1864, February 17 – Confederate human-powered submarine H. L. Hunleysinksthe Union sloop with spar torpedo, off Charleston. The H. L. Hunley thus became the first submarine to successfully sink an enemy vessel in combat, and was the direct progenitor of what would eventually become international submarine warfare.
First Balkan War
1912, December 9 – became the first submarine to launch a self-propelled torpedo at an enemy ship, though the ship did not sink due to a weapons malfunction.
1914, September 5 – HMS Pathfinder is sunk at the start of World War I by, becoming the first ship to ever be sunk by a self-propelled torpedo fired by submarine.
1914, October 18 – German submarine sinks in the first ever successful attack on one submarine by another.
1914, October 20 – German submarine sinks in the first submarine sinking of a merchant ship during the world wars.
1915, May 7 – German submarine sinks killing 1,198 and leaving 761 survivors. The sinking turned public opinion in many countries against Germany, contributed to the U.S. entry into World War I.
1915, May 25/27 – In the morning of May 27 German submarine U-21 sinks the British pre-dreadnought battleship off the Gallipoli peninsula. Two days after the same U-boat sunk the pre-dreadnought HMS Triumph near Gaba Nepe.
1916, March 22 – German submarine is sunk by the Q-ship – a merchant ship carrying hidden weapons – HMS Farnborough in the first successful use of depth charges.
1939, October 14 – German U-boat sinks HMS Royal Oak in Scapa Flow base. The First Lord of Admiralty Winston Churchill officially announced the loss of Royal Oak to the House of Commons, first conceding that the raid had been "a remarkable exploit of professional skill and daring".
1940, November 23 – sinks 7 Allied Merchant ships from Convoy SC-11 in only 3 hours.
1941, November 13 – U-81 strikes with a single torpedo. She sinks the following day due to crippling damage.
1942, September 15 – Japanese submarine I-19 sinks U.S. aircraft carrier and destroyer and damages battleship with a single salvo.
1943, March 16–19 – The largest North Atlantic U-boat wolfpack attack of the world wars sinks 22 ships from Convoys HX 229/SC 122.
1943, April 29 – May 6 – Convoy ONS 5 is the last major North Atlantic wolfpack attack by surfaced U-boats as escorts demonstrate effective use of radar to sink 6 U-boats in low-visibility conditions.
1944, November 29 – USS Archer-Fish sinks Japanese aircraft carrierShinano, the largest vessel of that time.
1943, October 31-November 1 – USS Borie and U-405 engage in a pitched battle ending with Borie ramming the submarine. Both ships are lost.
1945, January 30 – Soviet submarineS-13 sinks the German ship Wilhelm Gustloff, with older and cautious estimates of 6,000 but more recent estimates of more than 9,000 casualties.
1945, February 6 – Royal Navy submarine becomes the only submarine to sink another submarine while they were both submerged when she sinks off Norway.
1945, April 16 – Soviet submarine L-3 sinks the German ship Goya, with 6,000–7,000 casualties.
Post-World War II
1971, December 9 – Pakistani PNS Hangor during the 1971 Indo-Pakistani War sinks the Indian frigate. This was the first ship sunk by a submarine since World War II. Hangor also damaged another warship, INS Kirpan. This was the heaviest casualty that the Pakistani Navy inflicted on the Indian Navy in the war. After the attack on Khukri, the Indian Navy ceased its attacks on Karachi and moved the focus of its operations to East Pakistan ports like Chittagong and Cox's Bazaar.
1982, May 2 – British nuclear submarine HMS Conqueror sinks Argentine cruiser General Belgrano off the Falkland Islands. It was the first sinking of any vessel by a nuclear-powered submarine in wartime and also the first time that a nuclear-powered submarine fired weapons in an act of war. The sinking was controversial since the Argentine ship was claimed to be outside of the conflict zone at the time of attack.
