(SS‑204: dp. 825 (surf.), 1,179 (subm.); l. 238'11", b. 21'8"; dr. 12'1" (mean); s. 16 k. (surf.), 9 k. (subm.) cpl. 38; a. 1 3", 6 21" tt.; cl. Mackerel)
An edible fish of the North Atlantic.
Mackerel (SS‑204) was laid down by the Electric Boat Co., Groton, Conn., 6 October 1939; launched 28 September 1940; sponsored by Mrs. Wm. R. Furlong; and commissioned 31 March 1941, Lt. John F. Davidson in command.
Throughout World War II, Mackerel, assigned to Submarine Squadron 1 at New London, Conn., participated in the training and improvement of the Navy's submarine force. Designed as an experimental submarine, she provided support services to the Underwater Sound Laboratory and training services to the Submarine and the Prospective Commanding Officers Schools at New London, in addition to training Allied surface vessels and aircraft in antisubmarine warfare.
Although most of her time was spent in the New London area, she steamed as far north as Casco Bay and as far south as Chesapeake Bay to conduct antisubmarine training exercises. While in the New London‑Narragansett Bay area she often worked with TG 28.4, the antisubmarine development detachment, as well as with the Underwater Sound Laboratory; thus aiding, both tactically and technically, in the development of submarine knowledge.
During the course of the war, Mackerel made only one contact with the enemy. Having departed New London 12 April 1942, she proceeded, on the surface, to Norfolk, Va., to conduct antisubmarine training exercises for Army and Navy aircraft. On the night of the 14th her lookouts sighted the wakes of two torpedoes heading for the submarine. Evasion maneuvers proved effective and Mackerel, undamaged, launched two torpedoes at a surfaced enemy submarine. The enemy, dodging Mackerel's torpedoes, gathered speed and soon out‑distanced the training submarine. The following morning another, or the same, enemy submarine was sighted, but Mackerel was again out‑distanced.
At the end of the war, Mackerel was ordered to Boston, where she decommissioned 9 November 1945. She was struck from the Navy list 28 November 1945 and sold for scrap, to the North American Smelting Co., Philadelphia, Pa., 24 April 1947.