Diving Legacy The Rolex Sea-Dweller was developed in the 1960s as a professional-grade diving watch, engineered to withstand the crushing pressures of deep-sea exploration. With its helium escape valve and robust construction, it became a trusted companion for saturation divers and underwater pioneers alike. Engineered for Depth This reference 16600, from 2004, features a 40mm Oystersteel case with a unidirectional rotatable bezel and black 60-minute insert. Powered by the calibre 3135 automatic movement, it offers a 48-hour power reserve and is fitted with a Fliplock Oysterlock clasp for added security. A tool watch built for the oceans extremes.