Rolex Sea Dweller

• Rolex Daytona

The search for new energy reserves after the second world war meant divers were having to go further in the search for new resources.Many of us will be aware of the dangers faced by divers ascending from great depths. What is less commonly known is that watches also suffer from it. When divers were in decompression chamber, the helium in their watches couldn't escape as rapidly as the chamber was decompressing. This resulted in the air pressure inside the watch blowing the crystal out of the case. A French company that built compression chambers (Comex) decided to do something about this. They took a normal rolex Submariner and added a gas escape valve opposite the watch winder. These modifications worked well and Rolex watches put the watch into production with a strengthened case in 1971 as the Sea Dweller. The prototype Sea Dweller was a non chronometer, plastic glass rolex Submariner with the dial marked 660 feet/200 meters. On the back it had Comex' s insignia and on the side was the gas escape valve. Comex divers were equipped with an assortment of Rolex watches, the Sea Dwellers were used on "saturation"dives where as the rolex Submariner were used in "atmospheric" dives. Due to the extreme conditions in which these divers operated every six months the watches went back to Rolex watch for an overhaul. These watches were not just meticulously overhauled but in many cases upgraded each time. It is not unusual to see a 1970's watch with the later "hacking" movement with a 1990's dial.

• Rolex Datejust

The first Sea Dwellers were actually called the "Submariner 2000 Sea Dweller" which was printed on the dial in red writing. This disappeared in 1973 and in it's revised form the watch continued until 1980, when it received a major overhaul. Like most other Rolex watch models this watch now had a sapphire mineral glass, a rapid date change mechanism, a new gas escape valve meaning it could as standard reach 4000 feet/ 1220 meters. The bracelet also differed from that of the Submariner. Both the end piece and the expansion link were different. The "Flushfit" was now machined out of solid steel instead of being pressed from sheet. The expansion link was made from sheet steel: on the Sea-Dweller the second link from the clasp is machined from solid steel with a cut out for the expansion link spring bar.

• Rolex GMT Master

The Sea Dweller has remained popular since it's introduction and hasn't been out of the catalogue in over twenty years. As a professional tool for the people whom it was developed for the Sea Dweller is without peer. No diver working for Comex has been allowed to dive without one since 1976.

• Rolex Explorer