The CURV (Cable-controlled Undersea Remote Vehicle) was a pioneering underwater drone developed by the Naval Undersea Warfare Center in San Diego (some sources say Pasadena, California) in the early 1960s. It was initially designed to recover test ordnance such as torpedoes lost off San Clemente Island at depths as great as 2,000 feet (610 m). CURV was the pioneer for teleoperation. CURV was also a prototype for remotely operated underwater vehicles and a pioneer for teleoperation. It became famous in 1966 when CURV-I was used to recover a hydrogen bomb from the floor of the Mediterranean Sea. In 1973, CURV-III performed the deepest underwater rescue in history when it rescued two men 1,575 feet (480 m) from the ocean surface who were stranded 76 hours in the submersible Pisces III with just minutes of air remaining. The CURV-III became known in the Great Lakes region in 1976 when it was used to survey the wreck of the SS Edmund Fitzgerald. CURV-21 is the current generation that replaced CURV-III and was recently used to photograph the wreck of the sunken El Faro, a merchant ship that disappeared in a hurricane in 2015.