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Marianas Trench, Greatest Ocean Depth

MarianasOn January 23, 1960, US Navy lieutenant Don Walsh and Swiss engineer Jacques Piccard set a record for the deepest descent below the ocean’s surface. Their submarine, a 150-ton steel bathyscaph called Trieste, had been designed by Piccard’s father, Auguste—another member of the Club. Now Auguste’s machine would face the ultimate test, with his son inside.

Marianas2Walsh and Piccard descended at a fast clip, four feet per second, but their vertical voyage still took five hours to complete, so great was the depth. The seabed of the Marianas Trench, in the Pacific Ocean off the island of Guam, lies more than 36,000 feet below the waves—roughly the same distance below sea level as the cruising altitude of a commercial airliner above sea level. The Trieste ultimately reached a record-setting depth of 35,800 feet.

Marianas3The expedition, sponsored by the US Navy, found that sea life can exist at these amazing depths, where the pressure is eight tons per square inch: Out the window of the bathyscaph, Piccard observed what was later determined to be a sea cucumber, a marine animal related to the starfish and the sea urchin. The expedition also proved that other life can survive the depths: Two intrepid explorers named Walsh and Piccard.

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Background image photography courtesy of members Christoph Baumer, Neil Laughton, Matt Harris and Don Walsh's image of the Bathyscape Trieste