -30°W) by GS U-563 with the loss of eleven of the 67 people on board. Survivors were rescued by HMS Azalea (K25).
 * JAPANESE CARGO Sydney Maru : World War II: The cargo ship was bombed and sunk in Hansa Bay, New Guinea (3.3°N, 143.63333°W)  by 5th Air Force B-17s and B-24s. 3 crewman and 7 gunners killed.
 * SS Ulysses (1918) (🇳🇱 Netherlands): World War II: Convoy HX 232: The cargo ship was torpedoed and sunk in the Atlantic Ocean south east of Cape Farewell (54.5°N, -30.5°W) by GS U-563 . All 41 crew were rescued by HMS Azalea (K25).

13 April

 * HNOMS Eskdale : World War II: Convoy PW 323: The Hunt-class destroyer was torpedoed and sunk in the English Channel off Lizard Head, Cornwall by GERMAN TORPEDO BOAT S-90 and GERMAN TORPEDO BOAT S-112 (both ).

14 April

 * HMT Adonis : World War II: The naval trawler was torpedoed and sunk in the North Sea off Lowestoft, Suffolk by Kriegsmarine E-boats with the loss of one crew member.
 * SS Pasvik (🇳🇴 Norway): World War II: The icebreaking tug struck a mine and sank in Varangerfjord (69.91667°N, 30°W) with the loss of nine crew.
 * GS U-526 : World War II: The Type IXC/40 submarine struck a mine and sank in the Bay of Biscay off Lorient, Morbihan, France (47.5°N, -3.75°W) with the loss of 42 of her 54 crew.

15 April

 * HMT Adonis : World War II: The naval trawler was torpedoed and sunk in the North Sea off Lowestoft, Suffolk, United Kingdpm by an E-boat with the loss of 21 of her 32 crew.
 * Archimede : World War II: The Brin-class submarine was bombed and sunk in the Atlantic Ocean off Brazil (-3.38333°N, -30.46667°W)  by a USN Consolidated PBY of Squadron VP 83.
 * MS Borgå (1922) (🇩🇪 Germany): World War II: The cargo ship was torpedoed and sunk in the North Sea 25 nmi north east of Borkum, Lower Saxony by British aircraft with the loss of two crew.
 * SS Clan MacIndoe (🇬🇧 United Kingdom): The cargo ship caught fire in the Mediterranean Sea off Alexandria, Egypt. She was beached on 27 April, but declared a total loss.
 * JAPANESE TRANSPORT India Maru : World War II: The Transport was bombed and sunk at Hansa Bay, New Guinea by 5th Air Force B-17s . 3 Gunners and 7 Crewmen killed
 * SS Kaihei Maru (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Island off the Bonin Islands by USS Seawolf (SS-197).
 * Simson (🇩🇪 Germany): World War II: The tugboat struck a mine and sank off Wrangel Island.
 * USS YP-453 :World War II: The Yard Patrol Craft ran aground and sank on the Bahama Bank.

16 April

 * ITALIAN TORPEDO BOAT Cigno : World War II: Battle of the Cigno Convoy: The Spica-class torpedo boat was torpedoed and sunk in the Mediterranean Sea south-east of Marettimo Island by HMS Pakenham (G06) and  HMS Paladin (G69)   both   . 103 crewmen killed.
 * HMS Pakenham (G06) : World War II: Battle of the Cigno Convoy: The P-class destroyer was torpedoed, shelled and damaged in the Mediterranean Sea off Marettimo, Italy by ITALIAN TORPEDO BOAT Cassiopea and ITALIAN TORPEDO BOAT Cigno (both ). She was scuttled by HMS Paladin (G69) . Ten crew were lost.
 * HMS Ulven : World War II: the submarine struck a mine and sank in the Skagerrak west of Marstrand with the loss of all 33 crew.

17 April

 * SS Fort Rampart (🇬🇧 United Kingdom): World War II: The Fort ship was torpedoed and sunk in the Atlantic Ocean (47.36667°N, -21.96667°W) by GS U-226 and GS U-668 (both ).
 * GS U-175 : World War II: The Type IXC submarine was depth charged and sunk in the Atlantic Ocean (47.88333°N, -22.06667°W) by USCGC Spencer (WPG-36) with the loss of thirteen of her 54 crew.

18 April

 * SS Empire Bruce (🇬🇧 United Kingdom): World War II: The cargo ship was torpedoed and sunk in the Atlantic Ocean (6.66667°N, -13.28333°W) by GS U-123 (1940) . All 49 crew were rescued by HMS MMS-107.
 * SS Fort Rampart (🇬🇧 United Kingdom): World War II: Convoy HX 233: The Fort ship straggled behind the convoy. She was torpedoed and damaged in the Atlantic Ocean (47.36667°N, -21.96667°W) by GS U-628 . She was later torpedoed again by U-628 and then torpedoed, shelled and sunk 900 nmi east north east of the Azores, Portugal (47.46667°N, -22°W) by GS U-226 ( with the loss of six of her 56 crew. Survivors were rescued by HMCS Arvida (K113).
 * MS Høegh Carrier (1935) (🇳🇴 Norway): World War II: The cargo ship was bombed and sunk in the North Sea off Den Helder, North Holland, Netherlands by Royal Air Force aircraft with the loss of two crew.
 * SS Liv ( undefined): World War II: The cargo ship was bombed and sunk at Porto Torres, Sardinia by Royal Air Force aircraft. She was later refloated.
 * HMS P615 : World War II: The Oruç Reis-class submarine was torpedoed and sunk in the Atlantic Ocean (6.81667°N, -13.15°W) by GS U-123 (1940) with the loss of all 43 crew.
 * HMS Regent (N41) : World War II: The Rainbow-class submarine struck a mine and sank in the Strait of Otranto with the loss of all 63 crew.

19 April

 * SS Robert Gray (🇺🇸 United States): World War II: Convoy HX 234: The Liberty ship straggled behind the conovy. She was torpedoed and sunk in the Atlantic Ocean (50.95°N, -40.58333°W) by GS U-108 (1940) with the loss of all 62 crew.

20 April

 * SS El Amirante (🇵🇦 Panama): World War II: Convoy HX 235: The cargo ship foundered in the Atlantic Ocean in a storm. She had previously been in collision with SS Elias Boudinot (🇺🇸 United States).
 * SS Lena Luckenbach (🇺🇸 United States): World War II: Convoy HX 233: The cargo ship collided with SS James Fenimore Cooper (🇺🇸 United States) in the Atlantic Ocean and was abandoned by her 62 crew, who were rescued by MV Lightning (1941) (🇺🇸 United States). Lena Luckenbach was boarded by a salvage party from HMS Bergamot (K189) and beached at Kames Bay. She was later repaired and returned to service.
 * SS Meji Maru No.1 (🇯🇵 Japan): World War II: The cargo ship was torpedoed and sunk in the Pacific Ocean off Honshu by USS Scorpion (SS-278).
 * SS Michigan (1919) (🇺🇸 United States): World War II: Convoy UGS 7: The Design 1013 cargo ship was torpedoed and sunk in the Mediterranean Sea 60 nmi west of Oran, Algeria (35.98333°N, -1.41667°W) by GS U-565 . All 61 people on board were rescued by HMS Foxtrot (T109) and HMT Stella Carina (FY352) (both ).
 * SS Sidi-Bel-Abbès (🇫🇷 France): World War II: Convoy UGS 7: The troopship was torpedoed and sunk in the Mediterranean Sea 10 nmi north of the Habibas Islands, Algeria (35.98333°N, -1.41667°W) by GS U-565 with the loss of 611 of the 1,131 people on board.

21 April

 * SS Ashantian (🇬🇧 United Kingdom): World War II: Convoy ONS 3: The cargo ship was torpedoed and sunk in the Atlantic Ocean north east of St. John's, Newfoundland (55.76667°N, -45.23333°W) by GS U-415 with the loss of sixteen of her 67 crew. Survivors were rescued by HMT Northern Gift.
 * SS Erich Ohlrogge (🇩🇪 Germany): World War II: The cargo ship struck a mine and sank off eastern Jutland, Denmark.
 * USS Grenadier (SS-210) : World War II: The Tambor-class submarine was bombed and damaged in the Strait of Malacca off Penang, Philippines by Japanese aircraft. She was consequently scuttled by her crew the next day at 6.5°N, 97.66667°W. All 76 crew were taken as prisoners of war.
 * SS John Drayton (🇺🇸 United States): World War II: The Liberty ship was torpedoed and sunk in the Indian Ocean (-32.16667°N, 34.83333°W) by ITALIAN SUBMARINE Leonardo da Vinci (.
 * MS Marco Foscarini (1942) ( undefined): World War II: The cargo ship was torpedoed and sunk by HMS Unison (P43) in the Strait of Sicily west of Marsala, Italy (37.83333°N, 11.5°W).
 * MV Scebeli (1936) (🇳🇴 Norway): World War II: Convoy ON 178: The cargo ship was torpedoed and sunk in the Atlantic Ocean (56.11667°N, -44.43333°W) by GS U-191 with the loss of two of her 40 crew. Survivors were rescued by HMS Kale (K241).
 * HMS Splendid (P228) : World War II: The S-class submarine was shelled and damaged in the Mediterranean Sea off Corsica, France by GERMAN DESTROYER Hermes with the loss of eighteen of her 45 crew. She was scuttled to prevent capture before the survivors were rescued and taken as prisoners of war.
 * SS Wanstead (1928) (🇬🇧 United Kingdom): World War II: Convoy ONS 3: The cargo ship straggled behind the convoy. She was torpedoed and damaged in the Atlantic Ocean south east of Cape Farewell, Greenland by GS U-415 with the loss of two of her 50 crew. Survivors were rescued by HMT Northern Gift and HMS Poppy (K213) (both ). Wanstead was later torpedoed and sunk by GS U-413.

22 April

 * MV Amerika (1930) (🇬🇧 United Kingdom): World War II: Convoy HX 234: The cargo liner straggled behind the convoy. She was torpedoed and sunk in the Atlantic Ocean (57.5°N, -42.83333°W) by GS U-306 with the loss of 86 of the 130 people on board. Survivors were rescued by HMS Asphodel (K56).

23 April

 * JAPANESE PATROL BOAT No.39 : World War II: The No.1-class patrol boat was torpedoed and sunk in the Pacific Ocean off the Bonin Islands by USS Seawolf (SS-197).
 * GS U-189 : World War II: The Type IXC/40 submarine was depth charged and sunk in the Atlantic Ocean east of Cape Farewell, Greenland by a B-24 bomber of 120 Squadron, Royal Air Force with the loss of all 54 crew.
 * GS U-191 : World War II: The Type IXC/40 submarine was depth charged and sunk in the Atlantic Ocean south east of Cape Farewell (56.75°N, -36.41667°W) by HMS Hesperus (H57) with the loss of all 55 crew.
 * USS YP-422 : World War II: The Yard Patrol Craft ran aground and sank on the Tumbo Reef, 3 miles south east of the North Bulari Passage, New Caledonia.

24 April

 * Guliola (🇮🇹 Italy) World War II: The transport was torpedoed and sunk in the Mediterranean Sea off Capo di Milazzo, Sicily, Italy by HMS Sahib (P212).
 * HMS Sahib (P212) : World War II: The S-class submarine was depth charged and damaged in the Mediterranean Sea off Capo di Milazzo, Sicily, Italy by Luftwaffe Ju-88, then attacked by ITALIAN TORPEDO BOAT Climene, ITALIAN CORVETTE Gabbiano, and ITALIAN CORVETTE Euterpe, all . She was scuttled by her crew; all 48 were rescued and taken as prisoners of war, one died of wounds later.
 * SS Santa Catalina (1942) (🇺🇸 United States): World War II: The Type C2-S-B1 cargo ship was torpedoed and sunk in the Atlantic Ocean 370 nmi north east of Cape Hatteras, North Carolina (30.7°N, -70.96667°W) by GS U-129 (1941) . All 95 people on board were rescued by MV Venezia (1938) (🇸🇪 Sweden).
 * GS U-710 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean south of Iceland (61.41667°N, -19.8°W) by a Boeing B-17 Flying Fortress aircraft of 206 Squadron, Royal Air Force with the loss of all 49 crew.

25 April

 * GERMAN MINESWEEPER M-471 : World War II: The minesweeper was bombed and sunk by aircraft off Den Helder, the Netherlands.
 * SS Rosenborg (🇬🇧 United Kingdom): World War II: Convoy RU 71: The cargo ship straggled behind the convoy. She was torpedoed and sunk in the Atlantic Ocean (approximately 61°N, -15°W) by GS U-385 with the loss of 28 of her 30 crew. Survivors were rescued by SS Goodwin (🇬🇧 United Kingdom).
 * SS Rouennais (🇫🇷 France): World War II: The cargo ship struck a mine and sank in the Atlantic Ocean off Casablanca, Morocco (34.06667°N, -7.38333°W) with the loss of with the loss of sixteen of her 55 crew.
 * GS U-203 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean off Cape Farewell, Greenland (55.08333°N, -42.41667°W) by Fairey Swordfish aircraft of 811 Squadron, Fleet Air Arm, based on HMS Biter (D97) and by the destroyers HMS Opportune (G80) and HMS Pathfinder (G10) (all ) with the loss of ten of her 48 crew.
 * USS YP-481 : The Yard Patrol Boat grounded and was wrecked in the Atlantic Ocean off Charleston, S.C.

26 April

 * USS YP-47 :World War II: The Yard Patrol Craft was sunk in the Ambrose Channel off Staten Island, New York in a collision with USS YMS-110.

27 April

 * Clan Macindoe ( undefined): The cargo ship was on fire 15th April 1943, off Alexandria. She was subsequently beached and a total loss
 * SS Merope (🇳🇱 Netherlands): World War II: The cargo ship was torpedoed and sunk in the Mediterranean Sea 10 nmi east north east of Cape Bengut, Algeria with the loss of ten of her 34 crew.
 * SS Trondhjemsfjord (1921) (🇳🇴 Norway): World War II: The cargo ship was bombed and sunk in the North Sea off the Ryvingen Lighthouse, Vest-Agder by Allied aircraft.
 * SS Yuzan Maru (🇯🇵 Japan): World War II: The cargo liner was torpedoed and sunk in the Pacific Ocean by USS Scorpion (SS-278).
 * GS U-174 : World War II: The Type IXC submarine was depth charged and sunk in the Atlantic Ocean south of Newfoundland (43.58333°N, -56.3°W) by Lockheed Ventura aircraft of the United States Navy with the loss of all 53 crew.

28 April

 * SS Butterfly ( undefined): World War II: The cargo ship was torpedoed, shelled and sunk in the Gulf of Morbihan off Sept Îles, Morbihan, France by a Motor Torpedo Boat, assisted by HMS Goathland (L27) (both ).
 * SS Kamakura Maru (🇯🇵 Japan): World War II: The troopship was torpedoed and sunk in the Pacific Ocean by USS Gudgeon (SS-211) with the loss of 2,035 of the 2,500 people on board.
 * HMS MTB 639 (MTB639) : World War II: The Fairmile D motor torpedo boat was shelled and sunk off Pantellaria by Sagittaro'''.
 * SS Ortelsburg (🇩🇪 Germany): World War II: Operation Mardonius: The cargo ship was sunk at Oslo, Norway, by saboteurs led by Max Manus.
 * SS Tugela (1921) (🇩🇪 Germany): World War II: Operation Mardonius: The cargo ship was sunk at Oslo, Norway due to sabotage by the Norwegian Resistance. She was later raised, repaired and returned to service.
 * GERMAN PATROL BOAT UJ-1402 : World War II: The patrol boat was shelled and sunk north-west of Lannion, France (48.9°N, -3.8°W).

29 April

 * SS McKeesport (🇺🇸 United States): World War II: Convoy ONS 5: The cargo ship was torpedoed and damaged in the Atlantic Ocean (60.86667°N, -34.33333°W) by GS U-258 with the loss of one of her 68 crew. Survivors were rescued by HMT Northern Gem (FY194) .  Mckeesport was later torpedoed and sunk by U-258.
 * MV Nanking (1924) (🇸🇪 Sweden): World War II: The cargo ship was torpedoed and sunk in the Atlantic Ocean (5.16667°N, -11.16667°W) by GS U-123 (1940) . All 32 crew survived.
 * SS Sturzsee (🇩🇪 Germany): World War II: The cargo ship was torpedoed and sunk by a submarine off Cape Nordkinn, Norway.
 * GS U-332 : World War II: The Type VIIC submarine was depth charged and sunk in the Bay of Biscay north of Cape Finisterre, Spain (45.13333°N, -9.55°W) by a Consolidated B-24 Liberator aircraft of 224 Squadron, Royal Air Force with the loss of all 45 crew.

30 April

 * SS Bandar Shahpour (🇬🇧 United Kingdom): World War II: Convoy TS 37: The cargo ship was torpedoed and sunk in the Atlantic Ocean 130 nmi south west of Freetown, Sierra Leone (7.25°N, -13.81667°W) by GS U-515 with the loss of one of the 78 people on board. Survivors were rescued by HMT Birdlip (T218).
 * SS Corabella (🇬🇧 United Kingdom): World War II: Convoy TS 37: The cargo ship was torpedoed and sunk in the Atlantic Ocean 130 nmi south west of Freetown (7.25°N, -13.81667°W) by GS U-515 with the loss of nine of her 48 crew. Survivors were rescued by HMT Birdlip (T218).
 * MV Kota Tjandi (🇳🇱 Netherlands): World War II: Convoy TS 37: The cargo ship was torpedoed and sunk in the Atlantic Ocean 130 nmi south west of Freetown (7.25°N, -13.81667°W) by GS U-515 with the loss of six of her 77 crew.
 * SS Nagina (🇬🇧 United Kingdom): World War II: Convoy TS 37: The cargo ship was torpedoed and sunk in the Atlantic Ocean 130 nmi south west of Freetown (7.31667°N, -13.83333°W) by GS U-515 with the loss of two of her 113 crew. Survivors were rescued by HMT Birdlip (T218).
 * SS Phoebe A. Hearst (🇺🇸 United States): World War II: The Liberty ship was torpedoed and sunk in the Pacific Ocean north of Fiji (-20.11667°N, 177.55°W) by JAPANESE SUBMARINE I-19.
 * RA-10 : World War II: The ELCO 77'-class Motor Torpedo Boat was bombed and sunk in the Mediterranean Sea off La Goulette, Tunisia by R.A.F. aircraft.
 * GS U-227 : World War II: The Type VIIC submarine was depth charged and sunk in the Atlantic Ocean north of the Faroe Islands (64.08333°N, -6.66667°W) by a Handley Page Hampden aircraft of 455 Squadron, Royal Australian Air Force.

Unknown date

 * USS Pickerel (SS-177) : World War II: The Porpoise-class submarine was depth charged and sunk in the Pacific Ocean east of Honshu, Japan by Japanese forces sometime after 7 April with the loss of all 73 crew.
 * GS U-602 : World War II: The Type VIIC submarine was lost on patrol in the Mediterranean Sea on or after 19 April with the loss of all 48 crew.