Submarines of the Imperial Japanese Navy
Imperial Japanese Navy submarines originated with the purchase of five Holland type submarines from the United States in 1904. Japanese submarine forces progressively built up strength and expertise, becoming by the beginning of World War II one of the world's most varied and powerful submarine fleets.
Submarines of the Imperial Japanese Navy
The submarines were also able to carry three Aichi M6A "Sei ran" aircraft, each carrying an bomb at . To fit the aircraft in the hangar the wings of the aircraft were folded back, the horizontal stabilizers folded down, and the top of the vertical stabilizer folded over so the overall profile of the aircraft was within the diameter of its propeller. A crew of four could prepare and get all three airborne in 45 minutes launching them with a 120-foot (37 m) catapult on the fore deck of the giant submarine.