After two trips to the Orient she was acquired by the United States Navy and commissioned as a cargo ship, USS Hamul (AK-30), on 14 June 1941 at Charleston, South Carolina.

Departing Mobile 7 January 1943 redesignated as AD-20, Hamul tended destroyers and other ships in Casco Bay, Maine until April and then sailed south to serve as flagship of the Destroyer-Escort Shakedown Task Group in Bermuda.

After overhaul at the Brooklyn Navy Yard, Hamul sailed for the Pacific 1 January 1945 reaching Saipan 12 February via the Panama Canal, Pearl Harbor, and Eniwetok.

At Ulithi Hamul kept busy repairing damaged craft returning from the Okinawa campaign until 6 May, when she sailed for the scene of the Pacific war's last major struggle.

Going west via Norfolk, Virginia, Hamul reached Sasebo, Japan on 23 October and began servicing the fleet operating off the Korean coast.