Race to the bottom of the ocean

For the first time in over 50 years a manned sub has reached the deepest place in the ocean: the Mariana Trench, which plunges 11km (7 miles) down. Four teams had been vying to make the epic journey, but Avatar director James Cameron's Deepsea Challenger has become the first to hit the bottom. To read more about each team and their unique approach, click on the images below.