Rolex Deepsea D-Blue (ref. 116660) was released two years ago. It is commemorate James Cameron’s record setting journey to the deepest point on Earth in 2012.
Like all modern Rolex watches, the Deepsea is a beautifully manufactured product, neither artisanal nor handmade, but the result of the efforts of numerous clever engineers and watchmakers who will forever remain anonymous. Its key feature is ingeniously simple but remarkably effective: the Ringlock System, constructed to withstand enormous pressure but without the case needing to be quite as big as it would be without the patented invention. 
The Deepsea is rated to 12,800 ft or 3900 m, three times as deep as Rolex’s classic saturation diver’s watch, the Sea-Dweller 4000, and much deeper than even a nuclear submarine can reach. While its prowess is entirely academic, the ingenious construction of the watch is tangible. Though the Deepsea is a large watch, it is actually smaller than it would be without the Ringlock System. The Deepsea is just under 17.7 mm high, but achieving the same depth rating with conventional construction would require a case 19.7 mm thick according to Rolex’s experiments.
Essentially a stainless steel inner ring inside the case, on which the crystal is mounted on the front, and a titanium case back on the rear, the Ringlock System is the subject of a 12 page long patent we explain here in distilled form.
