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-124
The submarine was the fourth Japanese submarine lost in action in World War II. It has been surrounded in controversy since it was lost. In World War II there were claims that two submarines had been lost in the attack on Darwin; that its crew remained alive for some time; and that divers heard crew movement inside the hull. Later it was reported by both Japanese and American sources that "the "I 124" with her Division Commander Keiyu Endo, embarked, sank with all those on board in water only forty feet deep. US Navy divers were sent down and entered the submarine, and removed naval code books, a godsend for the Navy codebreakers at Pearl Harbor". However, this was later disproved by historian Dr Tom Lewis, in his book "Sensuikan I-124"; later re-published as "Darwin's Submarine I-124".