DSV-4 (ex-Sea Cliff) is a 25-ton, manned deep-ocean research submersible owned by the United States Navy. It is sister to DSV Turtle (DSV-3), DSV Alvin (DSV-2), and also an Alvin class Deep Submergence Vehicle. The Sea Cliff was retired from active service in 1998. Per the Naval Vessel Register, DSV-4 was returned to active service on September 30, 2002. It is known only by its hull number, not by name.
The DSV-4 originally had a maximum dive depth of 6500 feet (2000 m), like all Alvin-class DSVs at first. It was redesigned to dive to 20,000 feet, and refitted in 1984. With the refit of DSV-4 (ex-Trieste II, DSV-1) was retired from service. It has a plug hatch 24 inches in diameter, held in place mechanically with hatch dogs, and while submerged, by the pressure of the water above it. The Alvin-class DSVs were designed to replace older DSVs, such as the less maneuverable Trieste-class bathyscaphes. The DSV-4 can dive 5,000 feet deeper than the famed Alvin; however, the super Alvin class replacement for DSV-2 is designed to dive to 22,000 feet.
Famous quotes containing the words sea and/or cliff:
“In the midst of this chopping sea of civilized life, such are the clouds and storms and quicksands and thousand-and-one items to be allowed for, that a man has to live, if he would not founder and go to the bottom and not make his port at all, by dead reckoning, and he must be a great calculator indeed who succeeds.”
—Henry David Thoreau (1817–1862)
“You could not tell, and yet it looked as if
The shore was lucky in being backed by cliff,
The cliff in being backed by continent;
It looked as if a night of dark intent
Was coming, and not only a night, an age.”
—Robert Frost (1874–1963)