Jacques Piccard

Jacques Piccard was a Swiss oceanographer and engineer, known for having developed submarines for studying ocean currents. In the Challenger Deep, on 23 January 1960 he and Lieutenant Don Walsh of the United States Navy were the first people to explore the deepest known part of the world's ocean, and the deepest known location on the surface of Earth's crust, the Mariana Trench, located in the western North Pacific Ocean.