From 8 July 1941 to May 1942 Delta carried cargo from east coast ports to Guantanamo Bay, Cuba; Puerto Rico; Bermuda; Argentina; Newfoundland, Halifax, and Nova Scotia, Canada; and Reykjavík, Iceland.

She returned to Norfolk Naval Shipyard for overhaul on 27 April 1945, and on 15 June sailed for Pearl Harbor for a month of repair duty.

On 26 August, she arrived at Yokosuka Naval Base for general fleet repair work, including the assignment of preparing Nagato, the former Japanese battleship, for the atomic weapons tests of 1946 at Bikini.

Recommissioned 1 November 1950, Delta arrived at San Diego on 8 March 1951 to provide repair services to ships of the Pacific Fleet there and at Long Beach, California as well as on periodic deployments to the Far East.

Delta was stricken from the Naval Register on 1 October 1977 and transferred to the Maritime Administration (MARAD) for lay up in the National Defense Reserve Fleet.