thumb|Arrival of the DSRV Avalon at [[Brest, France|Brest airport aboard a Lockheed C-5 Galaxy strategic airlifter]]
Mystic class is a class of deep-submergence rescue vehicles (DSRVs), designed for rescue operations on submerged, disabled submarines of the United States Navy or foreign navies. The two submarines of the class were never used for this purpose, and were replaced by the Submarine Rescue Diving Recompression System.
Features
DSRVs are designed for quick deployment in the event of a submarine accident. DSRVs are transportable by truck, aircraft, ship, or by specially configured attack submarine. At the accident site, the DSRV works with either a "mother ship" or "mother submarine". The DSRV dives, conducts a sonar search, and attaches to the disabled submarine's hatch. DSRVs can embark up to 24 persons for transfer to the mother vessel.
The DSRV also has an arm to clear hatches on a disabled submarine and a combined gripper and cable cutter. The gripper is able to lift 1,000 pounds (450 kg).
Background
thumb|300px|The U.S. Navy's Mystic secured to a [[Los Angeles-class submarine|Los Angeles class attack submarine]]
The Deep Submergence System Project was established in June 1965 in the aftermath of the loss of USS Thresher in 1963.
At the time, submarine operating depths greatly exceeded the capabilities of rescue vessels. Lockheed Missiles and Space Company was contracted to produce a deep diving rescue submarine. In an effort to win the design and construction contracts for a DSRV, the company built Deep Quest prototype. She was launched in June 1967; in March 1970, she was used to find a US Navy Grumman F6F-3 Hellcat which had crashed on 12 January 1944, in the ocean near Naval Air Station San Diego.
The first DSRV was launched in 1970. While it has been alleged that the stated goal of the DSRV project was unrealistic, and that it was a front for research on undersea espionage, including cable tapping,