Pisces III Deepest Sub Rescue
In August 1973, Englishmen Roger Chapman and Roger Mallinson were trapped 1,575 feet below the surface in the Celtic Sea when their Pisces III submersible sank after a buoyancy tank inadvertently flooded during cable-laying work off Ireland. For 76 hours they sat cold and wet inside the cramped pressure sphere, rationing a single sandwich and a can of lemonade and speaking as little as possible to stretch their 72 hours of life support.
An international team from Britain, Canada, and the United States used sister submersibles Pisces II and Pisces V along with the US Navy's CURV-III remotely operated vehicle to attach lift lines and haul the crippled craft toward the surface. When divers finally opened the hatch after more than three days, both men were alive with only about 12 minutes of breathable air remaining, in what remains the deepest successful underwater rescue ever carried out.