Who made the first solo descent to Challenger Deep?

James Cameron made the first solo descent to Challenger Deep.

On March 26, 2012, the Canadian filmmaker and explorer piloted the one-person submersible Deepsea Challenger to the bottom of Challenger Deep, the deepest known area of the ocean floor. The dive took place in the Mariana Trench, in the western Pacific Ocean, and reached a recorded depth of about 10,908 metres.

Cameron’s descent came 52 years after the first successful visit to Challenger Deep. In 1960, Jacques Piccard and U.S. Navy lieutenant Don Walsh reached the bottom together in the bathyscaphe Trieste. Their achievement made them the first humans to reach the site, but neither made a solo descent.

Cameron had planned to spend several hours on the seafloor, documenting and sampling the environment. A hydraulic-fluid leak obscured the submersible’s viewing port and damaged its thrusters, so he began ascending after roughly two and a half hours at the bottom. Victor Vescovo later made repeated descents, but he was not the first solo visitor.