In 1960s, Rolex made a partnership with Comex, which was a underwater engineering company in France to create the dive watches especially for them. In order to adapt to deep sea saturated diving, Rolex added a new patented helium escape valve to the side of the case on basis of Submariner Ref.5513, then the Ref.5514 was born, which was the origin of the famous fake Rolex Sea-Dweller.
In 1967, Rolex launched the Ref.1665 to public after the several tests, and Sea-Dweller had been formally established in this year. 10 years later, in 1977, the new Ref.1665 removed the words ”Sea-Dweller” and “Submariner” printed in red on the dials, only white printed Sea-Dweller taking place of it. It was just this year Sea-Dweller broke away from Submariner collection to be a single series. Then, in the following days, Sea-Dweller had been kept developing and improving.
The first generation Sea-Dweller Ref.1665 was equipped with calibre 1575 and was water resistant to a depth of 610 meters. The second-generation Sea-Dweller Ref. 16660 had been driven by calibre 3035 and its water resistance was to 1220 meters. While for the third-generation Ref.16660 equipped with calibre 3135, the water resistance was to 1220 meters too. Then in 2008, Rolex improved the ability of water-resistance on basis of the original Sea-Dweller, being to a depth from 1120 meters to 3900 meters, releasing a new Sea-Dweller Deepsea Ref.116660.
Rolex imitation watch with Oystersteel bracelet has been assembled with a Ringlock case which provides great resistance to the pressure from underwater. The inner part is equipped with a very strong nitrogen alloy stainless steel ring as the middle bracket of the watch. Through the complex design, finally Deepsea could resist the pressure up to 3 tons.