where have only 2 people (walsh and piccard) been on earth?

Jacques Piccard (born July 28, 1922) is a Belgian explorer and engineer, known for having developed underwater vehicles for studying ocean currents. He is the only person (as of 2006), along with Lt. Don Walsh, to have reached the deepest point on the earth's surface, the Challenger Deep, in the Mariana Trench. On January 23, 1960, Jacques Piccard and Don Walsh, reached the ocean floor in the Challenger Deep with his bathyscaphe Trieste. The depth of the descent was measured at 10,916 meters (35,813 feet), later more accurate measurements in 1995 have found the Challenger Deep to be less deep at 10,911 m (35,797 ft). The descent took almost five hours and the two men spent barely twenty minutes on the ocean floor before undertaking the 3 hour 15 minute ascent.