Discovering the deepest place on earth requires some incredible kit. In 2012, film direction James Cameron piloted a submarine to the bottom of the Mariana Trench - and today a film of his expedition Deepsea Challenge 3D is released in cinemas across the US.
The 7 mile descent in the submersible took two and a half hours. 'This might be the dumbest idea I have ever had,' Cameron says at one point during the descent.
Here are some incredible facts about the unique submersible used for the project:
1 The submersible spent 3 hours on the ocean floor
2 The pilot's cockpit (or sphere, as Cameron and his team called it) was just 109cm wide. The pilot had to keep his knees bent, and could barely move.
3 The pilot chamber is a sphere because it’s the strongest shape for resisting pressure—if the pilot sat in a cylinder, the walls would need to be three times thicker.
4 Water vapour from the pilot’s breath and sweat condenses on the cold metal sphere and drains to a space where it’s sucked into a plastic bag. In an emergency, the pilot can drink it. Nice.
5 More than 180 systems—from battery packs to sonar—operated during dives.
6 Every circuit board in the sub’s exterior electronics—more than 1,500 of them—was designed and built specially for it.
7 The sub is equipped with “cruise control” so the pilot can hover exactly where he wants to or glide through the water at a constant speed.
8 The submersible spins slowly as it descends and ascends. It’s engineered to do this so it doesn’t veer off track.
9 An experimental Rolex watch depth rated to 12,000m was attached to the arm of Cameron's submersible.
10 You can buy a Rolex Deepsea Sea-Dweller watch, launched to coincide with the release of the film, which is depth rated to 3,900m, in case you follow in Cameron's footsteps. It will set you back more than $12,000 though.