Rolex Deepsea Sea-Dweller Watch Reference M116660-0001 – A Technological Marvel And A Brute To Wear

By Meor Amri Meor Ayob

The Rolex Deepsea was designed with the singular purpose; to enable extreme divers to make it their first choice watch for diving. Rolex incorporates the need for styling to cater for connoisseurs. 

The Rolex Deepsea is water resistant to a depth of 3,900 metres (12,800 feet). The 44 mm case is made out of 904L stainless steel with thick 5 mm domed sapphire crystal and unidirectional rotatable bezel with a 60-minute graduated, scratch-resistant Cerachrom insert in ceramic, numerals and graduations coated in platinum.

Featuring the Rolex 3135 Automatic movement, this one undoubtedly a robust watch with a tough movement that already certified by COSC and featuring stop-second and quick date change. Its balance, that receives an accurate microstella screw setting, beats 28.000 alternations/hour and is now endowed with the Parachrom spiral. The rotor moves in both ways for a better winding.

The dial itself is a myriad of information about the watch. Some would argue the bulk of the information would be better suited to be on the case-back but despite the “wordiness” of the dial, Rolex is able to balance it out nicely. The indexes as well as the hands are covered with the blue luminous material (Chromalight). More about this later.

The only comment I would like to make against the dial design is substitution of the 3 o’clock index with a date window. For symmetry sake, it would better if the date window was placed on its own.

Meanwhile, the case-back is not as devoid as some might imagine a Rolex case-back should be. Around the outer part are some wordings about the model name and a few logos. Nevertheless, the central part of the case-back is bare and is of a different material than the rest of the watch. Made out of grade 5 titanium, it was design as such as part of the Ring Lock System utilised by Rolex to allow the watch to operate in extreme water pressure.

In order to remain complete, the pressure is directly transmitted between the convex-shaped sapphire glass of 5 mm thickness and the case back, made of grade 5 titanium, by means of the central 904L steel ring, that ensures the rigidity of the whole. Thus, the deformation of the case is avoided and the waterproofness level increases as and when the external pressure heightens.

The consequent of this innovative design is an imposing central ring that Rolex has covered with the words “ORIGINAL GAS ESCAPE VALVE” and “RING LOCK SYSTEM”.

Rolex made the effort to create a patented divers extension. The patented Rolex Glidelock fine adjustment system allows divers to adjust the length of the bracelet to fit over a diving suit, without using any tools. A toothed panel under the clasp cover provides an extension of up to 20 mm in 2 mm increments. 

The helium escape valve mechanism utilized is unique. For Rolex, its engineers created a gas escape valve fitted with a spring: it opens when the difference in pressure between the inside and outside of the watch reaches 3 to 5 bars, allowing the helium to escape, thereby protecting the watch. 

The wearing experience is all about being able to carry the weight. The watch is a heavyweight and the weight is obvious to wearers (if you do wear it often, it’ll become natural after a while). Like I mentioned earlier, these are tool watches hence cannot be used in all occasions. Contrary to popular believe or what the Rolex advert tries to portray, the Deepsea cannot be used properly if you are wearing tuxedos or suits. The height of the watch is too high and can never slip pass the cuffs (if you decide to use a wider cuff, it can disappear in it but then you won’t look good – style wise).

The width of the bracelet also plays a role. The Rolex’s lug width is 21 mm. To me, the Rolex appears slightly unbalanced. A 22 mm or 24 mm would have been better suited for the Deepsea. For more info, please visit


Meor Amri Meor Ayob – Contributing Editor

Meor Amri is a passionate watch collector from Malaysia, Kuala Lumpur. Having bitten by the horology bug in 2010, he has written extensively about the watch scene and has assembled a large collection of watches (excessively!!) on his own free time. Read his articles here.

His blogs on the same subject are: Eastern Watch Western Watch