she operated there as part of a test and evaluation division. During this period, she visited Guantanamo, Cuba, from February to March 1938; served in the Panama Canal area from January to March 1939; and visited Guantanamo again in February 1940. Her commanding officer from 1936 to 1937 was Lieutenant (later Captain) John P. Cromwell, a future posthumous Medal of Honor recipient for his actions aboard in 1943. From 1941 to 1942 her commander was another future Medal of Honor recipient, Lieutenant (later Commander) Samuel David Dealey. World War II From December 1941 to July 1945, S-20 continued to operate from New London. Her operations were off New England and often included training activities at Casco Bay, Maine. Disposal Departing New London on 2 July 1945, S-20 was decommissioned on 16 July at Philadelphia, Pennsylvania. Her name was struck from the Naval Vessel Register on 25 July. She was sold on 22 January 1946 to North American Smelting Company, Philadelphia for scrapping. References United States S-class submarines World War II submarines of the United States Ships built in Quincy, Massachusetts 1920 ships