During the late 1960s, commercial work in the oceans and seas created professional diving organizations that needed tool watches designed for conducting safe diving operations at greater depths – known as saturation diving.
This led to the development of the first ‘ultra water resistant’ watches. In collaboration with COMEX - a France-based professional dive company which is considered as the NASA of the sea - Rolex developed its “Submariner” model to meet the most stringent technical and professional demands of the professional deep-sea diver.
In the process, Rolex eventually produced a very different watch from the Submariner, the “Sea Dweller”.The genesis of these watches has already been described on the forum:
COMEX divers not only needed solutions for water resistance at extreme depth, they also faced the danger of explosive decompression caused by helium penetrating the interior of the watch (divers breathed the mixture of oxygen and helium within their hyperbaric chamber after lengthy deep sea dives). To maintain a pressure identical to that underwater, the mixture in the hyperbaric chambers remained the same during the different phases of work and rest periods. This system was designed to eliminate the need to depressurize the chamber after each phase of work.
Before returning to free air, and depending on the depth attained, a period of depressurization was necessary to equalize the internal and external tension of the human organism. Though the process of depressurization is slow, the gas that accumulated inside the watch, having no means to escape fast enough, exploded the crystal off the watch, thereby risking injury to those inside the chamber and severely damaging an expensive watch.
Rolex collaborated with COMEX to develop a solution by installing a one-way pressure escape valve on the side of the watch case, at the nine o’clock position. The one-way valve will begin to equalize the pressure inside the watch when the difference between the exterior and interior of the watch exceeded 2.5 kg. per sq. cm.
The Helium Gas Escape Valve (HEV) was featured and tested on the Single Red and Double Red Patent Pending Submariner Sea-Dwellers, circa 1967-1969. Once the testing was successfully completed and Patent of the HEV approved, COMEX placed a special order with Rolex for the supply of a number of dive watches featuring the HEV; the first batch consisted of ten thin case Sea Dweller - for the top divers only - and Submariner.
The development and delivery of this unique reference evolved from a modified ref. 5513 to the final ref. 5514 with big case back numbers, circa 1975. The 5513 can be found in a number of iterations:
· The earliest ref. 5513 COMEX watches that have surfaced circa 1969/70 have non-HEV cases, non-logo dials and case backs which are engraved ‘Rolex Comex.’ The serial number engraved inside the case back matches the serial number between the lugs at 6 o’clock.
· The ref. 5513 COMEX watches with HEV (an improved version introduced post Patent approval) that followed (circa 1972) were mostly produced with a small or medium sized issue number engraved on the case back and a plain matt non-logo dial.
It is believed that approximately one third of the original issued ref. 5513 COMEX watches had a matt logo dial and very few have survived, thus making the ref. 5513 with the original COMEX logo dial configuration one of the rarest COMEX watches to exist (estimates have been made in the region of 50-60 watches in total).
The watch presented here is the archetype of the 5513 Comex, with its non logo dial and small delivery number.
It comes with a letter from the diver, telling the story of the watch. Of course this is a key feature for such a watch, because the glorious past of the timepiece is exactly what makes it desirable.
The most amazing thing is when such an incredible watch not only a rare piece and a “big soul”…but also a beauty queen !
Source: wikipedia, Worth Point, Ginault.com