Departing New London 24 April 1946, Cusk made an extended cruise through the Caribbean Sea, and arrived at San Diego 6 June 1946.

She entered Mare Island Naval Shipyard for a "Fleet Snorkel" conversion and modernization in 1954, but remained in the Regulus missile program because of her special guidance equipment, although redesignated SS-348 on 1 July 1954.

After successfully shooting a MK 14 Mod 3 warshot torpedo at the target cliffs on Kahoolawe Island she departed for WesPac in January 1962.

following the successful mine plant Cusk returned to Subic Bay RP, and retrieved her MK 14 Mod 3 warshot torpedoes.

Subsequently, the Cusk was redesignated AGSS-348 and she set sail for the last time in September 1969 for Hunter's Point Naval Shipyard in San Francisco.