The second ship to be so named by the Navy, Tonawanda (AN-89) was laid down on 12 September 1944, at Sturgeon Bay, Wisconsin, by the Leathem D. Smith Shipbuilding Company; launched on 14 November 1944; sponsored by Mrs. Charles N. Barnum; and commissioned on 9 May 1945.

The net laying ship departed Sturgeon Bay on 19 May and, after a voyage across the Great Lakes and down the St. Lawrence River, arrived in Boston, Massachusetts, on 4 June.

After a short availability, she moved to Melville, Rhode Island, on the 19th for shakedown training and daily net laying drills in Narragansett Bay.

Periodically, she departed the New England coast to conduct underway training and mine warfare tactics exercises in the Chesapeake Bay and off the Virginia Capes.

On two occasions, from 28 August to 21 October 1955 and from 2 May to 30 June 1956, temporary duty with the Mine Warfare Evaluation Detachment, Key West, Florida, interrupted her routine along the New England coast.