Crew of the US Navy Trieste bathyscaphe sanding on top of the vehicle. From left to right are Lieutenant Larry Shumaker, Assistant Officer in Charge; Lieutenant Donald Walsh, Officer in Charge; Dr Andreas B Rechnitzer, Scientist in Charge; and Swiss physicist Jacques Piccard, co-designer and Technical Advisor. A bathyscaphe is a free-diving self-propelled deep-sea submersible that uses a pressurised cabin suspended below a float. The Trieste measured around 18 metres long. It was launched in 1953. On 23rd January 1960 it was used to descend to the deepest known part of the Earth's oceans, Challenger Deep in The Marianas Trench, with Walsh and Piccard on board. The record depth is around 10,900 metres below sea level. Photographed on 16th November 1959.