DSV-4 SEA CLIFF

DSV-4 SEA CLIFF is a deep submergence vehicle (DSV) operated by the United States Navy. Commissioned in 1968, SEA CLIFF was designed for deep-ocean search and recovery missions, scientific research, and covert operations. Over the course of its service, SEA CLIFF underwent several upgrades, most notably in 1984, when it was modified to reach depths of 20,000 feet, making it one of the deepest-diving crewed submersibles in the U.S. Navy at the time. The vessel played a key role in numerous recovery operations, including the retrieval of sensitive military equipment from the ocean floor, before its retirement in 1998.