bathyscaphe

A bathyscaphe is a self-propelled submersible used in deep-sea dives.

The US Navy had acquired a submersible called the bathyscaphe Trieste and Don, a submarine lieutenant, volunteered to join the project.

The bathyscaphe had been built to withstand more than 1,000 times the pressure at sea level, but it had never been tested to its limits at these kinds of depths until now.

On 23 January, 1960, Don and Swiss oceanographer Jacques Piccard, who had designed the bathyscaphe with his father Auguste Piccard, began their descent beneath the waves.

The start of the dive went smoothly, but at around 9,000m, the bathyscaphe jolted with an alarming bang.