when was the last time a us submarine sunk
List of lost United States submarines The USS R-1 (SS-78), originally commissioned on 16 December 1918 and decommissioned after more than 12 years of service, was recommissioned and served for five additional years during WWII. R-1 was decommissioned at Key West on 20 September 1945 and was struck from the Naval Vessel Register on 10 November. Still at Key West awaiting disposal on 21 February 1946, the submarine sank in 21 feet (6.4 m) of water. Raised three days later, she was sold for scrap on 13 March 1946