What’s the Difference? The Rolex Submariner Vs. The Rolex Sea-Dweller

You would think that deciding on what was officially the first ever dive watch would be a fairly straightforward task, but depending on your point of view, the Omega Marine, or the Panerai Radiomir, or the Blancpain Fifty Fathoms can all stake a claim.

It’s a subject that causes much debate among watch nerds, but two things are generally agreed on. One, the Rolex Submariner was not the first, and two, regardless, it is still the model that most readily springs to mind when you hear the words ‘dive watch’.

The Development

Rolex, of course, had been pioneering ever greater waterproofing for their various timepieces for decades before the Sub put in its first appearance. The Oyster case, developed in the 1920s, had proved itself in environments once considered unthinkable for a wristwatch which, until then, had always been very much a fragile piece of jewelry worn almost exclusively by women.

With the Oyster’s impenetrable seals keeping not just water but also dust and humidity out of the delicate inner workings, the watch as an essential male accessory was born, winning its spurs on the battlefields of WWI.

The First Submariner

Between the wars, the Italian Navy recognized the need for a watch their elite diving unit could read in even the murkiest of waters. Their chosen supplier, Panerai, had long been utilizing the luminescent qualities of radium on their range of underwater instruments, unaware of its disastrous effects, and teamed up with Rolex on the project.

Vintage Rolex Submariner 6204
Photo: A Blog to Watch

The upshot of the collaboration, the Radiomir, used a Rolex Oyster case and Rolex movement and provided the inspiration for the brand to start producing dive watches of their own.

In the 1950s, the popularity of recreational diving took off, helped immensely by the invention of the aqualung by Émile Gagnan and a certain Jacques Cousteau who, by no coincidence whatsoever, was a close friend of one of Rolex’s board of directors, Rene-Paul Jeanneret. With Cousteau’s input, the first of the Submariners was made ready for its debut in 1953.

It was the birth of perhaps the single most iconic watch ever made. The ref. 6204, its design simplicity itself, had all the abilities to be the ideal dive companion, as well as the timeless good looks to be worn on just about any occasion and with any outfit. In short, it was the only watch you would ever need.

Rolex Mens Turn-O-Graph Two-Tone 6202

Over its now 60+ years of unbroken production, the materials and technology may have revolutionized, but its basic DNA is still instantly recognizable from that initial example. The 37mm case was inflated to 40mm by the end of the 50s and crown guards were brought in at the same time. Water resistance, originally 100m, improved first to 200m with the introduction of a bigger winding crown and eventually to the 300m we know today. A date window and a Cyclops magnifying lens were added, controversially, in 1969.

But it is the bezel that forever remains its most identifiable feature. Taken from the ref. 6202 Turn-O-Graph released a year before, sometimes known as the pre-Submariner, the rotatable surround with the graduated markings provided divers with a simple, reliable method of keeping track of their time underwater. For those Submariner customers who weren’t divers, i.e. most of them, it was a useful way of timing just about anything, while also providing a strong aesthetic element that made the watch stand out from the crowd.

Interestingly, it wasn’t until 1981, nearly 30 years later, that Rolex were able to give the Submariner the added safety precaution of a unidirectional bezel. Until then, the patent for it was held by Blancpain for their Fifty Fathoms model.

The Bigger Brother

The all-conquering Sub, then, could do no wrong. A genre-defining watch, shamelessly imitated by rival manufacturers and blatantly copied by forgers. First choice of James Bond, the Royal Navy and Steve McQueen (yep, not the Explorer II, honestly) it was responsible for making the dive watch the most popular type of sports watch, especially among those who did neither.

Rolex Mens Submariner Comex Ref. 5514

However, there was an elite group of individuals for whom a water resistance rating of 300m was never going to be enough. People who needed a dive watch for, of all things, diving.

In the 1960s, French commercial and industrial dive operators COMEX approached Rolex with a problem. Their crews were spending prolonged periods underwater at great depths, breathing a gas mixture that contained a proportion of helium to negate the effects both oxygen and nitrogen experienced when subjected to high pressures. With helium having some of the smallest molecules of any gas, the tiny bubbles were seeping inside their diver’s watches and, as they ascended back to the surface and the drop in pressure caused the bubbles to expand, the protective crystals covering the dials would be popped clean off, sometimes with extreme force.

The solution, in Rolex’s hands, was the Helium Escape Valve, or HEV. A small, one-way regulator set into the case at nine o’clock, it expelled the swelling gases safely and protected both watch and diver.

Taking a standard Submariner of the era (the model was up to the beloved ref. 5513 by this time), Rolex retrofitted it with their new innovation and sent it off to COMEX for testing. The renamed ref. 5514, a grail watch today if there ever was one, proved itself successful enough that it led onto the development of a purpose-built model, one suited to the extremes of saturation diving.

The Sea-Dweller

By 1967, the first of this new breed was ready. Quite clearly adopting the same design cues as the Sub, its thicker case and domed crystal, along with the HEV of course, set it as the more serious alternative to its smaller and older brother.

Rolex Sea-Dweller 1665

The ref. 1665, more commonly known as the Double Red Sea-Dweller (DRSD) for the two lines of red text on its dial, was rated good down to 2,000ft, more than doubling the Submariner’s resistance.

While both series’ have evolved over the last half a century, the Sea-Dweller’s upgrades have always been based on improving its already impressive functionality rather than positioning itself as a statement piece. So it has never succumbed to the allure of gold or Rolesor and has instead toughened up even more, its most recent all-steel iterations able to survive some 4,000ft underwater.

Though the Submariner’s variety has seen its fan base grow exponentially, with unorthodox examples in blue and green along with the precious metal versions that appeal across a broad spectrum, the Sea-Dweller has maintained an air of exclusivity. It has never sold in as great a number, but it has carved itself out a fiercely loyal following nonetheless.

That Damn Cyclops!

Along with its status as the more capable of the two, even though the likelihood of either watch being tested to its actual limit by the average wearer remains negligible, there was traditionally one more reason the Sea-Dweller has avoided being completely engulfed by the Submariner’s shadow.

When the first Sub with a date function emerged, the ref. 1680 from 1969, it launched with Rolex’s patented magnifying lens over its three o’clock window.

Known as the Cyclops, it had been unveiled on the Datejust in 1954, and has been the cause of huge debate ever since.

Without doubt a useful feature, it gives a 2.5x increase to the apparent size of the date numerals beneath but, in the eyes of many, ruins the simple symmetry of the dial.

Because of the depths the Sea-Dweller was designed to work at, and the subsequent crushing pressures inflicted on it, it had never been possible to outfit the watch with its own Cyclops, and its unadorned face was seen as the most aesthetically balanced of the two.

Until now.

Triggering equal parts joy and dismay, the latest Sea-Dweller reference, the 50th anniversary ref. 126600, appeared last year with a new 43mm shell, an all singing and dancing movement upgrade and, to the strangled cries of ‘sacrilege’ from some quarters, a big old bubble stuck on its crystal.

It has left the gargantuan Deepsea, the Sub’s even bigger bigger brother, as now the only date-equipped watch in the entire Rolex range with an unmagnified dial.

Although the Cyclops has always split opinion and will doubtless continue to do so, the Sea-Dweller’s newly increased dimensions mean it’s less of an issue than on the 40mm Sub. The extra millimeters give more surface area to play with, and the lens takes up a proportionately smaller amount of dial space. Love it or hate it, it doesn’t distract too much from what is a fantastically handsome watch.

So, Sub or Sea-Dweller?

The Submariner, possibly the most immediately identifiable watch ever made, has been with us now for more than six decades. That is a vast archive of treasures to explore, and it would be a rare person who didn’t find something in that back catalog to suit their tastes.

By comparison, the Sea-Dweller has always shunned the limelight and contented itself with a more utilitarian look, backed up by the formidable strength of its enhanced abilities.

Being forced to choose between them is not the worst problem in the world to have, to be honest, and is one of those times when you can’t really make a wrong decision.

The right choice is the watch that’s right for you, and whatever happens, you get to wear a genuine legend.