German submarine U-731

German submarine U-731 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 1 October 1941 at the Schichau-Werke yard at Danzig, launched on 25 July 1942, and commissioned on 3 October 1942 under the command of Oberleutnant zur See Werner Techand.

Attached to 8th U-boat Flotilla based at Kiel, U-731 completed her training period on 30 April 1943 and was assigned to front-line service.

Service history
On the fourth and final war patrol, U-731 was detected on 15 May 1944 by two Catalinas, P-14 and P-1, of VP-63 off Tangiers, when the U-boat tried to force the Strait of Gibraltar. Two British patrol craft, HMS Kilmarnock and HMS Blackfly, received reports of the U-boat and attackedwith hedgehogs. U-731 was sunk in position 35.9°N, -5.75°W, all 54 crew members perished in the attack.