1975 Rolex Double Red Sea-Dweller (Ref. 1665) Mk. III "Pumpkin"

Rolex Seadweller Comex ad

(Co-Branded DRSD Comex/Rolex AD c. 1970's)

In the early part of the 1960s deep-sea diving and in particular, mixed gas diving was advancing. The Submariner became the quintessential diver born out of the late 1950s, with its iconic design which set the standard for almost all dive watches to come thereafter its launch in 1953. The Rolex SeaDweller was born in the 1960s out of the collaboration with COMEX a French deep-sea diving company. Comex is sometimes referred to as the NASA of the deep seas and was the pioneer in mixed gas diving.

In typical Rolex fashion meaning form following function, most of the SeaDwellers design was born out of the need to comply with the commercial ISO 6425 diving standard, which defines test standards and features for watches suitable for diving with underwater breathing apparatus in depths of 100 m (330 ft) or more. 

Saturation diving requires the use of helium in the breathing gas mixture, and helium particles would accumulate within the case of a diving watch during prolonged exposure meaning long deep dives and or at depths greater than 200 meters/660 feet where mixed bringing gas was essential. During the early days of deep saturation diving, a strange phenomenon was arising during the decompression of these dives in which the pressure inside the watch would build as a result of helium gas being trapped in the cases of the watches that were being used. The weakest point of the watch at the time was the crystal and upon decompression from the dives, the helium gas would expand, ejecting the plexiglass crystal as that helium gas forced its way outward. Being that watches back then were crucial tools for timing decompression and other important events this was a major flaw that needed to be fixed. Rolex developed a rather simple and practical mechanism to solve this issue by developing a helium escape valve on the side of the case that allowed the helium particles to escape while still maintaining an ISO 6425 diving standard and water resistance rating.

Founder Of COMEX, Henri Delauze [1970](Founder Of COMEX, Henri Delauze c. 1970)


The new model of Submariner was created was dubbed the reference 1665, based on the existing Submariner model with some major upgrades. Initial prototype models were exclusively issued to DeepSea Explorers of the 1960s in various configurations but in the late 1960 and early 1970s, the model made it to the Rolex retail stores.  The Double Red Sea-Dweller (DRSD) was produced for approximately 10 yrs starting from 1967 to 1977 with serial numbers ranging from 1.7 to 5.1 million. There were four different dial variations made in the regular production model with three different case back configurations. Post 5.1 million serial number ref. 1665 Sea-Dwellers can be seen only bearing white text and have earned the nickname, "great white" Sea-Dweller.

The Sea-Dweller is undoubtedly the most advanced amongst the diving watches of its time. Featuring a bidirectional bezel, a tropic super domed bezel to withstand greater pressure, and date complication. Fully certified and guaranteed waterproof to 2000ft - 610m. 

Stock # RLXDRSD1665III
Brand Rolex
Style Sea-Dweller
Model 1665
Serial 406XXXX
Size Men's
Material SS
Dial Black Matte Mk. III
Millimeters 40
Bracelet Rolex Oyster 93150 Flip Lock 585 End Pieces



The excellent case has been lightly polished in the past, retaining very thick and even lugs. The Mk. III "fat-font" bezel insert has faded to a wonderful blue/grey coloration and shows light signs of use, the pearl is missing from the 12 o'clock position. The watch retains its original T-39 "Superdome" crystal. The inside of the case back features the same serial number as the mid-case, and the serial and reference numbers are visible between the lugs. The Rolex 93150 Oyster bracelet retains its correct 585 end pieces and is stamped 1/76, and retains 11 links including its "PATENTED" divers extension. 


This Mk. III Double Red Sea-Dweller dial is in immaculate factory condition, showing absolutely no blemishing or chipping to the dial. The dial displays the correct Mk. III font alignment and the open 6 in 610M depth rating. The tritium markers have aged to a vibrant orange or "pumpkin" patina and display the correct "band-aid" like texture, showing no degradation under U.V. light inspection. The tritium hands match the dial perfectly, under U.V. light inspection the hour hand shows some minor cracking but remains stable the minute and sweep-seconds hand remains fully intact. The silver date wheel is era correct displaying open 6's and 9's.


None. The watch is keeping time at COSC spec and comes backed by a 1-year warranty on accurate timekeeping.

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