1989 Rolex Sea-Dweller (Ref. 16600)

Within the history of Rolex models, few topics spark more debate than the significance of one model versus another; however, the Sea-Dweller is undoubtedly one of the most important watches ever created. First introduced in 1967 with the reference 1665, the Sea-Dweller featured innovative patented technology that helped further human exploration to parts otherwise considered impossible to reach. In collaboration with Comex and utilized in the famed SeaLab missions, the Sea-Dweller built upon the existing Rolex Submariner platform to increase the depth rating of the watch to an impressive 2000ft. This impressive increase in possible depth was the result of bulking up the case, but more importantly, the invention and development of the Helium Escape Valve or HEV, which allowed for helium molecules to transfer in and out of the watch case without damaging the watch.

Helium gas was essential in the breathing gas mixture used during the experimental saturation diving missions at the time; however, due to helium being such a small gas particle, it was able to enter watches during the missions, but without a method for the gas to escape would cause the watches to catastrophically fail upon decompression. The invention of the HEV was revolutionary as it allowed the helium gas watches to "escape" during decompression, thus making the watch able to reach unheard-of depths at the time.

The Rolex ref. 16600 is the third version of the Sea-Dweller and was introduced in 1988, directly succeeding the very transitional ref. 16660 "Triple 6" model, and was replaced in 2008. The ref. 16600 boasts an incredible depth rating of 4000ft or 1220m, utilizes a sapphire crystal and a unidirectional click-spring bezel, and employs the Rolex in-house cal. 3135 with quick-set date functionality, and features the improved 93160 Oyster bracelet with solid end pieces.