Submarines of the Imperial Japanese Navy
Imperial Japanese Navy (IJN) submarines formed by far the most varied fleet of submarines of World War II, including manned torpedoes ("Kaiten"), midget submarines ("Kō-hyōteki", ), medium-range submarines, purpose-built supply submarines (many used by the Imperial Japanese Army, see Type 3), fleet submarines (many of which carried an aircraft), submarines with the highest submerged speeds of the conflict ("Sentaka" ), and submarines able to carry multiple bombers (World War II's largest submarine, the Sentoku ). They were also equipped with the most advanced torpedo of the conflict, the oxygen-fuelled Type 95 (which are sometimes confused with the famed Type 93 Long Lance torpedo).
Japanese submarine I-15
I-15 was a Japanese B1 type submarine. She was completed at Kure Navy Yard on September 30, 1940, whereupon she entered into service with the Imperial Japanese Navy. Her first and only commanding officer was Commander Nobuo Ishikawa. "I-15" operated off the north coast of Oahu during the raid on Pearl Harbor. Her second wartime patrol, in May and June 1942, took her to the Aleutians, where she conducted reconnaissance of several islands. "I-15"s third and final patrol took place from August to November 1942, when she operated in the Solomon Islands in the South Pacific, supporting the Japanese efforts to hold Guadalcanal. One source (Morison) suggests that "I-15" hit the battleship with a torpedo on September 15, 1942. More recent authorities (Hackett & Kingsepp) maintain that the torpedo came from another submarine operating in the area, , which was also responsible for the sinking of , which "I-15" duly observed and reported. On November 10, 1942, a U.S. ex-destroyer (modified to a fast minesweeper), , sank "I-15" at Cape Recherche, San Cristóbal, with all hands lost.
Commander Ishikawa was promoted to the rank of Captain posthumously. On December 14, 1942, more than one month after "I-15" was sunk, sank an unknown submarine which it misidentified as the "I-15".