In rough Pacific sea on 23 January 1960, United States Navy Lieutenant Don Walsh and Swiss engineer and oceanographer Jacques Piccard lowered themselves through the narrow opening into the cabin of the bathyscaphe, Trieste. Walsh piloted the Trieste toward the absolute darkness of Challenger Deep. At 10,924 metres, the pressure is roughly eight tons per square inch. The trench was believed to contain only skeletons, yet with the aid of Trieste’s lamps, Walsh and Piccard witnessed marine life. The Trieste had become the first vessel to reach the deepest part of the Earth’s ocean. The record set 50 years ago remains the only manned mission to reach the deepest part of the Earth’s ocean.