Don Walsh ( born November 2 , 1931 ) and Jacques Piccard are the first and only two persons till date to reach the deepest point of world 's Oceans in Mariana Trench on 23 January 1960 aboard the Bathyscaphe Trieste . Don Walsh ( born 2 November 1931 ) is an American oceanographer , explorer and marine policy specialist . He and Jacques Piccard were aboard the bathyscaphe Trieste when it made a record maximum descent into the Mariana Trench on 23 January 1960 , the deepest point of the world 's ocean .