COMEX and the creation of the Rolex Sea-Dweller ref 1665

Fratellowatches recently posted about Henri Germain Delauze’s passing away. He was the founder of COMEX, a professional dive company from France, who initiated the creation of dive watches that were able to descent to greater depths than ever before….

The Rolex Sea-Dweller 1665 is one of the most sought-after vintage Rolex models of today. Especially the so-called Single Red and Double Red versions are sold for record prizes at auctions. Rolex created the Sea-Dweller to solve problems COMEX, a professional dive company, had with diving at great depths.

Before Rolex released the Sea-Dweller reference 16600 as we know it, they produced a specially prepared Submariner for the French dive company COMEX. Due to the depths they worked at, the divers experienced failure in the watches during decompression, as crystals broke due to an internal build-up of pressure from helium. The helium was used as gas-mix in the diving bells, the divers stayed in for a period when diving at great depths.

Rolex modified regular Submariner watches (reference 5513) to incorporate a helium escape valve and later issued examples with a reference specifically for COMEX, which became the reference 5514.

With this development Rolex launched a new reference fitted with helium escape valves for commercial production, and in 1967 the first batch of ref. 1665 Sea-Dwellers were released to authorized dealers and selected divers for testing.  These first watches, of unknown quantity but believed to be fewer than 100, were released prior to obtaining a helium-escape valve patent and feature the words ‘Patent Pending’ on the case back.

Rolex Sea-Dweller Submariner 500M - Single Red

Later the so-called Single Red Sea-Dweller, first without Gas Escape Valve, was released. This Sea-Dweller Submariner 500M was only produced for a few years and are very rare these days.

Starting in the late 60’s, Rolex produced the incredibly famous Double Red Sea-Dweller, also called DRSD by Rolex fans. This was the first Sea-Dweller to be able to reach a depth of 2000ft or 610 meter.

The original Sea-Dwellers were offered with red printing on the dial until 1977. Research by collectors has led to distinguish four versions of dial development:

  • MK1: Only found on the ‘Patent Pending’ examples, the Sea-Dweller and Submariner print are of equal size. The red print was printed over the white; now-a-days many have faded to a pink or almost white text; the Rolex logo, also named coronet, has a characteristic, heavier style.
  • MK2: The Submariner 2000 text is smaller, the coronet remains the same. This version is found on both the ‘Patent Pending’ and early ‘Patented’ versions.
  • MK3: The red print remains similar to the MK2 although the depth rating text is heavier. The coronet, now more elongated, undergoes significant changes.
  • MK4: The final version of the original dials is again a slightly heavier print for both the red and white text; the loop of the 6 (of the date font) is now closed. The coronet has broader fingers and a more pronounced open ‘foot’.

Due to their waterproof characteristics all Ref. 1665 ‘Double Red Sea-Dwellers’ featured the case serial number on the inside of the case back to prevent switching during service. Early examples used the last 3 digits of the serial number, the later ones the full serial number.

Below are photos of a MK2 and MK3 dial.

MK-II

Rolex Sea-Dweller 1665 - Mark II dial

MK-III

Rolex Sea-Dweller 1665 - Mark III dial

By the end of the 70’s Rolex changed the dial with two red lines of text to a dial with all white text, the so-called Great White. Since Rolex didn’t change supply to the different parts of the world all at once, and since Rolex used already produced parts before producing new parts, the change from Double Red Sea-Dweller to Great White didn’t happen overnight. Some Great White versions still had a Double Red caseback and in the Far East Double Red’s where deliverred much longer, some even reported until the early 1980’s. In the USA and Europe the change to Great White was made in 1977.

Mk-I

Great White with Mark I dial

Since there’s just too much to say about vintage Rolex Sea-Dwellers I’ll suggest some websites for those who like to read more about this magnificent mother of all divewatches:

Frank Geelen

Frank Geelen is an expert on Haute Horlogerie and his horological heart beats faster from beautiful hand-finished mechanical movements. He loves to explain all technical details of complications like tourbillons, minute repeaters, constant force escapements and column-wheel chronographs and he has been doing that for more than seven years. Besides publishing daily here at Monochrome Watches, Frank also writes for several other publications, both online and offline.

View all articles by Frank Geelen

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