What is "curv-iii"

CURV-III was the fourth generation of the United States Navy Cable-controlled Undersea Recovery Vehicle (CURV). CURV was 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 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.