Jacques Piccard (28 July 1922 -- 1 November 2008) was a Swiss oceanographer and engineer, known for having developed underwater vehicles for studying ocean currents. In the Challenger Deep, he and Lt. Don Walsh of the United States Navy were the first people to explore the deepest part of the world 's ocean, and the deepest location on the surface of Earth 's crust, the Mariana Trench, located in the western North Pacific Ocean.
who was the first man to reach the deepest part of the ocean
Jacques Piccard Don Walsh