In 1967, Rolex changed the world of waterproof watches. . . again. The first Rolex Sea-Dweller (Ref. 1665) was the first production wristwatch featuring a helium escape valve. This is particularly useful for saturation divers, or divers who stay underwater (and/or under pressure) for extended periods of time. It’s crucial that saturation divers breathe a gas mixture that includes helium (as opposed to nitrogen). Helium is small enough to get past gaskets and into your watch, which is fine while the watch is under pressure. However, as it decompresses, the increasing volume can literally make your watch explode. The helium escape valve allows a purge of helium from your watch, preventing potential damage and/or explosions. In short, the helium escape valve is a pretty big technical achievement.
Most modern Rolex watches are products of slow and steady evolution: decades of small changes resulting in a nearly perfect purpose-built tool. The Rolex Sea-Dweller is no different. It was released more than a decade into the Submariner’s life, and is very similar to the brand’s flagship dive watch. The Sea-Dweller is more robust, and thus exhibits a slightly chunkier case. The 40mm 1665 features 610 meters of water resistance, the all new helium escape valve, and a date complication without a cyclops crystal. It was a monumental shift in the world of dive watches. The 1665 is nicknamed the “Double Red” due to its two lines of red text reading “Sea-Dweller Submariner 2000”. In 1977, these lines of red text were replaced with white, appropriately nicknaming the watch “Great White”.
The next year in 1978, Rolex released the new Sea-Dweller (Ref. 16660), also known as the “Triple Six”. This update doubled the depth rating to 1220 meters, adding a sapphire crystal and tweaking the helium escape valve. This new reference also saw an upgraded movement: the caliber 3035. One decade later, Rolex released the Sea-Dweller (Ref. 16600). This reference saw another movement upgrade to the caliber 3135, but remained 40mm in diameter. In 2008, the 16600 was replaced by the Deepsea Sea-Dweller (Ref. 116660). This 44mm behemoth has a depth rating of 3900 meters and a Cerachrom bezel. The late 2000’s is when most Rolex watches received the Cerachrom treatment: a welcome upgrade to collectors and enthusiasts. In 2014, Rolex released the gradient-dialed Deepsea D-Blue Sea-Dweller 116660 honoring James Cameron’s deep dive in the Mariana Trench. This was essentially a special edition of the 116660 – not much changed here. That same year, Rolex released the 40mm Sea-Dweller 116600 (yes, these reference numbers are horribly confusing). This Sea-Dweller is also known as the SD4000. The SD4000 was a sweet spot for many enthusiasts – all the modern spec with a wearable 40mm case. However, it was discontinued in 2017. That year, the SD4000 was replaced by the Sea-Dweller 126600, also known as the SD43. The SD43, as you may have guessed, has a 43mm diameter. It brings back the red “Sea-Dweller” text, as well as a cyclops date window for the first time in the model’s history.
The Rolex Sea-Dweller (Ref. 16600 & 16660) is a classic tool watch. The “Triple Six” and 16600 are two exemplary references: demonstrating the capabilities of the Sea-Dweller before it ballooned in size. Most references (all before 2000) have tritium dials, meaning they likely have some sort of beautiful patina. Everest’s Curved End rubber, leather, and nylon straps are tailor fit to the dimensions of the Rolex Sea-Dweller (Ref. 16600 & 16660), seamlessly hugging the case and lugs. Dress it up with leather, dress it down with rubber or nylon, or reduce the weight with either of the three – Everest has you covered. If you’re looking for a strap for your Rolex Sea-Dweller (Ref. 16600 & 16660), Everest bands are your best bet.