Robert Croft is a free-diver who, in 1967, became the first person to free-dive beyond the depth of 200 feet. Croft was a US Navy diving instructor in 1962 at the US Naval Submarine Base New London submarine school in Groton, Connecticut. At the submarine escape training tank, instructors train prospective submariners how to escape from a disabled submarine, which could be resting on the sea bottom.