Two weeks after the new no-date Submariner was presented at Baselworld 2012, Rolex announced the Deepsea Challenge made for filmmaker James Cameron’s Deepsea Challenger Expedition. Scheduled to take plan less than a week from now, the Deepsea Challenger expedition will see Cameron pilot a custom-designed submersible to Challenger Deep in the Mariana Trench, the deepest place on Earth at 35,800 ft or 10,912 m.

Built to withstand the awesome pressures at such depths – the watch will be strapped to a robot arm on the hull of the submersible – the Deepsea Challenge is a bulked-up Sea-Dweller Deepsea, with a depth rating of 39,370 ft or 12,000 m. A feat of engineering too large to wear, the Deepsea Challenge measures 51.4 mm wide, essentially the same size as a tin can. And it is 28.5 mm high – the height as four ordinary watches stacked up – with the sapphire crystal alone some 14.3 mm. That gives it a load resistance of 13.6 tonnes, equivalent to six sport utility vehicles.

The watch is constructed like that of the Sea-Dweller Deepsea, with the patented Ringlock system that’s centred around a nitrogen-alloyed steel ring inside the case. The crystal sides on the top of the steel ring, while a flexible titanium back covers the back. As the watch descends into the ocean, the pressure exerted forces the crystal and back against the ring, tightening the seals and ensuring nothing enters the case.

The Deep Sea Special, c. 1960

The Deepsea Challenger expedition is happening fifty two years after Rolex made a small number of Deep Sea Special watches, rated to 35,789 ft or 10,908 m, for Jacques Piccard’s  Trieste bathyscaph expedition that was the first to visit Challenger Deep.