The Submarine that Dwells on Your Wrist

It may not be as universally renowned as the Submariner, GMT or Daytona, but the Sea-Dweller has a long and rich history at Rolex. This is the brand that made a name for itself with the 1927 Oyster case as well as the iconic 1954 Submariner. While the Submariner was popular and performed well, Rolex wanted to go further. In 1967 it released the first Sea-Dweller, a tool watch designed for niche, extreme professions that became evocative enough to remain in production for more than 50 years.

The big headline for the original Sea-Dwellers was of course the helium escape valve, developed with undersea engineering company COMEX for use in pressurised chambers. This gadget, functionally useless in all other practical situations, soon became a hallmark of diving horology.

The Sea-Dweller itself went on to enjoy many upgrades over the years, and in 2008 the first Deepsea model was launched, with a staggering water resistance of 3,900 meters. When you think that a single square meter of water weighs about a metric ton, it is a truly remarkable achievement. 3,900m is more than the average depth of the ocean floor. The Deepsea uses "Ringlock" case architecture, a cerachrom bezel and a whopping 5.5mm thick sapphire crystal to keep it safe under the waves.

In 2014, the "D-Blue" version was launched at a special press event - ultra-rare for Rolex - to celebrate Avatar-director James Cameron's descent to the world's deepest point, the Challenger Deep in the Mariana Trench. Attached to the side of his vessel was a custom Rolex with even more amazing specs, which survived the voyage to 10,900m without a scratch. The D-Blue dial features graded colouring - another first for Rolex - from blue to black like the ocean, and green text that matches Cameron's submarine.

New at Baselworld 2018, we were pleased to see this titan of the depths had received another update. With the same extraordinary technical specs, it remains an impenetrable fortress of a watch, and the diameter is still a sturdy 44mm. But the sides and lugs of the watch have been pleasingly slimmed down, and the bracelet and Oysterlock clasp have been redesigned to match. This updated strap comes with both the "Fliplock" extension for wetsuits and the "Glidelock" in-clasp sliding function.

The bigger news is the update to what's inside that beast of a case. The Deepsea now comes equipped with the stellar 3235 movement, which was new in 2016, and only added to the red-line Sea-Dweller last year. The 3235 is the very best of the most modern mechanical technology. The energy-efficient "Chronergy" escapement allows the calibre to tick for a full 70-hour power reserve, and it uses a cutting-edge combination of nickel and phosphorus for extra resistance to magnetic fields. Rolex not only has the 3235 COSC certified, but also tests it in-house for even greater precision: just +/- 2 seconds per day.

The Deepsea will never appeal to all tastes, and will never seek to do so. Many collectors find the watch much too imposing for their wrists, but others among us can't help but be compelled by its incredible history and the astonishing level of technology it represents. With the updated case and D-Blue dial, it also doesn't look half-bad.