Rolex Rolex 1665 Great White Sea-dweller rail dial 1979

Rolex 1665 Great White Sea-dweller rail dial 1979

Brand: Rolex
Model: Sea Dweller
Reference: 1665
Gender: Uni-sex
Year: 1979
Material: stainless steel
Dial Color: black
Dimensions: 40 mm
Watch Movement: automatic
Bracelet/Strap: stainless steel
Box/Paper: only watch
Condition: Excellent

Rolex 1665 Great White Sea-dweller rail dial 1979


This is a rare opportunity to get yourself a rally nice and super cool Rolex 1665 Great White with a rare Mark II Rail dial. This watch comes with the full length bracelet with the correct year VD year code and divers extension.


Characteristics reference 1665

The Sea-Dweller is a Submariner on steroids! Launched in the late 1960s, it has been developed for the saturation divers of COMEX and was introduced to meet the needs of commercial divers to reach greater depths. The 1665 reference has been made from until 1967 until 1982. You can recognize a 1665 Sea-Dweller due to the following 2 main characteristics:

  • Superdome acrylic crystal without a cyclops. This model lacks a cyclops or date loupe— providing a cleaner and more simple look in comparison with its sibling the Submariner Date.
  • Then there is the signature feature that defines the Sea-Dweller – the Gas Escape Valve. The watch incorporates a helium release escape valve for gas decompression chambers

The reference 1665 has a couple of different executions. The first examples weren’t introduced for the general public but were prototypes and tested by professional divers. These examples were the Single Red Sea-Dwellers with a depth rating of 1650 ft/500 m. These were followed by the Double Red Sea-Dwellers which were commercially introduced in late 1968/beginning of 1969. The dials of the Great White had less text since the text SUBMARINER 2000  was removed.


Comex: Omega or Rolex?

First introduced in 1967, the Rolex Sea-Dweller has an illustrious history. It was created for the divers of deep sea diving specialist COMEX, and the first watch to have a helium escape valve. So the Sea-Dweller ref. 16600 was mourned when it was discontinued in the late 2008 and replaced by the very much larger Deepsea.


In the late sixties COMEX started pioneering a new method of diving called "Saturation Diving" which allowed divers to stay submerged for much greater lengths of time. Saturation diving is a diving technique that allows divers to reduce the risk of decompression sickness ("the bends") when they work at great depths for long periods of time. When divers dive into the great depths there is always

always a danger of decompression sickness which occurs when inert gas that had been absorbed by the body forms bubbles under the pressure of decompression. These bubbles can then block blood vessels or damage nearby cells. By having the divers breathe a mixture of helium, hydrogen and oxygen in their tanks and then having them breathe the same mixture in a pressurized underwater environment, the divers can last for days (or even weeks) underwater and only resurface once at the end of the dive, thus reducing the risk of the bends significantly. However, the human body is much more adept at disposing of helium than a watch case is. The divers found that helium molecules would pass through the seals of a watch and expand. Violently. Imagine a champagne cork but made of the crystal of a watch. Not what you want to be happening hundreds of meters underwater in a small capsule.


By the end of the decade COMEX aimed to send divers down to depths of 300 meters (1,000 ft+), 100 meters deeper than the highest rated Submariner or Seamaster could handle. This objective was the motivation for the Rolex Sea-Dweller and Omega Seamaster 600. Both brands took up the challenge to produce the best watch for saturation diving.


Omega designed a Omega decided to completely start afresh from anything they had made before and it took four years of development to produce the Ref. 166.077, the Omega Seamaster 600, in 1970. Their original plans had been to fashion a watch using titanium (10 prototypes had already been made) but titanium was very expensive to buy and very difficult to machine. Instead of titanium, Omega developed a solid stainless steel mono-block case; by forgoing the removable case back, the only two points of entry for water were the crown and the crystal. After chemical treatment to make it anti-reflective and anti-abrasive, a 4mm thick mineral crystal was tested at being able to withstand pressure of up to 60 atmospheres. If you look at the crown on the Seamaster 600 you could be forgiven for thinking that it is square, however this is just a shield that would stop the crown from unwinding accidentally under pressure. Due to the large crown guards and this extra cover, Omega decided to place the crown at the 9 o'clock position so divers could move their right hand free from obstruction. The name PloProf actually came from the French divers who used the Seamaster, Plongeur Professionel, Plo. Prof. Rather than the standard uni-directional bezel, the bezel on the Seamaster was bi-directional and was activated by pushing the orange button located on the side of the watch.  


Throughout the years there have been pieces of technology that have gone far above and beyond the call of duty. The PloProf is one of those pieces. It. is. insane. When Omega first launched the Seamaster 300 in 1957, it was actually only water resistant to 200m and was only called the 300 because it sounded better. So it was a reverse twist of fate that the PloProf was actually tested under far stricter conditions than its claimed 600m. Tested to a simulated depth of 1370m, the only reason the watch wasn't tested further was that the glass expanded and had jammed the second hand stopping the watch. Once the pressure subsided the movement started working perfectly again. Whilst Rolex had opted to go for a more high-tech approach, Omega instead went for sheer brute force (very well engineered and brilliantly designed brute force, mind). Not that I think it was a bad approach, as in fact I prefer the sheer nonsense of the PloProf over the more refined and technically advanced Sea-Dweller.  At the time the PloProf was Omega's most expensive piece, but I doubt that they ever recouped the cost of development even with a nine year production time. For the general public its unwieldy size of 54mm by 45mm was just too huge. Even today it's considered a beast, so think what it must have been like back in 1970!


I think it would be a fair assessment of Rolex to say that they are the more conservative of the two companies. Whilst Omega was designing a completely new piece that would just tough it out against helium, Rolex decided on a more elegant approach and took to modifying an existing Submariner reference, the 5513. It is interesting to note that on the Rolex website they write that making a watch impervious to helium is "a practically impossible task". Obviously no-one told them about the PloProf! What Rolex developed would soon become the standard for all professional diving watches thereafter, the Helium Escape Valve or HEV. By having a uni-directional valve on the side of the watch, it would allow the small helium molecules to exit the watch without causing any damage. In November of 1967 Rolex applied for a patent for the HEV valve but released the new Ref. 1655 anyway, two years before the patent was granted.


Source: timepiecechronicle the-call-of-the-sea-the-omega-seamaster-600-vs-the-rolex-sea-dweller



Rail dial


So what is a rail dial? This is actually quite confusing cause it isn’t about the minute track, in French called “chemin de fer” or rail track. It is actually about the alignment of the fonts! Obviously, the alignment of the wording on the dial is lined up on a rail dial. Most precisely, the last “E” of “superlative” and the “Y” of “officially” are perfectly aligned, as are the “C” of “chronometer” and “certified”. This creates a very pleasing and unusual vertical “gap”, a space between the lines of the designation on the left and those on the right

Rolex Rail Dials can be found on select vintage Explorer II ref. 1655 and Explorer II 16550 models. The correct serial number for a « RDWSD » is included between 5.7 million and 6.2 million.


The distinctive characteristics of the rail dial are as follow:


  1. The "C" of Chronometer lines up with the "C" of Certified of the line below.


  1. Secondly the font of the depth markings are always in italics


  1. The hour markers (tritium dots) are closer to the minute track than the regular dial


  1. The only version of the SD dials where is marked "T SWISS T <25", including COMEX 1665


  1. Longer minute markers.


  1. Serial 5.7mil to 6.2 mil.


Source Ed Delgado website drsd com



The Sea-Dweller Rail Dials were produced for two short years from 1977 to 1979 by the Stern dial makers (the same Stern family of Patek Philippe fame). As a result, they are quite rare on the vintage market. This is especially true since Rolex service dials fitted to these particular Sea-Dweller watches did not have the perfectly aligned “Cs” – therefore, they are not considered Rolex Rail Dials.


Model information and characteristics

  • Ttriple-lock or triple system waterproof crown, featuring a triple gasket system, identified by three dots on the crown. The Twinlock system included one O-ring gasket under the crown to push against the case to create a wall against outside moisture. However, the second O-ring gasket (hence the “Twin”) was located inside the tube surrounding the winding stem to keep the water out even when the crown was unscrewed. The third-generation waterproof winding crown named Triplock, is fitted with a triple waterproofness system. It was introduced in the late 60s early 70sto equip the Sea-Dweller, the model designed for professional deep-sea divers. To further reinforce the waterproofness, even if the crown should remain unscrewed under water, Rolex engineers added a second O-ring inside the tube. This acts as a kind of airlock, safely keeping out even the minutest particles. Today, the Triplock system equips all the brand’s divers’ watches as well as a number of other Professional models.
  • Case made from solid block of stainless steel and Waterproof to a maximum depth of 600 m (2000 ft).
  • Bi-directional rotatable bezel
  • Perpetual rotor in the self-winding wristwatch mechanism, allowing the watch to run continuously, as every slight movement of the wrist winds the movement. The energy generated is stored in the mainspring, allowing the watch to continue to function with no movement for several days.



This stunning example of the Rolex Sea-Dweller 1665 reference is in really good vintage condition. It has all the good parts what makes this a great looking vintage piece

Dial: Original tritium dial with stunning " patina. Similarly to the case, the dial is in excellent condition, the hour markers of the dial have a really nice patina with a kind of creamy colour.

Hands: Original Tritium hands. The creamy patina of the hands match the patina of the hour markers perfectly.

Case: the case has been refinished. Reference & serial numbers are fully legible.

Crown: Original Rolex triple lock crown.

Bezel & Insert: comes with a lightly faded fat font Mark III bezel insert. It is a sharp original bezel with original "Hooked 5" insert with Tritium dot present..

Bracelet: Rolex 93150  solid oyster link bracelet with 585 end links. Bracelet has some stretch and wear but is in really great wearable condition.

Movement: Bought serviced serviced by our watchmaker.. Running perfectly with a one year service warranty. The watch carries the the self-winding automatic 1575 movement polished decorations and circular Côtes de Genève finishings. The movement features 26 jewels and a bi-directional central rotor, beating at 19,800 A/h, with a power reserve of 42-hours. The movement is clean, and during the time of testing the watch was fully functional.

Accessories: None.

Notes: Absolutely stunning example of a super desirable Rolex Sea-Dweller 1665 with an attractive dial, original hands and original folded bracelet. Very hard to find these in this condition.

Overall, the Rolex Sea-Dweller 1665 is noteworthy, both for its design and execution. This Great White is remarkably well preserved. 

As with all of our pre-owned watches this watch comes with a full 12 month warranty with ourselves that will be invoked from the day of purchase.

Viewings can be arranged at our office by appointment.



This particular watch has just undergone a full service. This work was carried out by our Rolex authorized watchmaker using Rolex parts.


As with all of our pre-owned watches this watch comes with a full 12 month warranty with ourselves that will be invoked from the day of purchase.


If you put it on your wrist, you feel you have locked and Wrist Icon!




  • Brand: Rolex
  • Model: Rolex Sea-Dweller
  • Serial number: 6220987
  • Reference: 1665
  • Year: Circa 1979
  • caliber: Automatic 1575 movement w/date (base caliber 1530) 26 jewels beating at 19.800 betas per hour.
  • Case: It has a stainless steel case with screw down case back. waterproof screw-down crown, rotatable time-lapse diver's bezel, acrylic crystal.            Excellent case with some wear from use. Comes with a rare transitional caseback. Serial and reference numbers are crisp and well defined.
  • Bezel and insert: comes with a lightly faded fat font Mark III bezel insert. It is a sharp original bezel with original "Hooked 5" insert with Tritium dot present.
  • Dimensions: 40 mm diameter;
  • Crystal: Plexiglass super dome
  • Dial: Excellent black matte Mark II dial with warm creamy markers.
  • Bracelet/Strap: stainless steel Rolex 93150 period correct folded oyster bracelet with a Rolex signed 93150 flip lock buckle with diver extension. It wears really good, since it is a super tight original Rolex 93150 Oyster bracelet with 585 end links. Bracelet has date code VD to (1979)) and has 11 links + the original PATENTED diver extension. Bracelet has been polished and the Rolex crown on the clasp is nice & crisp.
  • Lug Width: 20mm
  • Box/Papers: only watch



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