<P> 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 . </P>
who was the first man to reach the deepest part of the ocean
Jacques Piccard Don Walsh