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A New Type of Dive Watch: The Rolex Sea-Dweller, Reference 1665

August 14, 2019

BY Paul Altieri


As the company that invented the world’s first waterproof watch, Rolex has always been a leader in building watches that can survive in aquatic conditions. However, during the late 1960’s, deep-sea experiments called for a different kind of watch – one that could withstand the extreme pressures of saturation diving. From this initial need, Rolex reinvented the dive watch and created the first Rolex Sea-Dweller.

Rolex Double Red Sea-Dweller 1665

The “Double Red” Rolex Sea-Dweller 1665 was the very first version that was released to the public.

Rolex and COMEX

The French deep-sea diving company, COMEX was among the first to experiment with saturation diving – a method of diving in which helium replaces nitrogen in the air, allowing divers to work at much greater depths and for extended periods of time without the need to resurface. The numerous hours (or days) spent in pressurized chambers would force helium molecules inside the divers’ watches, and during decompression, the trapped helium would expand, causing the crystals to pop clean off their watches.

Rolex Sea-Dweller 1665 predates COMEX Submariner 16800

COMEX was among the first to experiment with saturation diving.

The solution to Rolex’s pressurization problem came in the form of a helium gas escape valve on the Sea-Dweller. These valves allowed trapped helium molecules to exit freely, without generating pressure inside the watch. The first ever helium escape valves appeared on standard reference 5513 Submariners that were prototypes made specifically for COMEX. These Submariners received 5514 reference numbers, and were never released to the public.

Experimentation with these modified Submariners led Rolex to create the Sea-Dweller, tripling their previous depth rating. The first ever Rolex Sea-Dwellers were modified Submariners, and they did not feature helium gas escape valves. It is believed that 30 such watches were created, although few remain as many failed at some point or another during saturation dive testing.

Rolex DRSD Sea-Dweller 1665

The Rolex Sea-Dweller 1665 was the first production watch to feature a helium gas escape valve.

Rolex Sea-Dweller 1665

Two different versions of the reference 1665 Sea-Dweller were released – not including the 12 prototype “Single Red” Sea-Dweller (SRSD) watches that were used for testing purposes or given as awards to select individuals. When it first made its debut, the Sea-Dweller 1665 received a dial that had the words “SEA-DWELLER” and “SUBMARINER 2000” printed in red ink (hence their “Double Red” Sea-Dweller or “DRSD” nickname), while later examples of the reference 1665 adopted dials with all-white text, and abandoned the “SUBMARINER 2000” branding entirely, leading to their “Great White” nickname.

Rolex Great White Sea-Dweller 1665

Later versions of the Rolex Sea-Dweller 1665 received dials with all-white text.

Additionally, when the very first batch of Sea-Dweller watches were made, Rolex had filed for, but had not yet received the patent for the helium escape valve. Consequently, these early Sea-Dweller watches have the words, ‘ROLEX OYSTER GAS ESCAPE VALVE (PATENT PENDING)’ engraved on their casebacks, which was later replaced by “ROLEX PATENT OYSTER GAS ESCAPE VALVE” on all later versions of the reference 1665. Since only a handful of these early “Patent Pending” Sea-Dweller watches were ever produced and they represent the very start of the Sea-Dweller collection, they are now incredibly valuable and highly sough-after by collectors.

The reference 1665 Sea-Dweller is significant to Rolex’s history because it represents the brand’s ongoing pledge to produce high-quality timepieces that excel in extreme conditions. As soon as advances in diving technology created the need for a new kind of dive watch, Rolex was there to fill that need with a watch that surpassed every necessary specification. While the practical use of mechanical watches has been all but eliminated from modern scuba diving – let alone are professional saturation divers still relying on mechanical timepieces – the Rolex Sea-Dweller remains a mainstay the brand’s catalog, and Rolex even released a luxurious two-tone version in stainless steel and 18k gold earlier this year at Baselworld 2019.

Rolex Sea-Dweller 126600

The reference 126600 is the most recent version of the stainless steel Rolex Sea-Dweller.



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