This 2020 Rolex Deepsea Sea-Dweller D-Blue 126660 with box and papers is in excellent condition and has passed our in-house due diligence and inspection criteria.
 
Case width 44mm (excluding crown)
D-Blue (Blue/Black) Dial
Chromalight Display
Rolex Ring-Lock System with Helium Escape Valve
Screw-down Crown
5.5 mm thick Sapphire Crystal
Rolex Calibre 3235 Automatic Movement
Black Uni-directional Rotating Bezel
Stainless Steel Case
Titanium Caseback
Matt Stainless Steel Oyster Bracelet
Folding Oysterlock safety clasp with Rolex Glidelock extension system 
Fliplock extension link
Rolex Box (inner and outer)
Green COSC Tag
Original Rolex AD card dated August 2020
Green Leather Card Holder
Rolex Booklets
Rolex Warranty until 2025
TWS Valuation Certificate
Watch Register checked
 
The Rolex Sea-Dweller, another 'tool-watch' designed by the company to carry out a specific job.
 
In the 1960's professional divers needed a watch that could handle the enormous sea pressure at a depth of 300 metres but even the existing Submariner couldn't dive to those depths. So Rolex came up with a solution in the form of the Sea-Dweller 2000. As the moniker suggests this was a watch that could handle a depth of 2000 feet without drama.
 
However, in 1978, the Sea-Dweller 4000 upped the ante by having a unique Helium Escape Valve (or equalisation valve) built into the case which meant that the new watch could survive conditions that would normally crush the workings of any other so-called diver's watch. This simple spring-loaded valve allows the microscopic helium particles to escape from the watch as the diver ascends from the depths and so efficient is the mechanical design that it works all on its own without any intereference from the diver.
 
Once again, a real-life technical problem solved by Rolex with a simple but highly efficient design. For the record, the Sea-Dweller is only available in stainless steel and no other optional finish. 
 
As usual the Sea-Dweller utilises the famous Oyster case which is milled from one solid piece of steel whilst the movement is shielded by a screw-down case-back plus screw-down crown for the winding mechanism . The front of each watch is also hermetically sealed with a specially hardened sapphire crystal. All engineered to perfection and totally fit for purpose.
 
Launched in the late 1980s, the reference 16600 is virtually identical to the late “Triple Six,” maintaining its sapphire crystal and its 1,220 meter water resistance.
 
Over its remarkably long production period, the luminous material evolved from tritium to Luminova, and then to SuperLuminova.
 
You can easily tell which is which by looking at the bottom of the dial – T Swiss T<25 indicates Tritium, Swiss indicates Luminova, and Swiss Made indicates SuperLuminova.
 
The reference 16600 also utilizes the caliber 3135, a slightly improved version of the caliber 3035. It has a longer power reserve and a full-fledged balance bridge, instead of the balance cock. The reference 16600 was discontinued after 20 years in Rolex catalogues, making it the longest lasting Sea-Dweller reference.
 
The Deepsea that was announced in 2008 arrived with a 44mm width case and its water resistance rating uplifted to an impressive 3,900m deep. The lume is Chromalight, the bezel ceramic and the sapphire crystal is 5.5 mm thick.
 
Named with reference to the experimental Deep Sea Special watch Rolex made in 1960, this watch marks the Sea-Dweller evolving into a broader collection containing both standard Sea-Dwellers alongside Deepsea models.
 
There are four modern variations of the Sea-Dweller today, and two of them are Deepsea models. The first has a black dial, while a second model (released in 2014 and the one we have on sale here) has a gradient blue dial to commemorate the 2012 expedition in which James Cameron piloted a submersible craft called the Challenger Deepsea to the bottom of the Mariana Trench.
 
Rolex had made a special prototype Deepsea watch that it strapped to the robotic arm outside the vessel to prove its water resistance. That watch was a substantial 51.4mm wide and 28.5mm thick, but it survived down to 10,908m.