USS Nanigo (YTB-537/YTM-537), a harbor tug of the United States Navy, was laid down on 6 December 1944 by the Consolidated Shipbuilding Corp., Morris Heights, New York, launched on 27 March 1945; and placed in service on 30 August 1945.

Designed for harbor duties of towing, firefighting, and assisting ships in berthing and docking, Nanigo - initially allocated to the 3rd Naval District - was assigned to Task Force 23 for shakedown training and availability.

Arriving on the 29th, she reported for duty under Atoll Commander, Kwajalein, as relief for YTM-469 and joined in preparing that island for the increased shipping expected in connection with the forthcoming Operation Crossroads, the 1946 atomic test series.

On 7 February 1970, the tug brought the U.S. fishing vessel Aleutian Queen, that had lost steering control 130 miles (210 km) northwest of Adak, into port for repairs.

On 3 August 1970, when the captain's gig ran aground with a fishing party 100 feet (30 m) offshore in Finger Bay, Nanigo and a station medium landing craft (LCM) retrieved the fishermen without incident.