USS Seawolf (SSN-21), the lead ship of her class, is the fourth submarine of the United States Navy named for the seawolf, a solitary fish with strong, prominent teeth and projecting tusks that give it a savage look. The contract to build her was awarded to the Electric Boat Division of General Dynamics and Newport News Shipbuilding on 9 January 1989 and her keel was laid down on 25 October 1989. She was launched on 24 June 1995, sponsored by Mrs. Margaret Dalton, and commissioned on 19 July 1997 with Commander David M. McCall in command.
Seawolf was a product of the Cold War, designed as a replacement for the Los Angeles-class submarines and as a response to the Soviet Akula class. It is said that the Seawolf is quieter at its tactical speed of 25 knots (46 km/h; 29 mph) than a Los Angeles submarine is pierside. Originally 29 were planned for production, but with the end of the Cold War, the cost was judged to be prohibitively high and only 3 were built in favor of the smaller Virginia-class submarines, which were expected to be about 10% cheaper.
Between 25–27 March 2006, a series of anti-submarine warfare exercises were held in Hawaiian waters that included the Seawolf; Carrier Strike Group Nine; the nuclear-powered attack submarines Cheyenne, Greeneville, Tucson, and Pasadena, as well as land-based P-3 Orion aircraft from patrol squadrons VP-4, VP-9, and VP-47.
On 22 July 2007, the submarine transferred from its previous homeport of Naval Submarine Base New London in Groton, Connecticut, to permanently reside at Naval Base Kitsap in Bremerton, Washington.
Adding support personnel as well as ship's crew, there are 140 personnel attached to the Seawolf.