The iconic Rolex Oyster watch, launched in 1926 and inspired by the hermetic seal of an oyster shell, was the world's first patented watertight wristwatch. Instantly recognisable, the Oyster has evolved over the decades to become a professional divers' watch engineered for extreme depths. The latest member of Rolex's professional dive watches is the Deepsea D-Blue, which was designed to celebrate film director James Cameron's descent to the last great frontier of the world, the Mariana Trench, 11,000m under the sea. The rugged 44mm stainless steel case is reinforced by Rolex's patented Ringlock system. The evocative blue dial reflects the changing hues of the ocean, graduating from a brilliant azure blue to a dark, midnight blue to represent the abyss into which Cameron descended. The dial features a Chromalight display allowing the indices, hands and zero marker on the bezel to glow with a blue light for twice as long as standard luminescent materials. Equipped with Rolex's patented helium escape valve, the Deepsea D-Blue is able to withstand pressure at depths of up to 3,900m. The COSC chronometer-certified Deepsea Dive D Blue diver watch is powered by Rolex's calibre 3135 mechanical self-winding movement and is presented on an Oyster link bracelet.