[1] Originally laid down as SS Mission San Lorenzo under a United States Maritime Commission contract on 9 June 1944 at Sausalito, California by the Marinship Corporation, she was renamed USS Abatan on 25 July 1944 in anticipation of her acquisition by the Navy and simultaneously designated AO-92 for naval service as an oiler, launched on 6 August 1944, sponsored by Mrs. John A. McCone, transferred to the Navy on 28 November 1944 at the Mare Island Navy Yard, Vallejo, California, converted there for naval service, completed as a distilling ship, redesignated USS Abatan (AW-4) on 24 August 1944 and placed in commission on 29 January 1945.

After pausing en route at Eniwetok, Abatan reached Ulithi on 21 March and remained there for more than six months providing potable water to various types of landing craft, patrol vessels, and escort ships.

The ship sailed for Okinawa on 1 October, and stopped en route at Samar, Philippine Islands, to take on fresh water before continuing on to the Ryukyus.

Abatan reached Eniwetok on 31 May and assumed duties in connection with "Operation Crossroads," a series of tests conducted to determine the effects of atomic explosions upon warships.

The vessel visited Pearl Harbor, Hawaii, in late July; transited the Panama Canal; reported to the Atlantic Fleet in mid-August; and then proceeded to Philadelphia, Pennsylvania.