(WYT‑91: dp. 328; l. 110'; dr. 11'; s. 8 k.; cl. 110'B)
Built by Gulfport Works, Port Arthur, Tex., as a medium harbor tug with steel strengthened hull for icebreaking, Mahoning was launched 22 July 1939.
Assigned to the 3d Coast Guard District at New York City, she operated in and about New York Harbor. Executive Order 8929 of 1 November 1941 transferred the entire Coast Guard to the Navy. Mahoning continued operations in New York Harbor as part of the naval forces until 1 January 1946. Executive Order 9666 of 28 December 1945 returned her to the Coast Guard.
New York City remained her permanent headquarters throughout the post‑World War II years. In 1966 she was redesignated WYTM‑91, and she has continued to operate as a tug in New York Harbor into 1969.