DSV Sea Cliff

DSV-4 (ex-Sea Cliff) is a 25-ton, manned deep-ocean research submersible owned by the United States Navy, now known only by its hull number, not by its former name.

DSV-4 is an Alvin-class Deep Submergence Vehicle (DSV). a sister ship to DSV Turtle (DSV-3) and DSV Alvin (DSV-2). The Alvin-class DSVs were designed to replace older DSVs, such as the less-maneuverable Trieste-class bathyscaphes.DSV-4 originally had a maximum dive depth of 6,500 feet (2,000 meters), as all Alvin-class DSVs did at first. It was redesigned to dive to 20,000 feet (6,096 meters) and refitted in 1984. With the refit of DSV-4, the bathyscaphe DSV-1 (ex-Trieste II) was retired from service.

DSV-4 has a plug hatch 2 feet (0.61 meter) in diameter, held in place mechanically with hatch dogs and, while submerged, by the pressure of the water above it. DSV-4 can dive 5,000 feet (1,524 meters) deeper than the famed Alvin; however, the Super ''Alvin''-class replacement for DSV-2 is designed to dive to 22,000 feet (6,705 meters).

Sea Cliff was retired from active service in 1998 and subsequently given to Woods Hole Oceanographic Institution [1]. The Naval Vessel Register shows DSV-4 was returned to active U.S Navy service on 30 September 2002 in the custody of Woods Hole [2], but a New York Times article indicates that it was cannibalized for parts for DSV Alvin [3].

See also

• Deep Submergence Vehicle
• Deep Submergence Rescue Vehicle
• Bathyscaphe Trieste (DSV-0)
• Bathyscaphe Trieste II (DSV-1)

Alvin class DSV

• Alvin (DSV-2)
• Turtle (DSV-3)
• Sea Cliff (DSV-4)

External links

• ex-SEA CLIFF in the Naval Vessel Register
• Deep Submergence Vehicles article at the Federation of American Scientists web page