The Mariana Trench is perhaps the most isolated place on the planet. Film director James Cameron recently took a real-life expedition to Earth’s ocean floor Cameron describes his journey during an in-depth interview to promote his National Geographic special, airing April 29th: “I was watching the numbers going deeper. The sub slows down as you get to the target depth. There is a long moment of getting to think about it. Then you have to get busy. You have less than a thousand feet from the bottom, you fine-tune the ballast, adjust the camera, turn up the spotlight. As the altimeter counted, I saw the glow of the bottom!” 

He went 6.8 miles down to the spot known as the Challenger Deep in the Pacific Ocean’s Mariana Trench, an area deeper than Mt. Everest is tall. The record-breaking trip that made headlines around the world was part of DEEPSEA CHALLENGE, a joint scientific expedition by Cameron, National Geographic and Rolex to conduct deep-ocean research and exploration. Cameron is the only individual ever to complete the dive in a solo vehicle and the first person since 1960 to reach the very bottom of the world in a manned submersible.

You can watch April 29, at 9 p.m. and 9:30 p.m. ET/PT, with an encore Thursday, May 3, at 9 p.m. and 9:30 p.m. ET/PT.