(Tug No. 27: dp. 1,000 (n.); 1. 166'8"; b. 30'0"; dr.14'7" (mean); s. 13.0 k. (est.); cpl. 44; a. 1 ma.
The first Tatnuck (Tug No. 27) was laid down on 3 December 1918 by the Puget Sound Navy Yard as losco; launched on 21 February 1919; renamed Tatnuck on 24 February 1919; and placed in commission on 26 July 1919, Lt. (jg.) Christian Christensen in command.
Upon commissioning, Tatnuck was assigned to the 13th Naval District, which encompassed the Pacific northwest and the Alaskan coast. Designated AT-27 on 17 July 1920, she engaged in towing operations for almost all of her 27-year career. The only break came on 16 April 1944, when the Alaska area was established as a separate naval district-the 17th. She did a short tour of duty under the control of the Commandant 17th Naval District, before reverting to the 13th in May. On 15 May 1944, she was reclassified ATO-27.
The tug served just over two years under that designation in the 13th Naval District before being placed out of commission on 12 September 1946. Her name was struck from the Navy list on 29 October 1946. Tatnuck was delivered to the Maritime Commission for disposal on 26 April 1947 and subsequently was sold to the Puget Sound Tug and Barge Co.