For the duration of the war, "Ashtabula" operated in the Ulithi area. In mid-August, Japan capitulated; and, on the last day of the month, the oiler headed for Okinawa, but soon moved on to Jinsen, Korea, where she arrived on 11 September. For the next six months, "Ashtabula" operated between ports in Korea, Japan, and China while supplying and fueling American warships. In March 1946, the oiler made a cruise, via Singapore and Ceylon, to Bahrain. She returned to Japan in April. In June and July, she again visited a Mideastern port, Ras Tanura, Saudi Arabia, to replenish her oil bunkers. "Ashtabula" got underway for a voyage back to the United States. After pausing briefly at Pearl Harbor, the ship arrived at San Pedro, California, on 18 December.