A Full-Grown Classic: Reviewing the Revamped Rolex Sea-Dweller

Rolex premiered its first divers’ watch, the Submariner, in 1953. The Sea-Dweller, which followed in 1967, had a nearly identical design. But since it was made for professional divers, it had an even more pressure-resistant case and a helium valve developed by Rolex. Rolex released a new model in 2017 to celebrate the Sea-Dweller’s 50th anniversary. It replaces the previous version, which debuted in 2014.

Rolex Sea-Dweller - soldier

The changes are unusually numerous and extensive for Rolex. The red letters that spell out the name “Sea-Dweller” recall their counterparts on the original model. Rolex’s improved manufacture Caliber 3235 is used here for the first time in a sporty model. The most noticeable changes are the larger diameter of the case, which has grown from 40 mm to 43 mm, and the “Cyclops” magnifier in the crystal above the date. This lens had never been included on any previous Sea-Dweller.

Purists may criticize the fact that the Sea- Dweller now comes with a magnifying lens because this model never had one in the past. Along with the significantly enlarged case, this results in a change that clearly exceeds the cautious modifications that Rolex customarily undertakes in its models and that are the reason for the constant value of vintage Rolex watches. On the other hand, changes have never harmed the Sea-Dweller. Both the new model and its predecessor, which had not been a bestseller, are now eagerly coveted and are trading at prices far above the manufacturer’s retail price.

The new model’s design is successful, too. It now looks more like a larger version of the 40- mm-diameter Submariner, which is actually not a drawback. In fact, this newcomer is even more convincing with a full set of minutes strokes along the divers’ bezel and its name printed in red letters below the dial’s center. Rolex lavished greater attention on the proportions here than on the Deepsea and the Submariner. The lugs are narrower, which makes the case look more elegant and less angular. This is also true for the bracelet, which appears somewhat narrow on the Deepsea, but is comparatively broader and, therefore, has a more harmonious look on the new Sea-Dweller.

Rolex Sea-Dweller movement CU

The height (15 mm) is a good match for the diameter. The Deepsea looks bulky by comparison and the Submariner seems almost too slim for a sports watch. All in all, the new Sea-Dweller is a contemporary and handsome interpretation of a Rolex divers’ watch.

Functionally, the new Sea-Dweller stays loyal to itself. The watertightness remains 1,220 meters. Needless to say, the case is equipped with a helium valve, although this feature is really necessary only for professional divers who decompress inside a pressurized chamber when engaging in saturation diving. In these conditions, a divers’ watch is surrounded by the gaseous breathing mixture, which contains helium. Under pressure, helium atoms can diffuse through a watch’s insulators and penetrate into its case, from which they cannot escape afterwards. This problem affected watches worn by divers in the U.S. Navy’s Sealab program, which was designed to research the effects that high pressure and various breathing gases have on humans. When the pressure was reduced in the decompression chamber, the crystals of these watches flew off. One of the Sealab divers told Rolex about this problem and suggested including a valve to release excess pressure by allowing helium that had penetrated into the case to escape without causing any damage. Rolex accordingly developed the helium valve, which many brands later included in their own watches.

Rolex has collaborated with Comex, the French diving specialists, since the early 1970s. Rolex supplied the watches for all Comex divers, who shared their professional experiences and helped further evolve Rolex’s watches. Comex lays undersea cables, performs underwater work on oil platforms, and can raise sunken ships. In the course of these adventurous tasks, Comex developed the necessary tools and experimented with various blends of breathing gases. Comex set numerous records for diving depth – and Rolex’s Sea-Dweller shared the ordeals because it was always strapped on the divers’ wrists.

Some of Rolex’s advertisements for the Sea-Dweller called attention to these record-setting achievements. For example, two divers spent 50 hours inside a pressurized chamber at a depth of 610 meters in 1972. Comex deep-sea divers subsequently plunged to beyond 500 meters’ depth. And a Comex diver descended to a depth of 701 meters inside a pressurized chamber in 1992. Comex really needed the Sea-Dweller’s helium valve and its greater pressure resistance (to a depth of 610 meters at the time) compared to the Submariner.

Rolex Dive Watches
Rolex’s three divers’ watches (from left): Submariner, Sea-Dweller and Deepsea. The new Sea-Dweller’s narrower lugs are clearly discernible in this comparative view.

Like the Submariner, which had been enlarged shortly before, the Sea-Dweller still measured 40 mm in diameter in 1976. The Submariner was equipped with a magnifying lens above the date in 1966, but the Sea-Dweller made do without this lens. Rolex replaced the Plexiglas with a sapphire crystal in 1978 and doubled the pressure resistance to 1,220 meters.

The Sea-Dweller Deepsea, with a diameter of 44 mm and pressure resistance to 3,900 meters, replaced its little sister in 2008. Not until 2014 would Rolex launch the new Sea-Dweller 4000 in a 40-mm case that remains watertight to 1,220 meters and bears a new ceramic dive-time scale on its bezel. This model didn’t sell very well, partly because it was significantly more expensive than the Submariner. After just three years on the market, it is bowing out and is supplanted by the larger Sea-Dweller.

Rolex not only optimized the proportions of the Sea-Dweller, it also improved other small details. For example, the luminous dot on the bezel is once again inset into the surface. This flush positioning makes the dot less likely to be knocked off if it comes into hard contact with a door frame or other object.

Legibility was already very good, so there wasn’t much room for improvement. Rolex’s “Chromalight” luminous material glows very brightly, so the displays are also clearly legible in twilight. The bluish color looks cool and doesn’t cause eyestrain. The triangle at 12 o’clock and the rectangular indexes at 6 and 9 assure instantaneous orientation. The zero index on the bezel also glows brightly. A luminous dot on the quickly moving seconds hand confirms in the dark that the watch is still running.

Rolex Dive Watches - buckles
Rolex has adjusted the width of the bracelet to the new size of the Sea- Dweller (near right). The bracelet of the smaller Submariner (far right) is much narrower.

Wearing comfort is good, too. Credit for this is primarily due to the case’s smooth back, the smooth underside of the folding clasp, and the supple steel bracelet. The individual links in this bracelet are curved so they can comfortably conform to the contours of the wrist. The spaces between the individual links remain unchanged in width even when the bracelet is bent sharply, thus assuring that they never pinch or tug at the hairs on the back of the wrist. The Glidelock clasp is solidly built and lets the wearer finely adjust the bracelet’s length. This ensures a quick and welcome dose of fresh air when the wrist expands on a hot day or after athletic exertion. Furthermore, the Fliplock extension lets the wearer add up to an additional 26 mm to the bracelet’s length. This means that the watch can be worn over the sleeve of a diving suit – a feature that the Sea-Dweller shares with the Deepsea, but which is lacking on the Submariner. The extension is visible on the Sea- Dweller because it protrudes from the clasp, being longer than an ordinary link in the bracelet. If the owner isn’t a diver and doesn’t like this feature, he can simply have the extension removed.

Opening the clasp accidentally is prevented by the safety bracket and its underlying rocker, which is easy to lift. But the clasp is still easy to operate, as is the readily grasped crown and the bezel, which clicks into each of its notches with smoothness and authority. The craftsmanship is impressive here, as it is throughout this well-made watch. The sides of the bracelet and the clasp are polished; the upper surfaces are satin finished. This combination of polishing and satin finishing likewise distinguishes the case.

Most potential purchasers opt for the Sea-Dweller because of its external characteristics, but Rolex nonetheless made some improvements inside the case. The Sea-Dweller is the first Rolex sports model to encase new Caliber 3235, which replaces Caliber 3135. Rolex initially deployed the new generation of calibers in precious-metal models (the Day-Date 40 and the Datejust Pearlmaster 39) in 2015, followed by the bicolor Datejust 41 in 2016. In 2017, Rolex encased this movement in the steel Datejust 41 and thus in models without any gold components in their cases.

Rolex Sea-Dweller - back
The caseback is smooth and the steel bracelet is supple for wearing comfort.

Caliber 3235 is an improved movement based on its predecessor (Caliber 3135), which was already known for high precision, robustness and longevity. More than 90 percent of the components underwent changes. Rolex was granted 14 patents for this caliber.

How does all this benefit the wearer? The shock resistance and reliability have been increased. The winding mechanism works more efficiently and more quickly amasses the full power reserve, thanks in part to the now ball-borne rotor. Most importantly, the maximal power reserve has been lengthened from the usual 49 hours to a long-lasting 70 hours. Rolex achieved this by making the wall of the barrel thinner, thus leaving more space inside the barrel to accommodate a longer mainspring, and by installing the innovative “Chronergy” escapement, which enables the Swiss lever escapement to operate with 15-percent greater efficiency. This boost is made possible by an altered geometry and a skeletonized shape that reduces weight.

Magnetic fields do not affect the escape wheel, which is manufactured from a nickel-phosphorous alloy via the LIGA process (lithography, electroplating and molding). The new balance staff likewise provides better protection against magnetic fields. The blue Parachrom hairspring, which is made from a niobium-zirconium alloy, will be a familiar sight for aficionados, who will have seen it in other Rolex models. These connoisseurs will also recognize the Paraflex shock absorption. Rather than the earlier two screws, only one screw is now used to adjust the vertical play of the balance. The hairspring’s uniform “breathing” is assured by the Breguet terminal curvature of this crucial spring. Index-free fine adjustment of the rate is accomplished by turning Microstella nuts along the inside of the balance’s rim.

Like the calibers inside all Oyster models, this one is hidden behind an opaque steel caseback. But despite its concealment, it has been handsomely embellished. These adornments include a sunburst on its partially skeletonized rotor and a second sunburst on the bridge for its automatic-winding mechanism, brushed matte surfaces on steel components, beveled edges on several at parts, and polished heads on the screws.

In 2015, Rolex introduced stricter rules for the fine adjustment of all its models. In addition to the chronometer certificates awarded by the Swiss authority COSC, Rolex’s watchmakers finely adjust each movement after it has been encased to ensure that it keeps time with even greater accuracy than COSC requires. Rolex tolerates a daily rate deviation of no more than –2 or +2 seconds. This performance is measured by a system that simulates real wearing habits.

Rolex Sea-Dweller escapement
The new Chronergy escapement has a higher degree of efficiency and allows for a longer power reserve.

These efforts do indeed pay off. Our tested Sea-Dweller gained only half a second per day on the wrist. It also stayed well within Rolex’s narrow tolerances when measured on the timing machine, where the average calculated deviation was a sensationally small gain of just 0.2 second per day. The greatest deviation among the several positions needn’t hide its head either: a gain of 4 seconds is a respectable performance, but not quite exceptional enough to earn the full complement of points in our grading system.

Thus far, everything argues in favor of the new Rolex. But what about the price? The new Sea-Dweller costs $11,350, which is substantially more than its predecessor. The higher price puts this debutante quite close to the Deepsea, which sells for $12,050, and even farther away from the Submariner Date, which retails for $8,550. The higher price is at least partially justified by the new movement and the case’s larger diameter. But a Submariner at $7,500 or a Datejust 41 at $7,350 could boast a better price/performance ratio.

On the other hand, a watch lover can count himself lucky nowadays if he can find an opportunity to purchase a Sea-Dweller at the regular price. The authorized jewelers keep waiting lists. And anyone who wants to buy a Sea-Dweller without waiting must look elsewhere. The good news: Supply doesn’t exceed demand quite as drastically as it does for the Daytona, and the imbalance is likely to become less extreme as time goes on. If you can buy a Sea-Dweller from a reputable jeweler after having waited a few months, you can be heartened by the greater value of your new watch – an increase that naturally also puts the high price into a flattering perspective.

The new Sea-Dweller is Rolex’s most handsome and most technically advanced divers’ watch. It offers the best combination of functionality and suitability for daily use. And with its new movement, it runs for three rather than only two consecutive days without requiring a fresh dose of energy. It costs a bit more, but this is outweighed by the nearly 100-percent likelihood that it will continue to increase in value. By gaining a magnifying lens above its date display, the Sea-Dweller may not have remained entirely loyal to its own tradition, but the fact remains that this new model is not only the best Sea-Dweller of all time: it’s also Rolex’s best divers’ watch ever.

Manufacturer: Rolex SA, Rue François-Dussaud 3–7, CH-1211 Geneva 26, Switzerland
Reference number: 126600
Functions: Hours, minutes, seconds, date
Movement: Manufacture Caliber 3235, automatic, chronometer, 28,800 vph, 31 jewels, stop-seconds function, rapid-reset mechanism for the date display, Paraflex shock absorption, Glucydur balance with Microstella adjusting nuts, Parachrom hairspring with Breguet terminal curve, Chronergy escapement, 70-hour power reserve, diameter = 28.5 mm, height = 5.37 mm
Case: Stainless steel, unidirectionally rotatable bezel with ceramic scale, slim, non-antireflective, sapphire crystal with magnifying lens above the date, screwed crown, fully threaded screw-in back made of stainless steel, water resistant to 1,220 m
Bracelet and clasp: Stainless steel, secure folding clasp with finely adjustable divers’ extension
Rate results (Deviation in seconds per 24 hours):
Dial up: +2
Dial down: +1
Crown up: -2
Crown down: +1
Crown left: +1
Crown right: -2
Greatest deviation: 4
Average deviation: +0.2
Average amplitude:
Flat positions: 286°
Hanging positions: 252°
Dimensions: Diameter = 43 mm, height = 15 mm, weight = 194 grams
Price: $11,350

Bracelet and clasp (max. 10 points): Outstandingly well-crafted steel bracelet and secure clasp with finely adjustable divers’ extension 9
Operation (5): Thanks to rapid reset for the date display and a stop-seconds mecha- nism, everything can be quickly set via the screwed crown. Very hand- some; the rotatable bezel clicks into each of its settings with satis- fying smoothness and authority. 5
Case (10): Very well-crafted and highly pressure-resistant case with scratchproof bezel 9
Design (15): The Sea-Dweller now looks like a large Submariner, but it o ers harmonious proportions. The magnifying lens is a matter of taste. 14
Legibility (5): Extremely legible thanks to high contrast and plenty of luminous material. 5
Wearing comfort (10): Despite its large size, this watch is very comfortable on the wrist. The steel bracelet is optimally shaped. 10
Movement (20): Well-engineered manufacture caliber with freely “breathing” Rolex hairspring and various improvements, including a new escapement and a longer-lasting power reserve. 19
Rate results (10): The average deviation is very small and the values in the several positions aren’t too far apart. 9
Overall value (15): A rather high price compared to the Deepsea (which offers a more elaborate case) and to the Daytona (which encases a much more complex chronograph movement), but if you can get your hands on this model, you’ll almost certainly be able to resell it at a higher price. 13
Total: 93 Points

Photos by Marcus Krüger / Movement picture by Rolex





No Responses to “A Full-Grown Classic: Reviewing the Revamped Rolex Sea-Dweller”

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  1. Jose Rosado

    Is their a mark 1 version Of the sea dweller? And will it be worth more in value?

  2. The writer does a great job of describing this beauty. I just bought a pre-owned SeaDweller with the Red Letters. Jens said a feature was cool, to me the entire watch is cool, beautiful and as a guy with large wrists I love the 43mm case size. I bought an Hublot 45mm not that long ago. 5 years ago could never imagine buying watches this size, but now completely changed my tune. As far as this modern Sea-Dweller, bravo Rolex, Bravo.

  3. Stephen Ledesky

    I love the sea dweller, right now I’m hooked on the submariner, I will purchase one second hand, for now, and evenually purchase a new one,

  4. Baltazar de la cruz

    Where I can purchase this sea dweller Rolex? I am really interested to buy.

  5. Unfortunately, I must correct you in your article on one crucial point: The US Navy and the Sealab divers had no part with the design or request of the Helium Escape Valve. That was all down to COMEX. They partnered with Rolex to come up with the gas escape valve for the Sea-Dweller and Rolex built less than 100 prototypes that were tested by Comex. They were rated to 500 Meters.

  6. Behealthis.Com

    Astoundingly, the watch only gains or loses -2 to +2 seconds a day, which goes to show you that Rolex finds it mandatory to be the best.

  7. Mark Chona Jr

    Beautiful watch. I am a proud owner of an incredible timepiece. Way to go Rolex.

  8. Genghbotkhan

    Turned one down. Didn’t see any real differentiator to my 16600. Was too big on my skinny wrist and expensive plu

    for what it is. Plus i am not a cyclops fan. I imagine it sold to the next client on the AD’s call sheet.

  9. John H Hill

    I bought mine in 2017 and have never worn it or removed factory stickers. It is a work of art and beautiful. A real investment piece which I really want to wear. Maybe I will. A master piece…….

    • Nothing has been mentioned with the differences between the 2017 1st gen and the newer 2nd gen with the crown @ the 6pm position on rhe watch face. Which one would more likely increase in value more?

  10. Great collections for watches really like these all Products thanks for sharing with us.

  11. Wayne silva

    One thing that was left out on this article.
    Resale is beyond good. I will not bad mouth any watch on line. A little over a ago I bought two watches same brand. A divers watch and a GMT. Several months later I sold them. I could not even give them away. I cried.
    My First Rolex my dad gave me in 1967 a Rolex GMT. I was in Jr. High school. In fact I have a Rolex GMT on my wrist right now. I can’t explain what it is. Nothing feels the Same on my wrist as a Rolex.

  12. Steve Pecoraro

    I Love the new Sea-Dweller but 12K with tax, I dunno?? For sure couldn’t tell the wife!!

  13. Sylvio Bertoli

    I have all the latest SD. I like this new one but it is a heavy time piece and I still could not get used to the idea of a SD having a cyclops. The watch looks very nice though and I get a lot of compliments for it.

  14. Whitney J Broussard

    Love mine. It’s like a large Sub to only better! Very comfortable. Perfect Watch

  15. David Reed

    Awesome review…well done. Answered all my questions…Will this be in a upcoming WatchTime magazine that I can buy soon?

  16. Mr. Tomato

    Absolutely LOVE this watch. Found one at my local AD and can’t stop wearing it. It’s so perfect from the inside out especially size wise. Congrats Rolex

  17. Hey
    Thanks for review!

    Dial on Submariner are made of gold, so what about in Deep sea?
    Contain Deep Sea any gold inside or outside?

  18. Debashish

    This Rolex is truly a super-watch. It is one of the finest divers’ watches in the world, if not the finest.

    Well, it goes without saying that I am Rolex lover.

    Enjoyed the review immensely, thanks!

    I am a proud Rolex owner and own quite a few Rolexes, yet I just cannot stand the attitude of some of the current Rolex dealers. Hope the present Rolex CEO and his team take some step in this regard.

    • Giovanni

      Rolex is definitely addressing this issue through ongoing retailer training. They have just started a new round of AD sessions that include extensive discussion regarding customer interaction, especially dealing with product in extremely short supply.

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