While submarines were invented centuries ago, development of self-propelled torpedoes during the latter half of the 19th century dramatically increased the effectiveness of military submarines.

Initial submarine scouting patrols against surface warships sank several cruisers during the first month of World War I. Incidental submarine encounters with merchant ships were performed by signalling ships to stop, then sinking them after evacuation of the crew, in accordance with international law. After unrestricted submarine warfare began in February 1915, any ship could be sunk unexpectedly from the heavy underwater hull damage inflicted by torpedoes. Many large ships sank without their crews being able to alert friendly forces in time, and the submarines which sank them were too small to rescue more than a few survivors.

Many personnel casualties continued through World War II, and there have been a few later sinkings.

List of ships sunk by submarines by death toll (exceeding 150) Deaths Name Type National affiliation Date Submarine National affiliation 9,343 Cruise ship converted into a military transport serving as evacuation ship 6,500 Freighter converted into a troop transport serving as evacuation ship 5,620 Jun'yō Maru Prisoner transport 5,400 Toyama Maru Troopship 4,998 Ryūsei Maru Troopship 4,406-4,755 Landing craft carrier 3,608 Ocean liner converted into a troop transport serving as evacuation ship 3,546 Landing craft carrier 3,219 Nikkin Maru Troopship 3,000 Tango Maru Prisoner transport 2,765 Troopship 2,670 Prisoner transport 2,665 Teia Maru Troopship 2,649 Troopship 2,495 Yoshino Maru Troopship 2,475 Sakito Maru Troopship 2,246 Landing craft carrier 2,134 Hawaii Maru Troopship 2,113 Edogawa Maru Troopship 2,089 Dainichi Maru Troopship 2,035 Kamakura Maru Troopship 2,008 Ocean liner 2,000 Ural Maru Ocean liner 2,000Antony Preston, Warship 2001-2002, p. 79Donald A Bertke, Gordon Smith, Don Kindell, World War II Sea War, Vol 7: The Allies Strike Back p. 179Mikhail Monakov, Jurgen Rohwer, Stalin's Ocean-going Fleet: Soviet Naval Strategy and Shipbuilding Programs 1935–1953, p. 266 Salzburg Transport ship serving as prisoner transport 1,934 Nichiren Maru Troopship 1,926 Other sources say 1,750 victims. Troopship 1,773 Arisan Maru Prisoner transport or 1,747 Arabia Maru Troopship 1,704 Denmark Maru Troopship 1,658 Ocean liner/Troopship 1,650 Aircraft carrier 1,602 Daisyō Maru Troopship 1,576 Marei Maru Troopship 1,540 Kōshū Maru Prisoner transport 1,539 Kenzui Maru Troopship 1,529 Tsushima Maru Cargo liner serving as evacuation ship 1,471 Jinyō Maru Troopship 1,451 Hakuyo Maru Troopship 1,450 Maebashi Maru Troopship 1,435 Aircraft carrier 1,428 Shiranesan Maru Troopship 1,400 Tatsuta Maru Troopship 1,394 Mizuho Maru Troopship 1,384 Fuso Maru Troopship 1,338 Troopship 1,310 Awata Maru Troopship 1,300 Heavy cruiser 1,291 Troopship 1,279 Troopship 1,273 Tsuyama Maru Troopship 1,272 Aircraft carrier 1,262 Nichiran Maru Troopship 1,250 Escort carrier 1,240 Aircraft carrier 1,197The official figures give 1195 lost out of 1959, excluding three stowaways who also were lost. The figures here eliminate some repetitions from the list and people subsequently known not to be on board. Ocean liner 1,200 Takachiho Maru Ocean liner 1,200 Battleship or battlecruiser 1,188 Troopship 1,184 Rashin Maru Troopship 1,159 Rakuyo Maru Prisoner transport 1,130 Escort carrier 1,118 Hakozaki Maru Ocean liner 1,073 Fukuyo Maru Troopship 1,053 Montevideo Maru Prisoner transport 995 Troopship 956 Taihei Maru Troopship 935 Troopship 921 Other sources say 600–700 killed. Città di Palermo Armed merchant cruiser serving as troopship 930 Troopship 883 Heavy cruiser 880 Troopship 870 Troopship 866ALberto Santoni, Il vero traditore. Il ruolo documentato di Ultra nella guerra del Mediterraneo, pp. 257–258 Cargo ship serving as POW ship 865 Ocean liner serving as POW ship 862 Battleship 856 Troopship/POW ship 856 Tenryō Maru Troopship 846 Lisbon Maru Prisoner transport 819 Troopship 817 Taiyō Maru Ocean liner 810 Akane Maru Troopship 800 Troopship 786 Battleship 768 Motor schooner 754 Ocean liner 747 Escort carrier 740 Troopship 700 Coastal merchant ship serving as POW ship 688 Shinyō Maru Prisoner transport 686 Taisei Maru Troopship 684 Léon Gambetta Armored cruiser 683 Anti-Air cruiser 675 Troopship 672 Armored cruiser 668 Nikkō Maru Passenger and cargo ship 667 Taito Maru Cargo ship serving as evacuation ship 658 Tateyama Maru Troopship 656 Sanka Maru Troopship 654 Ocean liner 648 Pre-dreadnought battleship 644 Escort carrier 643 Armored cruiser 638 Troopship 638 Cable layer serving as evacuation ship 615 Prisoner transport 611 Sidi-Bel-Abbès Troopship 610 Troopship 599 America Maru Ocean liner serving as evacuation ship 597 Protected cruiser 595 Prisoner transport 574 Landing craft carrier 570Giuseppe Fioravanzo, "La Marina italiana nella seconda guerra mondiale – Volume II – La guerra nel Mediterraneo – Le azioni navali – Tomo Secondo: dal 1° aprile 1941 all’8 settembre 1943", Ufficio Storico della Marina Militare italiana Heavy cruiser 564 Irish Sea Ferry 562 Armored cruiser 555 Euterpe Troopship 547 Pre-dreadnought battleship 544 Troopship 527 Armored cruiser 526 Protected cruiser 523 Aden Maru Troopship 518 Aircraft carrier 514 Escort carrier 503 Nankin Maru Troopship 500~ Troopship 497 Tembien Cargo ship serving as POW ship 488 Prisoner transport 484 Troopship 484Other sources (Giorgio Giorgerini, La guerra italiana sul mare. La Marina fra vittoria e sconfitta 1940–1943, and Gianni Rocca, Fucilate gli ammiragli. La tragedia della Marina italiana nella seconda guerra mondiale) says 500 victims, other 464. Light cruiser 470 Light cruiser 461 Ikoma Maru Prisoner transport 452 Kenjo Maru Troopship 450 Troopship 450 Light cruiser 448 Seisho Maru Troopship 440 Prisoner transport 436 Ocean liner 432 Città di Messina Troopship 419 Light cruiser 417 Light cruiser 414 Troopship 400 Troopship 392 Troopship 381 Light cruiser 379 Ocean liner 375 Armored cruiser 374 Armored cruiser 373 Merchant ship 369 Q-ship 364 Blockade runner 362 Ocean liner 360 Cargo and passenger liner 360 Ocean liner 360 Heavy cruiser 349 Light cruiser 344 Troopship 343 Emma Cargo ship/Troopship 336 Heavy cruiser 336 Aviso/Sloop 334 Ocean liner 330 Light cruiser 323 Light cruiser 320 Sebastiano Venier Cargo ship serving as POW ship 307 Destroyer 305 Motor schooner 300 Other sources say about 330 people were killed. Andrea Sgarallino Passenger ship 272 Troopship 270Scheina, Robert L. "Latin America's Wars Volume II: The Age of the Professional Soldier, 1900-2001" Potomac Books, 2003. p. 161. Cargo liner 268Hospital ship 194 Frigate 193 Aircraft carrier 187MV Ciudad de BarcelonaOcean Liner Second Spanish Republic30 May, 1937General Sanjuro

See also List of maritime disasters

References