Answer

In March 2012, filmmaker James Cameron piloted the Deepsea Challenger to the bottom of the Mariana Trench, reaching approximately 10,908 meters. This made him the first person to make the journey solo and only the third person ever to reach Challenger Deep. The other submersibles listed — Alvin, Nautile, and Shinkai 6500 — are all real deep-sea research vessels but none has reached full ocean depth.