DSRV-2 Avalon was a Mystic-class deep-submergence rescue vehicle rated to dive up to 5000 feet (1500 m) to rescue submarine crews trapped deep under the sea.
The submarine was acquired in response to the loss of the USS Thresher, so that the Navy would have a way to rescue trapped submarine crews.

Avalon was launched in 1971.
 The submarine, intended to be air transportable, is 50 feet (15 m) long, 8 feet (2.4 m) in diameter, and weighs 37 tons.
 The sub is capable of descending to 5,000 feet (1,500 m) below the surface and could carry 24 passengers at a time in addition to her crew.
Avalon is battery-powered, and would have needed to pause midway through a rescue mission to recharge its batteries.

Avalon was stationed at North Island Naval Station in San Diego and was never required to conduct an actual rescue operation.
The sub was decommissioned in 2000.
 The Avalon submarine was donated to the Morro Bay Maritime Museum in Morro Bay, California, and is currently on public display.
DSRV-2 Avalon was a Mystic-class deep-submergence rescue vehicle rated to dive up to 5000 feet (1500 m) to rescue submarine crews trapped deep under the sea. The submarine was acquired in response to the loss of the USS Thresher, so that the Navy would have a way to rescue trapped submarine crews.
Avalon was launched in 1971.  The submarine, intended to be air transportable, is 50 feet (15 m) long, 8 feet (2.4 m) in diameter, and weighs 37 tons.  The sub is capable of descending to 5,000 feet (1,500 m) below the surface and could carry 24 passengers at a time in addition to her crew. Avalon is battery-powered, and would have needed to pause midway through a rescue mission to recharge its batteries.
Avalon was stationed at North Island Naval Station in San Diego and was never required to conduct an actual rescue operation. The sub was decommissioned in 2000.  The Avalon submarine was donated to the Morro Bay Maritime Museum in Morro Bay, California, and is currently on public display.
DSRV-2 Avalon