Patent Pending DRSD

Rolex Double Red Sea Dweller with the Patent Pending Caseback 

by Ed Delgado



The Rolex Sea-Dweller was developed in close collaboration with the French deep sea diving company COMEX. Their divers required a timing instrument that could withstand their working depths, plus be able to remain intact in ascent and decompression. Most of the watches manufactured at that time could not tolerate the extreme depths.  Helium gas would build up inside the case and at decompression the gas pressure would increase.  The rising inner pressure would eventually be released by breaking the crystal, the weakest point in the case design.

Rolex first developed the helium release valve in the 1960s and incorporated it into some of their Submariner watches delivered to the French diving company, COMEX.  The testing of these specially adapted Submariner 5513 models was so successful that Rolex specifically made a batch of watches for COMEX and the watch was given an official model number, 5514.  This was such a success that Rolex decided to market the watch as model number 1665 by 1967.

The 1665 was initially rushed to production and some early watches were sent to dealers for promotion or early sales.  Some authorities state that the number is less, about 150, while others argue that the number is much larger and that several hundred may have been made.

The helium valve had been developed and the patent had been applied, but Rolex had not received final approval. Therefore, the engraving on the caseback of these early sea dwellers stated in parenthesis “Patent Pending.”

Regular production of the double red sea dwellers started in 1971 and ended in approximately 1977.

There were some characteristics on these watches that made  different from the regular production of double red sea dwellers.


NOTE: You might have noticed that the print of "Sea-Dweller, Submariner 2000" appears as white, but in reality, the red has faded to a very light pink which the photograph failed to capture.. Here is a close up..



First, the case was much thinner than the regular production (1971-77).

They all had a small helium valve at the 9 o’clock position.

Marked with the model number 1665

Marked with serial 1.7 million to 2.2 million



The caseback had the Rolex coronet and under “ROLEX” across the back and not circularly around the caseback.

The following was also engraved “Oyster Gas Escape Valve” and in parenthesis “Patent Pending”

Inside the Caseback.

The inside of the caseback showed the usual Rolex markings with the model number, 1665.

The last three digits of the serial are engraved inside.

Lastly, the quarter and year of production of the caseback is engraved.


Crown and tube.

The crown was a triplock without the external rubber “O” ring in the tube. The coronet in the crown did not have a line or dots under it as the current triplock.



The crystal is a acrylic crystal with a high dome.


The dial is a black matt with white indices and plots. The coronet had a “flat” bottom and the “L” of Rolex lined up perfectly under it.

The words “Sea-Dweller” and “Submariner 2000” in red possibly printed directly on the dial or over white paint? The print is clear and easily demarcated. The font is the same for both lines as opposed to the later dials that used a smaller font for “Submariner 2000”.

Most of these dials, the red print has faded to a light pink or almost yellow. Therefore, the double pink or double yellow dials.

The depth markings of “2000ft=610m” sans sheriff.

Small markings in the dial for “Swiss – T < 25” indicating a tritium dial.



The bracelet is a Rolex Oyster 9315 with folded links and 380 end pieces. About thirteen links should be present.  The extension of the bracelet may state “patent pending”.




Box and Papers and other documentation.

As any other watch, these sea dwellers were sold with inner and outer boxes.

The green tags with the model number in one side and the full serial number is in the other side.

Rolex Booklet with full serial.

Rolex certified chronometer tag.

Chronometer certificate

This particular watch came with a very interesting letter from its original owner detailing its history for over its initial 34 yrs.. A pretty unique watch!

I don’t know how many of the original Patent Pending Sea-Dwellers have survived but those in this condition and this provenance are probably few and far between.

In all and from my experience, the PPDRSD is trully a very rare watch. In my estimation, there were less than a few hundred examples ever made. Those samples run in at least two distintive batches (ie close serial numbers). And the mark I dial, is the only dial associated solely with the PPDRSD.



New Information about Patent Pending DRSD by Delgado

I have been keeping detailed records for the last few years and this had led me to believe that there is more than 114-120 of these watches around in various configurations. The PPDRSD still a very rare watch and I belive that it was a very limited production.

They were also made in batches similar to the comex or mil subs.

So far there are three batches at
1.7 mil, 2.1 and 2.2 mil.

All the casebacks were done in late 1960's and a poor date stamp inside the caseback.

The most common dial is the mark I followed by the mark II.

Mark I dials are only seen in PPDRSD..

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