1943–1950

Foss sailed from Boston on 22 September 1943 for the Netherlands West Indies to escort a tanker convoy back to New York. From New York, she put to sea once more on 13 October, again with a group of tankers and, after calling at Aruba, crossed the Atlantic to Dakar, Oran and Algiers, returning by way of Aruba and the Canal Zone to New York. Between 26 December and 9 October 1944, Foss operated on the New York-Derry convoy route, making seven voyages to build up forces in Europe for the Normandy invasion and to support the advance on the continent once the landings had been made.

Assigned to operational development activities in anti-submarine warfare, Foss sailed out of Washington, New London, Charleston, Norfolk, and ports in Florida during the next six years. She tested equipment for the Naval Research Laboratory and conducted operations under the direction of the Fleet Sonar School, the Anti-submarine Development Detachment, and the Operational Development Force. In 1946, she was equipped with ship/shore power conversion equipment, with which, during the winter of 1947–48, she provided Portland, Maine, with emergency electric power after normal power resources had failed because of forest fires and lack of rain. In August 1950, Foss took part in rocket experiments at Cape Canaveral, recording data after seaward firings.

1950–1957

Reassigned to the Pacific Fleet, Foss departed Norfolk on 29 September 1950, reaching San Diego on 11 October. Six days later, she sailed for duty in Korea, where her special ability to provide power to the shore was used at Chinnampo, Inchon, and Hŭngnam in November and December. She arrived at Ulsan Man on 25 December and remained until 18 August 1951, providing power for an Army unit stationed there.

Returning to San Diego on 10 September, Foss served in ordnance tests until 21 September, when she raised Pearl Harbor, her new home port. During the next five years, she operated locally in the Hawaiian Islands, as well as making two cruises on surveillance patrol through the islands of the Pacific Trust Territory and two tours of duty in the Far East. During her 1955 tour, she served as station ship at Hong Kong.

Decommissioning and fate

In June 1957, Foss returned to the west coast and was decommissioned and placed in reserve at Mare Island Naval Shipyard on 30 October 1957. On 6 September 1966, Foss was sunk as a target by USS Sabalo (SS-302) off the coast of California near San Diego.