The Rolex Oyster Perpetual Date Sea-Dweller is a line of diver's watches manufactured by Rolex, capable of withstanding water pressure at a depth of 1,220 meters (4,000 feet). The Sea-Dweller was developed from the Submariner for the Comex S.A. industrial deep-sea diving company by increasing crystal thickness and incorporating a helium escape valve for saturation diving.
Another feature setting it apart is the absence of a date magnification bubble present on most Rolexes. Since 1976 the Rolex Sea-Dweller is a standard issue diving watch for every Comex diver. The current Comex Sea-Dweller Rolex reference number is 16600.
The design and actual availability of diver's watches certified for more than 1,000 meters (3,281 ft) is not solely explicable by practical diving needs.
The diving depth record for actual off shore diving was achieved in 1988 by a team of professional divers of the Comex S.A. industrial deep-sea diving company performing pipe line connection exercises at a depth of 534 meters (1752 ft) of sea water (MSW) in the Mediterranean Sea. The diver's watches used were Rolex Sea-Dwellers.
In 1992 Comex diver Theo Mavrostomos achieved a record of 701 MSW (2300 ft) in an on shore hyperbaric chamber. He took 43 days to complete the dive. The watch used during this scientific record dive, where a hydrogen-helium-oxygen gas mixture was used as breathing gas, was also a Rolex Sea-Dweller. Rolex used this achievement in advertising campaigns.
The complexity and accompanying high costs of professional diving to extreme depths and the development of deep water atmospheric diving suits and remotely operated underwater vehicles in offshore oilfield drilling and production effectively nixed the need for ever deeper non-atmospheric manned intervention in the ocean.
Rolex Sea-Dweller DEEPSEA
At the BaselWorld watch and jewellery show 2008, Rolex announced the introduction of an updated Sea-Dweller model, named the Rolex Oyster Perpetual Date Sea-Dweller DEEPSEA. The 1,220 m (4,000 ft) depth rating on the original Sea-Dweller is increased to 3,900 m (12,800 ft) on the DEEPSEA model. This is equivalent to 3.9 kilometres or approximately 2.4 miles. For testing the Sea-Dweller DEEPSEA watches water resistance Rolex uses test equipment developed for them by Comex.