Year: Circa 1978
Reference No: 1665
Movement No: D867’124
Case No: 5’721’508, repeated inside caseback 1665
Model Name: Sea-Dweller, “Rail Dial”
Material: Stainless steel
Calibre: Automatic, cal. 1570, 26 jewels
Bracelet/Strap: Stainless steel Rolex Oyster bracelet stamped “93150”, endlink stamped “585”, max length 185mm
Clasp/Buckle: Stainless steel Rolex Oyster deployant clasp stamped “VD”
Accessories: Accompanied by Rolex instruction manual, product literature, hang tag, cloth, two green passport holders, note pad, cloth, outer packaging and fitted presentation box.

First introduced to the public in 1967, the Sea-Dweller ref. 1665 features a helium escape valve to release pressure during expeditions of deeper depths. While first examples of the Sea-Dweller ref. 1665 featured two lines of red text at 6 o’clock, later examples featured white texts throughout, hence earning its nickname the “Great White”. It was the very first time the Sea-Dweller was modeled as a separate line instead of an extension from the Submariner ref. 5513. Further enhanced by its rarity, the present example is what collectors known as the MK II rail dial variant of the reference. With production for only two years between 1977 to 1979 with a serial number between 5.7 million to 6.2 million, the dials were made by the Stern Company instead of Singer. Elusive and highly collectible, the Rail dial can be distinguished by the subtle details. The “C” of chronometer lines up with the “C” of Certified creating an unusual yet pleasing vertical corridor or rail between the last two lines of the designation is what gives the dial its nickname. It’s worth noting that the MK II variant is also the only Sea-Dweller that bears a “T SWISS T <25” amongst all variants. The present example Rolex Sea-Dweller ref. 1665 MKII “Rail Dial” from circa 1978 with a 5.7 million serial is a great example featuring an attractive dial with consistently aged luminous material that has developed a warm mustard hue.