Canadian film director James Cameron is gathering a team of engineers to build a submersible that can visit the Pacific’s Mariana Trench, the ocean’s deepest point, to gather footage for the sequel to his blockbuster 2009 movie Avatar. Only one other team has ever visited the Mariana Trench: Captain Don Walsh, a US Navy submariner, and Jacques Piccard, a Swiss engineer, who descended for five hours in a steel submersible called the Trieste in January 1960. No one has ever tried to repreat the descent, until now. Cameron’s vessel is reportedly being assembled in Australia and tests on the hull are already completed; a trial dive might occur later this year. Cameron’s engineers are studying the Trieste’s descent, in which—less than an hour into it, at a depth of 4,200 feet—a dribble of water appeared on the wall. Another leak was sprung at 18,000 feet, which sealed itself again, and at 32,400 feet (deeper than Mount Everest is high) there was a crack and the vessel’s cabin shook. But they made it.