Fukuryu

Fukuryu (Japanese: 伏龍, Hepburn: Fukuryū) were a part of the Japanese Special Attack Units prepared to resist the invasion of the Home islands by Allied forces. The name literally means "crouching dragon," and has also been called "suicide divers" or "kamikaze frogmen" in English texts.

They were armed with a mine containing 15 kg (33 lb) of explosive, fitted to a 5 m (16 ft) bamboo pole. They would dive and stick the pole into the hull of an enemy ship, destroying themselves in the process. They were equipped with a diving jacket and trousers, diving shoes, and a diving helmet fixed by four bolts. They were typically weighed down with 9 kg (20 lb) of lead, and had two bottles of compressed air at 150 bar (2,200 psi). They were expected to be able to walk at a depth of 5–7 m (16–23 ft), for a period of about six hours.

Several deaths occurred during training due to malfunctions. Since Japan surrendered before the invasion of the Japanese mainland occurred, this tactic was never used in actual combat. However, there are reports of some strikes that allegedly made use of such weapon: