In the 1960s Rolex had a particular relationship with the top commercial diving company of the moment, COMEX (Compagnie Maritime d'Expertises), and it had been COMEX that asked Rolex to create a super diving watch capable of accomplishing the flames the commercial divers needed to reach. Rolex fulfilled the petition and produced a batch of special watches for the divers that would be the pre-curser of the Sea-Dweller collection for the general public.
The specially made watches for COMEX were actually the Rolex Submariner ref. 5513 diving timepieces customized with the Rolex patented Helium Escape Valve -- a groundbreaking mechanism that enabled the built-up gases to be released from the watch during decompression to keep it from bursting from too much pressure. The achievement of the modified orologi da sub vintage resulted in the 1967 launch of this new collection and reference, the Sea-Dweller ref. 1665 . It is these two lines of red writing which gave the piece its own nickname, the Double Red Sea-Dweller, or DRSD for short. As clearly indicated on the dial, the new Sea-Dweller could safely reach the incredible depth of 2000 feet, which makes it the choice opinion for deep-sea explorers.
Guides to purchasing pre-owned Rolex orologi cronografo uomo dictate to prevent these timepieces with engravings on the caseback. Why? Because that is normally an indication of a counterfeit product since the manufacturer doesn't generally engrave the casebacks of the watches. However, the Dual Red Sea-Dweller is the exception to this rule. Since Rolex typically does not engrave messages on the trunk, this view becomes even more precious.
About the casebacks of the DRSD are many engravings -- the Rolex emblem,"Gas Escape Valve","Rolex Patent" (on ancient versions of the watch it was written as"Patent Pending") and"Oyster". Some versions have the Rolex emblem etched across the casebacks, while some rarer models have the logo wrapped around the circumference.
The Rolex Dual Red Sea-Dweller was produced for a decade from 1967 until 1977 and throughout that time, many dials were made and are known by collectors as Mark I, Mark II, Mark III and Mark IV with their rarity ranking in descending sequence. But of course, all are coveted collectibles.
Diving into the background of this Double Red Sea-Dweller highlights an essential part of the heritage and underlines its loyal commitment to producing watches that are exceptional by challenging the status quo.