The first Gannet was laid down 1 October 1918 by the Todd Shipyard Corp., N.Y.; launched 19 March 1919; sponsored by Miss Edna Mae Fry; and commissioned at the New York Navy Yard 10 July 1919, Lt. J. E. Armstrong in command.

Gannet departed New York 11 August 1919 and reached San Diego, Calif., 2 November after training out of Guantanamo Bay, Cuba. A unit of the Train, Pacific Fleet, she based at San Diego and was subsequently assigned to Aircraft Squadron, Battle Fleet, and later to Base Force, U.S. Fleet. Serving primarily as a tender to aircraft squadrons, she also performed towing, transport, and passenger service along the western seaboard, and made periodic cruises as tender to aircraft units participating in Army-Navy exercises, fleet problems, and maneuvers off Hawaii, the Panama Canal, and in the Caribbean Sea. She spent the summer months of 1926, 1929, and 1932-35 as tender to aerial survey expeditions to Alaska and the Aleutian Islands. On 30 April 1931 Gannet was designated a minesweeper for duty with aircraft. She was reclassified AVP-8, 22 January 1936.

Gannet departed San Diego 18 August 1937 and based at Coco Solo Panama, as tender for aircraft squadrons of the Scouting Force until 1 June 1939. Arriving Norfolk 9 June, she then became tender to Patrol Wing 5, Aircraft Scouting Force. In a series of cruises from Norfolk, she tended Navy patrol planes based at Key West, Bermuda, Santa Lucia, and Trinidad, then steamed north 22 September 1941 to establish an advance seaplane base at Rungnait Bay, Greenland (6-23 October). She served on plane guard station in the Davis Strait for an Iceland- Argentia ferry flight before returning to Norfolk 11 November.

Gannet was tending patrol planes at Hamilton, Bermuda, when the Japanese struck Pearl Harbor. She returned to Norfolk 12 December and sailed 21 January 1942 for Bermuda to serve as tender to Patrol Squadron 74, which provided air patrol and coverage in approaches to that base Gannet also was communication center for all aircraft operations in that area.

Departing Bermuda 2 June, Gannet joined British ship HMS S.umarr the next day in an unsuccessful search for the torpedoed merchantman Westmoreland. Ordered back to base the afternoon of 6 June, the two warships became separated during the night. Before dawn 7 June, northwest Or Bermuda, Gannet was hit by submarine torpedoes. She went down so rapidly that her decks were awash within 4 minutes, and she carried 14 of her crew down with her. Her commanding officer, Lt. Francis E. Nuessle, fought free of the suction, joined other survivors, and ordered the life rafts tied together in the heavy seas with wounded hoisted on board and the uninjured hanging on the sides. Twenty-two men were rescued by two planes of Patrol Squadron 74 which made the daring landing in heavy seas. Hamilton (DMS-18), led to the scene by one of the same planes, rescued 40 others.