The Rolex Sea-Dweller

Rolex’s reputation has been forged on their relationship with the sea. It has been their obsession from the beginning and led first to the creation of the Oyster case, the innovation that changed the direction of the wristwatch as we know it.

From that day in the 1920s, the company continued to make huge strides, the next major landmark being the Submariner in 1954. Seen as almost the perfect watch, it was stylish enough to be worn for any occasion, while being more than tough enough to join underwater adventurers in the new sport of recreational Scuba diving.

Over the subsequent decade however, the world of diving graduated from being a diversion practiced in vacation’s relative shallows to the gritty, dark and abyssal depths of commercial operations.

Industrial saturation diving required something more than even the Sub’s impressive capabilities. Crews were sent to work far beyond the limits of the hobbyists, down to the crushing pressures of the ocean’s oil fields, often for weeks at a time. Known as one of the most hazardous jobs in the world, the reliance on equipment is absolute.

This was the arena that created the Sea-Dweller.

Rolex Sea-Dweller COMEX

In 1961, Frenchman Henri Germain Delauze formed the Compagnie Maritime d’Expertises, or COMEX. Specialists in undersea engineering, the company has pioneered much in the way of modern diving technology and is still among the leading names in the field today. It was COMEX that first identified a problem peculiar to the dive watches of the 60s.

The gas mixture used by divers during very deep operations is rich in helium, necessary to offset the narcotic effects of nitrogen and toxic effects of oxygen when both are put under great pressure. Helium molecules are some of the smallest of any element, and easily seep in through the seals of even the most robustly-built watch. Not a big problem while watch and diver remain at depth, but on the ascent back to the surface the helium bubbles would expand and blow the crystals off the face of the watch, sometimes with alarming force.

This was the problem COMEX brought to Rolex; to build a watch that was not only hard-wearing enough to survive the demands of the extreme work they were involved in, but also the trip back to dry land.

Rolex Sea-Dweller 1665

The solution Rolex devised was actually a co-creation with fellow Swiss brand Doxa, best known even then for their sports and dive watches. They called it the Helium Escape Valve, or HEV. Essentially a small, one-way regulator fitted into the side of the case at the nine o’clock position, it would allow helium to leach back out of the watch’s interior as it expanded and before it could cause any damage.

The first HEV’s were retrofitted onto the era’s non-chronometer Submariner, the ref. 5513 (making it the ref. 5514, and never commercially released).

After successful field testing, Rolex came up with an all-new design, with the escape valve built-in from the beginning, specifically intended as the ultimate in professional dive watches.

The Sea-Dweller ref. 1665 had a larger case and thicker crystal than the Sub, and with its Triplock crown, was rated to an incredible 2,000ft.

Rolex Sea-Dweller Ref. 16660

Those abilities put it leagues ahead of anything that had come before, talents that have only increased over the last half a century—doubled, in fact.

Since the late 1970s, the Sea-Dweller has been waterproof to 4,000ft, and the range continues to pioneer new technologies.

While its basic styling might be easily recognizable as cut from the Submariner cloth, the Sea-Dweller has always stuck to its original remit.

It is a long time since anyone has bought a Sub for the sole purpose of diving. Rolex conceded to it being far more status symbol than tool watch generations ago and have released evermore luxurious versions in gold and Rolesor, with color schemes designed for catching the eye across a boardroom table or crowded bar.

The Sea-Dweller remains all business. With a palette of nothing but the highest contrast black and white, and forged only from the strongest steel, it is the absolute blueprint of exactly what a dive watch should look like and be capable of. It is the one that merges optimum performance with the most day to day wearability.

Below we’ll take a detailed look at how you can take possession of arguably the coolest watch in the Rolex stable.


There are some fantastically rare examples of the Sea-Dweller, small handfuls of watches that debuted its new features, essentially little more than working prototypes distributed to professional diving crews for testing and never meant to be made available to the general public. These of course have since leaked out and crop up occasionally on the vintage market, changing hands for incredible sums of money.

If they represent the very top end of the scale, easily going into six-figure territory and beyond, at the other extreme, membership fees to the Sea-Dweller club aren’t a million miles away from those of the Submariner.

Expect to pay about 10% more for the entry point Sea-Dweller against the date-equipped Sub (the little brother has both date and no-date versions; the Sea-Dweller has only date models).

Mens Rolex Stainless Steel Sea-Dweller Black 16600

Prices start at around the $7,000 to $8,000 mark, and for that you can own a pre-Cerachrom bezel ref. 16600, from the longest running series that started in 1988 and took the watch all the way up to its brief retirement in the late 2000s.

The next bracket up, but not by a long way, is the second iteration from 1978, the affectionately nicknamed Triple Six, or ref. 16660. This was the first to venture down to 4,000ft, and brought with it a larger HEV and the high beat Cal. 3035 with its 28,800vph frequency.

Perhaps the best value reference in terms of future investment potential is the fleeting ref. 116600. This was the comeback kid from 2014 after Rolex had unexpectedly discontinued the model six years earlier to make way for the enormous Deepsea. It made a triumphant return sporting a new ceramic bezel and beefier Maxi case, and the brand faithful were in raptures.

However, the celebrations were short-lived. In 2017, the Sea-Dweller’s 50thbirthday, the ref. 116600 made way for the current ref. 126600, with its unheard of 43mm dimensions and, horror of horrors, the first Cyclops the series had ever seen.

Rolex’s magnifying lens has been splitting opinion since it was introduced on the Datejust in 1954, with detractors complaining it ruins the symmetry of the dial. It was never fitted to the Sea-Dweller before as the enormous pressures the watch was designed to work at would have broken it, and a large proportion of the SD’s fans have long been made up of those who chose it specifically over the Submariner precisely for its lack of Cyclops.

Rolex Mens Sea-Dweller Stainless Steel 116600

The previous generation, the ref. 116600, has therefore become an attractive target for collectors due to both its limited production run and the fact it is the last iteration without the lens. Handing over the starting price of around $12,000, around the same as for a brand new model, could be a move that pays dividends quite soon.

Obviously, as with all things Rolex, it is the earliest examples of a series that are generally the most expensive, and in the Sea-Dweller’s case that means the legendary ref. 1665. Within that one reference are enough different variations to fill a book; watches with fabled nicknames such as the Single Red, Double Red, Great White and so on, and we will look at them in more detail later on. Needless to say, securing yourself one of the first run ref. 1665’s can put a severe dent in your net worth.

The Options

Underlining its pure tool watch credentials, the Sea-Dweller has the least number of options of just about any model in Rolex’s catalog, bar the Air-King or the original Explorer. And by that, we mean none.

Even the perpetual underdog pieces, second stringers like the Explorer II or the Milgauss, are given a choice of dial color. Icons such as the Daytona or the GMT-Master have legions of alternatives.

With the Sea-Dweller, it is very much a case of Rolex picking the arrangement that works the best for the job it was designed to do, and not seeing any point in deviating from it.

That means no precious metal bodywork; it’s the toughest stainless steel or nothing. The originals were forged from 316L before progressing through to the insanely strong 904L which is pretty much the sole preserve of Rolex watches, what they have now rebranded as Oystersteel.

Rolex Sea-Dweller 116600

The bracelet is restricted to the most utilitarian offering, the three-link Oyster, which has itself evolved over the years from the relatively flimsy hollow links to the more modern solid link type. Since the ref. 116600 from 2014, it has also been fitted with the brand’s patented Glidelock and Fliplock extension systems, to allow fast adjustments to be made without the need for tools.

And the dial can be any color, so long as its black. For a dive watch meant primarily for the most demanding professionals, legibility is paramount, so the Sea-Dweller has only ever had a black face with white indexes. The handset has never been anything other than Rolex’s trademark Mercedes style, and they, as well as the mix of circular, baton and inverted triangle hour markers, have always been drenched in lume.

All told, it leaves it an effortlessly stylish yet seriously-minded watch, and a world away from the Submariner’s golden getups and brightly colored options.

The Sizes

In a similar vein, each generation of the Sea-Dweller has been available in only one size. Unlike models such as the Oyster Perpetual range, or even the latter day Datejust or President, you are given no choice in dimensions.

Rolex Sea-Dweller 126600

The original was released in 40mm, relatively large for the era, but ideal for a high performance tool watch designed to be easily read in difficult and sometimes stressful conditions.

That was the size Rolex stuck with for the first 50 years of the production run. Then, to the surprise of everyone in 2017, the anniversary edition arrived sporting a new 43mm case, putting the Sea-Dweller within a whisker of the gargantuan Deepsea, the largest of the brand’s dive trio.

It was an unexpected move, but one which has been welcomed by many, particularly with modern trends towards bigger watches. It also worked to differentiate the Sea-Dweller from the Submariner, with younger enthusiasts starting to grumble that the Sub’s 40mm is just a little on the small size for a contemporary diver.

But any iteration of the SD can still pull off the party trick of being more than robust enough to descend to depths far beyond the realistic for the vast majority, while still being able to hide away discreetly beneath a shirt sleeve when it needs to.

It is an incredible achievement for a watch that can survive a plunge to three quarters of a mile underwater.


COMEX’s initial brief for the Sea-Dweller was for a watch their crews could put their complete trust in in perhaps the most demanding environments on earth. Commercial saturation diving is extraordinarily dangerous and every element of kit has to be as reliable as it is possible to be.

With Rolex’s long history of building the most accurate and durable timepieces in the industry, they were the obvious first port of call.

Decades of engineering prowess ensured making a watch capable of keeping the water out, even at the tremendous depths the divers were working at, was comparatively simple. The real problem was helium.

Rolex Sea-Dweller 1665

There is really no substance in the world that can prevent the ingress of helium molecules under pressure—not even an Oyster case. So if it was unavoidable for the gas to get into the watch, the solution was to create a method for it to get out again safely.

The HEV is Rolex at its most elegantly ingenious. A one-way, spring-loaded valve, it was simply designed to open once the pressure inside the watch became greater than the ambient pressure outside. Essentially, it meant the watch decompressed at the same time as the diver.

Not only did it work perfectly, it also allowed for the Sea-Dweller to retain the classic Rolex looks.

Beyond that unique capability, the watch followed the same pattern of gentle evolution as the rest of the brand’s lineup.

Rolex Caliber 1575

Calibers came and went as advances were made to their technology. The original, the Cal. 1575, was given a hacking function a few years into its run, providing the ability to stop the seconds hand while adjusting the time for greater accuracy. That movement was replaced by the Cal. 3035 inside the Triple Six in 1978 which brought with it not only the high beat frequency of 28,800vph, the speed of all Rolex watches ever since, but also the convenience of a Quickset date feature. It meant the day of the month in the three o’clock window could be changed by turning the crown, rather than having to wind the hands through 24-hours.

New materials have been introduced into the mechanisms in recent times, all with the sole aim of improving timekeeping precision.

Rolex Caliber 3235

The Parachrom hairspring arrived in 2000, made up of niobium and zirconium and treated with an oxide coating. It offers up to 10 times more shock resistance than traditional materials and is completely antimagnetic. Since 2005 that coating has been made thicker, causing the spring to turn a distinctive blue color once it reacts with the air, and leading to the component being rechristened the Parachrom Bleu.

The latest model has been granted an all-new caliber, the Cal. 3235, with the heavily reworked Chronergy escapement, a stripped down and hyper efficient module made from nickel phosphorous, affording the movement even greater safeguards.

Although the name may have been around for half a century, the Sea-Dweller still stands at the pinnacle of what is possible with modern watchmaking flair.


With the possible exception of the Daytona, the Sea-Dweller is feasibly the most collectible of all vintage Rolex.

There are, very theoretically, only five references of the watch, but that narrow band houses the sort of variations that can make differences in price measured in the hundreds of thousands of dollars.

Going in order, starting at the most costly, is the Single-Red. These are the prototypes Rolex distributed to a tiny number of handpicked professional divers for testing before the watch was put into production, and never made available to the general public.

So nicknamed for the single line of red text on the dial, reading ‘Sea-Dweller’, they also redefine the word rare—there are only about a dozen still in existence. Most of these early watches are actually without the helium escape valve, and they all have a depth rating of 500m on their dials rather than 600m. Considered the holy grail of all dive watches, a fully correct version would likely break the million dollar barrier at auction.

Next up are the Double Red Sea-Dwellers which, as you have probably guessed, have two lines of red text, in this case ‘Sea-Dweller’ and underneath, ‘Submariner 2000’.


Commonly known as the DRSD, there are thought to be at least seven versions. The most valuable remain the first run pieces, sometimes identified as the ‘Patent Pending’ models. Rolex released the watches having filed for the HEV patent but had not as yet received it, and so the case backs are engraved with the two words.

The DRSDs were in production for 10 years and went through a number of changes to the dial or crown, many of which are so minor you would need a loupe to identify them. However, dedicated collectors live for these minute inconsistencies, or rather, the comparative scarcity of each. Of them all, dials Mark I-III are the most sought after, Mark IV the most common, while Mark V, VI and VII are usually service replacements.

In the late 70s, Rolex continued with the same ref. 1665 model, but did away with the red text. These follow-ups came to be called the Great Whites and were essentially unchanged except for the uniformly white lettering. However, they generally sell for much less than the Double Reds.

Rolex Mens Submariner Comex Ref. 5514

Again, there were a number of versions released, with some more prized than others. The Mark II dial is about the most coveted of the publically available pieces, what aficionados call the ‘rail dial’. It describes the alignment of the two lines of text—‘Superlative Chronometer’ and ‘Officially Certified’—where the two Cs line up one above the other.

Another stunningly rare type from the Great White category are the COMEX dials. A handful of these models, around 300 or so, were made to order exclusively for employees of the diving outfit and with the company name printed on the dial at the six o’clock. Today, these command huge prices.

In 1978, Rolex launched a new edition of the Sea-Dweller, although they continued to make the Great White as well, and the two references ran side by side until the ref. 1665 was finally retired in 1983.

The updated model, the ref. 16660 or Triple Six, is seen as the first of the modern style. It debuted not only the 28,800vph caliber, but was also the first model to boast 4,000ft waterproofness and a sapphire crystal, replacing the plexiglass of earlier watches. It also introduced a larger HEV and a unidirectional bezel.

The Triple Six became a big favorite in the series, and a relatively high volume were produced during its 11-year run, making them a more attainable option on the vintage market. However, these too have a COMEX version, with even fewer being made than with the Great White, with that rarity reflected in the prices.

Rolex Sea-Dweller Ref. 16660

The most affordable reference is the next in the chain, the ref. 16600, which stayed around for some 20 years. It is practically identical to the later Triple Sixes but with a slightly improved caliber, the Cal. 3135. Again, there are around 200 special order COMEX pieces out there somewhere, the last time Rolex would supply the company especially, which very occasionally come up for sale.

As we said above, the blink-and-you’ll-miss-it ref. 116600 from 2014 would be our bet for a great future investment. The last 40mm non-Cyclops model, its three-year tenure was a popular one, but once word came through it was to be discontinued, pre-owned prices started increasing sharply. One to look at sooner rather than later.

Other outliers worth mentioning; there are a smattering of double-signed Sea-Dwellers from the 1970s, sold through the highest of high end retailers such as Tiffany & Co. or Cartier. These have the store’s name on the dial alongside Rolex. While not impossible to find, many collectors can go their whole lives without seeing one in the flesh.

And possibly even more uncommon are the pieces Rolex made for the Sultan of Oman and his royal associates. These have most of the dial text replaced by the country’s national symbol, the Khanjar. Experts believe there are around 100 of these in existence, the emblem in either red or green.

The Rolex Sea-Dweller Timeline

The Rolex Sea-Dweller started life in 1967 following a direct request from French commercial outfit COMEX for a watch that could withstand the rigors of saturation diving.

Taking the Submariner as a base, Rolex fitted it with a new type of valve designed to off-load built up helium, which made up a large portion of the gas their crews breathed deep underwater and which would seep inside their watches. During ascent, the helium would expand and, in some cases, cause the dial covers to explode.

With the Helium Escape Valve (HEV) in place, further strengthening of the case and adding a domed plexiglass crystal saw the inaugural Sea-Dweller rated waterproof to 2,000ft, far ahead of anything else available at the time.

Rolex Sea-Dweller 1665

The first production run of the debut reference, the ref. 1665, came to be known as the Double Red Sea-Dweller, or DRSD, for their two lines of red dial lettering. Ten years later in 1977, all dial text was changed to white and the nickname likewise switched; the final examples of the ref. 1665 were given the moniker The Great White.

Released in 1978 and running concurrently with the Great Whites, the ref. 16660 proved a radical upgrade for the Sea-Dweller. These models, called the Triple Six by collectors, featured a larger HEV along with a thicker case, topped with a strong sapphire crystal. The developments doubled the watch’s water resistance to 4,000ft and the Triple Six stayed in production for 11 years.

In 1989 the longest running reference of the Sea-Dweller emerged, the ref. 16600. Ostensibly the same as the former model, it was granted an improved movement, the Cal. 3135, with a longer power reserve and a full balance bridge rather than the balance cock of previous calibers.


The ref. 16600 took the Sea-Dweller up to 2008 when, in a shock move, Rolex discontinued the watch to make way for its new take on the ultimate dive watch, the Deepsea. Using a unique three-part case construction, the huge 44mm wide, 17.7mm thick model was rated down to some 12,800ft underwater.

While it proved reasonably popular, it was a little too niche for Rolex’s core fan base and, in 2014, the Sea-Dweller was reintroduced with the ref. 116600.

This brought the series’ first Cerachrom bezel and Maxi case, with thicker lugs and crown guards, and marked a jubilant return. However, it was to be little more than a transitional reference when in 2014, the 50thanniversary of the Sea-Dweller, it was superseded by the current model, the profoundly different ref. 12660.

As well as bulking up the body, from the time-honored 40mm to 43mm, it also gave the watch its first Cyclops lens over the date window. The movement is Rolex’s most advanced to date, complete with the Chronergy escapement, a component taking five years to perfect and protected by 14 patents.

The changes have brought the watch into the modern age, but whether contemporary or vintage, it remains one of the crown’s most enduringly popular creations. The perfect blend of incredible performance and aesthetic versatility, the Sea-Dweller continues to be in a league of its own.