Submariner
Sea-Dweller
THE WATCH THAT CONQUERED THE DEEP
A legend among professional divers’ watches, the Oyster Perpetual Sea-Dweller is an ultra-resistant tool watch that was created to accompany the pioneers of deep-sea exploration.
The Sea-Dweller, launched in 1967, is a technical divers’ watch that was designed for and in collaboration with the pioneers of professional deep-sea diving, who spent extended periods underwater. Initially guaranteed waterproof to a depth of 610 metres (2,000 feet), then, from 1978, to 1,220 metres (4,000 feet), it played a vital role in the exploration of the deep. This ultra-resistant tool watch accompanied the first experimental underwater habitat programmes. Over time, it has become a symbol of the special ties linking Rolex and the world of undersea exploration.
The Sea-Dweller is equipped with a specific technical feature: the helium escape valve, a decisive innovation patented in 1967. This safety valve on Rolex divers’ watches created for great depths allows excess pressure built up inside the case to be released during a diver’s decompression phase in a hyperbaric chamber – a process inherent to saturation diving – without compromising the waterproofness of the watch.
In 2017, the Sea-Dweller was updated for its 50th anniversary. It now features a larger 43 mm case – previously 40 mm in diameter – and calibre 3235, as well as the Cyclops lens on the crystal to magnify the date for easier reading.
CERACHROM BEZEL INSERT
The unidirectional rotatable bezel of the Sea-Dweller is fitted with a 60-minute graduated monobloc Cerachrom insert in black ceramic that allows divers to monitor their time underwater. This patented insert is made of an extremely hard, virtually scratchproof ceramic whose colour is unaffected by ultraviolet rays. In addition, thanks to its chemical composition, the high-tech ceramic is inert and cannot corrode. The moulded, recessed graduations and numerals are coated with yellow gold or platinum using a PVD (Physical Vapour Deposition) process. The bezel’s knurled edge offers excellent grip, to comfortably set dive time even when wearing gloves.
LEGIBLE AND FUNCTIONAL
In the underwater depths, being able to read the time with absolute certainty is a matter of survival. Great attention was paid to the legibility of the Sea-Dweller: the dial of this professional divers’ watch features a pared-back design and incorporates the Chromalight display. The simple forms of the hour markers – triangles, circles and rectangles – and the hands, which are clearly differentiated in size and shape, are filled or coated with a luminescent material emitting a long-lasting blue glow – for up to two times longer than traditional phosphorescent materials. On the bezel, the triangular ‘zero’ marker of the graduation is visible in the dark thanks to an embedded capsule containing the same luminescent material.
THE SEA-DWELLER, SUPERLATIVE CHRONOMETER CERTIFIED
Like all Rolex watches, the Sea-Dweller is covered by the Superlative Chronometer certification redefined by Rolex in 2015. This exclusive designation attests that every watch leaving the brand’s workshops has successfully undergone a series of tests conducted by Rolex in its own laboratories and according to its own criteria. These certification tests apply to the fully assembled watch, after casing the movement, guaranteeing superlative performance on the wrist in terms of precision, power reserve, waterproofness and self-winding. The Superlative Chronometer status is symbolized by the green seal that comes with every Rolex watch and is coupled with an international five-year guarantee.
The precision of every movement – officially certified as a chronometer by the Swiss Official Chronometer Testing Institute (COSC) – is tested a second time by Rolex after being cased, to ensure that it meets criteria that are far stricter than those of the official certification. The precision of a Rolex Superlative Chronometer is of the order of −2/+2 seconds per day – the rate deviation tolerated by the brand for a finished watch is significantly smaller than that accepted by COSC for official certification of the movement alone.
The Superlative Chronometer certification testing is carried out after casing using state-of-the-art equipment specially developed by Rolex and according to an exclusive protocol that simulates the conditions in which a watch is actually worn and more closely represents real-life experience. The entirely automated series of tests also checks the waterproofness, the self-winding capacity and the power reserve of 100 per cent of Rolex watches. These tests systematically complement the qualification testing during development and production, in order to ensure the watches’ reliability, robustness, and resistance to strong magnetic fields and to shocks.
THE OYSTER CASE, SYMBOL OF WATERPROOFNESS
The Sea-Dweller’s Oyster case, 43 mm in diameter and guaranteed waterproof to a depth of 1,220 metres (4,000 feet), is a paragon of robustness and reliability. The middle case is crafted from a solid block of Oystersteel. The case back, edged with fine fluting, is hermetically screwed down with a special tool that allows only certified Rolex watchmakers to access the movement. The Triplock winding crown, fitted with a triple waterproofness system and protected by an integral crown guard, screws down securely against the case. The crystal, with a Cyclops lens at 3 o’clock to enhance the reading of the date, is made of virtually scratchproof sapphire and benefits from an anti-reflective coating. The waterproof Oyster case provides optimal protection for the movement it houses.
CALIBRE 3235
The Sea-Dweller is equipped with calibre 3235, a self-winding mechanical movement entirely developed and manufactured by Rolex. A consummate demonstration of technology, this movement carries a number of patents. It offers outstanding performance, particularly in terms of precision, power reserve, convenience and reliability.
Calibre 3235 incorporates the patented Chronergy escapement, made of nickel-phosphorus, which combines high energy efficiency with great dependability and is also resistant to strong magnetic fields.
The movement is fitted with the blue Parachrom hairspring, manufactured by Rolex in a paramagnetic alloy. In addition to resisting strong magnetic fields, this hairspring offers great stability in the face of temperature variations as well as high resistance to shocks. It is equipped with a Rolex overcoil, ensuring the calibre’s regularity in any position.
The oscillator of calibre 3235 has a large balance wheel with variable inertia regulated extremely precisely via gold Microstella nuts. It is held firmly in place by a height-adjustable traversing bridge enabling very stable positioning to increase shock resistance. The oscillator is also mounted on the Rolex-designed, patented high-performance Paraflex shock absorbers, further enhancing the movement’s shock resistance.
Calibre 3235 is equipped with a self-winding system via a Perpetual rotor, which ensures continuous winding of the mainspring by harnessing the movements of the wrist to provide constant energy. Its oscillating weight has been fitted with an optimized ball bearing since 2023. Thanks to its barrel architecture and the escapement’s superior efficiency, the power reserve of this movement extends to approximately 70 hours.
The Sea-Dweller’s movement will be seen only by certified Rolex watchmakers, yet it is beautifully finished and decorated. Since 2023, it has also been marked with the words ‘Chronometer Perpetual’ and ‘Superlative Adjusted’ engraved respectively on the oscillating weight and on the bridges.
BRACELET AND CLASP: SECURE AND COMFORTABLE
The Sea-Dweller is fitted on the three-piece link Oyster bracelet. Equipped with a Rolex-designed, patented Oysterlock safety clasp that prevents accidental opening, this bracelet is furnished with the Rolex Glidelock extension system, also developed by the brand and patented. On the Oyster bracelet, this inventive toothed mechanism has 10 notches of approximately 2 mm, allowing the bracelet length to be effortlessly adjusted up to some 20 mm. The watch can therefore be worn over a diving suit up to 3 mm thick.
