USS Seawolf SSN 575

USS Seawolf (SSN-575) was the second nuclear-powered submarine built for the United States Navy, following the pioneering USS Nautilus. Commissioned in 1957, Seawolf was unique for being the only U.S. submarine powered by a liquid metal (sodium-cooled) nuclear reactor, though it was later converted to a more conventional pressurized-water reactor due to maintenance challenges. Throughout her service, Seawolf participated in a variety of experimental operations and Cold War patrols, advancing submarine technology and tactics. She was decommissioned in 1987, leaving a legacy of innovation in naval nuclear propulsion.