James Cameron Trench Dive

James Cameron has made a record-breaking solo dive to the bottom of the Mariana Trench, the deepest part of any ocean on our planet.

The trench, which is located 11 kilometres (seven miles) beneath the surface of the Pacific Ocean, had not been reached for over 50 years, with the only other successful manned visit undertaken by the now legendry Bathyscaphe Trieste submersible In January 1960 by Jacques Piccard and Don Walsh.

The Trieste has long since been retired however, with the new descent undertaken within a purpose-built submarine, the Deepsea Challenger. Cameron designed this one-man sub himself and, after a series of test dives, It has now taken the Hollywood director right down to the base of the underwater canyon.

Speaking to the BBC on the tropical island of Guam – which was the base of operations for the mission – Cameron explained what led him to build the sub in the first place: “I started to think about what It would take to go to full ocean depth – that was kind of the Holy Grail from an engineering standpoint.

So [I started working] up designs, and thinking how it would be possible and what it would take. And then there is suddenly this moment that seems to transpire with no transition where you are suddenly doing it. I seem to have that curse that once I imagine something being built, I have to build It.”

During the dive, Cameron was contained within a 109-centimetre (43-inch)-diameter steel sphere, from where he was able to control all aspects of the submarine. The sphere had to be so small for both weight and strength reasons, needing to be light enough to be easily lifted back to the surface, but also strong enough to withstand over 1,000 atmospheres of pressure (1,000 kilograms per square centimeter / 14,700 pounds per square Inch).

The director – who has helmed blockbuster feature films centred on marine disasters such as Titanic and The Abyss – hoped to capture the Mariana Trench like never before, recording footage on the submarine’s cutting-edge RED Epic 5K video camera. However, despite spending over 20 minutes on the floor of the Mariana Trench and three hours within it, little Imagery and video was able to be taken, as the Challenger’s landing caused large quantities of silt to be kicked up, obscuring the camera’s view.

Speaking on Cameron’s successful return to the surface, Dr Alan Jamieson of Oceanlab, told the BBC: “I think what James Cameron has done is a really good achievement in terms of human endeavour and technology. But my feeling is that manned submersibles like this are limited in scientific capabilities when compared to other systems, mostly due to the fact there is someone in it. Remote or autonomous systems can collect a far greater volume of useful scientific data for far less money.”

Facts about Deepsea Challenger

Batteries – The Challenger is fitted with a stack of 70 loaf-sized battery packs within oil-filled plastic boxes mounted to its side. These are split across three power buses.

Light array – As well as the spotlight, additional light sources come from a 2m (6.6ft) panel of LED lights. These can illuminate a 30m (100ft) area.

Booms – Two booms hold both the sub’s RED Epic 5K video camera as well as a primary spotlight. These can be controlled manually by the pilot.

Weights – More than 450kg (1,000lb) of steel weights are equipped to the Challenger so it can descend quickly; they are held in place by electromagnets.

Pilot sphere – A 6.4cm (2.5in)-thick steel sphere where the Challenger’s pilot sits. It is spherical so that it can withstand the intense pressures of the deep ocean.