His depth on arrival: 35,756 feet (10,898 meters)—a figure unattainable anywhere else in the ocean.
Folded into a sub cockpit as cramped as any Apollo capsule, the National Geographic explorer and frilmmaker is now investigating a seascape more alien to humans than the moon. Cameron is only the third person to reach this Pacific Ocean valley southwest of Guam (map)—and the only one to do so solo.