Model: Great White Sea Dweller Reference: 1665 Date: Circa 1979 Movement: 26-jewel Cal.1570 automatic, free-sprung Glucydor balance, adjusted to 5 positions & temperature, No.D784602 Dial: Matte black, luminous dot hour markers, baton quarters, white outer minute divisions, date aperture at 3, polished Mercedes hands with luminous inserts, centre seconds Case: Brushed and polished tonneau form, screw down back and shouldered crown, helium escape valve at 9, calibrated bi-directional bezel, No.6014669 Strap/Bracelet: Brushed 93750 Oyster link, end links stamped 585 Buckle/Clasp: Signed folding clasp, stamped VC Signed: Case, dial & movement Size: 38mm Accompaniments: Rolex box, outer card, undated punched Guarantee, brochures, swing tags, anchor 注脚 The Rolex Sea-Dweller was first launched in the 1960's having been specially developed for deep-sea divers. Saturation divers who had previously been issued with Rolex Submariners found that during decompression, the pressure inside the watch would force its way out through the weakest point which usually resulted in the loss of the plexiglass. In response to this, Rolex developed the Sea-Dweller. With a helium escape valve on the side, a greater depth rating of 610 meters and the removal of the cyclops from the crystal, the Sea-Dweller is a true tool watch and has been favoured by professional divers ever since its introduction. This particular version of the reference 1665 succeeded the Double Red Sea-Dweller in 1977. The most noticeable difference was that the red text on the dial was replaced with white text, earning the watch the nickname of 'Great White' amongst collectors. The current example is even more unusual in that it is fitted with a rare rail dial. The rail dial was produced for only two years, between 1977 and 1979, and is so called because of how the 'C' in both 'Chronometer' and 'Certified' line up almost perfectly, reminiscent of the parallel lines of a train track.