Submarine No.71

Submarine No.71 (Number 71) was an experimental submarine of the Japanese Imperial Navy completed in 1938. The submarine was capable of a submerged speed of 21 knots, five years before the famous German type XXI U-boats achieved speeds of around 18 knots. After extensive evaluations the submarine was scrapped in 1941, however the lessons learned lead to the development of the Sen Taka-class, and the Sen Taka Sho-class.