Washington has a couple of interesting deep diving vessels in its parking lot.
DSRV Mystic
The deep submergence rescue vehicle (DSRV) Mystic provided rapid-response submarine rescue capability to the U.S. Navy from 1970 to 2008. According to the museum:
“The DSRVs had to hover precisely in place, a difficult task given water currents and deep ocean pressure.”
The DSRVs could reach a disabled submarine anywhere in the world with 72 hours and could operated down to 5,000 feet.
According to the Museum:
“Although the Navy conducted numerous practice exercises with the DSRVs, they have never been used for a real rescue operation. No American submarine has sunk since the DSRV program began.”
Deep Submergence Vehicle 1
DSV 1 is a bathyscaph: a deep-diving vessel that consists of a large gasoline-filled float and a pressure sphere for the crew. This vessel is used for oceanographic research, deep ocean geological studies, and deep ocean search, investigation, and recovery. DSV 1 made it deepest dive—to a depth of 20,236 feet—in 1977 in the Cayman Trough south of Cuba. It carries a crew of three.
According to the Museum:
“DSV 1 dives and rises by controlling its weight. DSV 1 carried 66,000 gallons for positive buoyancy and tons of iron shot the size of a BB for ballast. To dive, the crew vented the ballast tanks in the ends of the vessel allowing them to fill with seawater. This made the vessel negatively buoyant and it descended.
To return to the surface, the crew released the iron shot, making the vessel positively buoyant. The lift provided by the tank of aviation gasoline brought it to the surface.”
Why aviation gasoline? It is lighter than water and almost incompressible.
A typical dive lasted from 5 to 15 hours.
More museum exhibits
Naval Undersea Museum: Diversity and change in U.S. Navy submarines (museum tour)
Naval Undersea Museum: Working Underwater (photo diary)
Naval Undersea Museum: Mines (photo diary)
Naval Destroyer Museum: On the deck of the Turner Joy (photo diary)
Naval Destroyer Museum: Guns and torpedoes on the Turner Joy(photo diary)
Museums 101: Commercial Fishing (Photo Diary)
Museums 101: Japanese glass fishing floats (photo diary)
Museums 101: American glass fishing floats (photo diary)