Departing New York on 2 February 1921, Keosanqua sailed for Hawaii via Charleston, the Panama Canal, and San Diego.

Arriving Pearl Harbor on 16 April 1921, the tug was based at the Navy Yard there, towing ships and targets until she decommissioned on 8 June 1922.

Duty with submarines continued until January 1938, when she commenced towing operations with the Pacific Fleet, participating in joint Army-Navy maneuvers off Oahu during May 1939.

On 7 December 1941, Keosanqua was taking over a tow from Antares southwest of the entrance to Pearl Harbor when the infamous Japanese raid began.

Transferred to the Maritime Commission on 11 July 1947 for disposal, she was sold the same day to Puget Sound Tug & Barge Co., Seattle, Wash. Resold to a Canadian shipping firm in 1948, she was renamed Edward J. Coyle.