Water Resistance in Watches

Have you ever looked at your watch and wondered what "water resistant" truly means? It's far more than just a label on the back of a case. It represents a century and a half of groundbreaking innovation, daring human endeavor, and the relentless pursuit of precision in the most hostile environments on Earth: the deep oceans.

At Brigade Watches, we believe that understanding the legacy behind your timepiece enhances its value and your appreciation for its engineering. This week, we're taking a journey through time to explore the fascinating evolution of watch water resistance, from its earliest conceptual attempts to the high-tech marvels we see today.

The Foundational Principles: A Timeline of Water Resistance Innovation

To truly grasp how watches became masters of the deep, we must first examine their origins, the evolving needs, and the pioneering models that laid the groundwork. This isn't a story of a single invention, but a chronological progression of genius and necessity, evolving from rudimentary sealed timepieces to the robust wrist-worn tools we recognize today.

1. 1864: Alcide Droz & Sons "L'Impermeable" - The Invention of the Screw-Down Crown Mechanism

About The Watch:

Primarily a pocket watch, "L'Impermeable" ("The Impermeable") is widely regarded as the first truly attested waterproof timepiece. It featured a sealed case and a winding crown designed to be water-resistant.

Unique Contribution to Water Resistance:

The groundbreaking technological contribution was the invention and first attested implementation of the screw-down crown mechanism itself. This system works by incorporating threads on the crown that mate with corresponding threads on a tube extending from the watch case. When the crown is screwed down, it mechanically compresses internal gaskets (made of available sealing materials like leather, cork, or early forms of rubber) against the case tube. This direct, active compression creates a much tighter and more secure seal around the crown stem than was previously possible with simple friction-fit or push-pull systems, thereby significantly preventing water ingress through the most vulnerable opening on the watch.

2. 1921: Jean Finger Hermetic Case - Water Resistance by Full External Enclosure

About The Watch:

Swiss case maker Jean Finger introduced a patented design (CH 89276) that placed a complete watch-movement, dial, and crown-inside a larger, screw-down outer case with no external stem opening. Brands like Rolex, Zenith, Eberhard, and Marvin adopted this concept.

Unique Contribution to Water Resistance:

The groundbreaking technological contribution was its novel method of achieving water resistance by completely enclosing the entire watch within a secondary, external sealed case, thereby eliminating the crown stem as a direct point of water entry. Unlike other designs attempting to seal the dynamic crown stem, this system bypassed the problem entirely. The outer case itself was made water-resistant through screw threads, ensuring the complete inner watch compartment remained impermeable to water from all external points of contact with the primary timepiece.

                   

3. 1926: The Rolex Oyster - The First Practical, User-Operable Screw-Down System for Wristwatches

About The Watch:

While the concept of a screw-down crown existed prior (as seen in the 1864 Droz pocket watch, and patents by Perregaux and Perret which Rolex later acquired), the Rolex Oyster was a revolutionary wristwatch that refined and integrated this principle with unprecedented practicality. It featured a patented system integrating multiple screw-down components (bezel, caseback, and crown).

Unique Contribution to Water Resistance:

The truly unique technological contribution was the perfection and integrated implementation of a user-operable screw-down crown system for wristwatches that allowed for effortless daily winding and setting without compromising the seal. While earlier screw-down crowns existed, Rolex's innovation (based on acquired patents, notably Perregaux and Perret's) introduced a crucial clutch mechanism within the crown. This mechanism allowed the crown to rotate freely (without turning the winding stem) while being screwed down onto the threaded case tube. Only when the crown was unscrewed and pulled out did it engage with the winding stem, enabling time setting and winding. The primary seal for the 1926 Oyster crown was achieved by the compression of a gasket (likely metal, leather, or a similar material of the era) at the base of the crown against the case tube when fully screwed down. This ingenious combination of a reliable compression seal and a practical clutch system made robust, tool-free water resistance a viable and convenient feature for everyday wristwatches, setting the standard for future designs.

4. 1932: The Omega Marine - The Double-Case External Clamping Seal System

About The Watch:

This was one of the earliest wristwatches explicitly marketed and designed for actual diving. It notably accompanied explorer Charles William Beebe during a deep-sea bathysphere dive.

Unique Contribution to Water Resistance:

The unique technological contribution was its innovative double-case sealing system utilizing an external clamping mechanism. The inner watch case slid into a substantial, rectangular outer case. This outer case was then secured by a robust, spring-loaded external clamp that compressed the two case sections together, along with strategically placed cork gaskets (a notable choice for sealing material at the time). This design offered a highly effective and robust alternative method to achieve significant water resistance, independent of the crown's direct sealing mechanism, for dedicated underwater use.

5. 1953: The Rolex Submariner - The Evolution of Multi-Gasket Screw-Down Crowns (Twinlock & Triplock)

About The Watch:

Introduced in 1953, the Rolex Submariner quickly became the archetypal modern dive watch, defining the look and functionality for professional and recreational divers alike. While it built upon the foundational Oyster case technology, its enduring success and enhanced water resistance capabilities were significantly due to continuous advancements in its crown sealing system.

Image Credit: Watch Insanity  – "ROLEX SUB-AQUA 6204: THE RAREST SUBMARINER!" https://www.watchinsanity.it/en/rolex-sub-aqua-6204-the-rarest-submariner/

Unique Contribution to Water Resistance:

The Submariner popularized and showcased the significant technological evolution of the screw-down crown beyond the original Oyster's single compression seal. This involved the introduction and widespread adoption of the Twinlock crown in 1953, followed by the even more robust Triplock crown in 1970.

The Twinlock system dramatically improved water resistance by utilizing two sealed zones: typically one O-ring gasket placed on the inner side of the crown, compressing against the case tube when screwed down, and a second O-ring gasket directly on the external surface of the case tube itself. This created a much more robust and reliable double barrier against water ingress.

Image Credit: Bob's Watches – "Twinlock vs. Triplock: What’s the Difference and Does it Really Matter on a Rolex Watch?" https://www.bobswatches.com/rolex-blog/resources/twinlock-vs-triplock-whats-difference.html 

For watches designed for extreme depths, the Triplock system further enhanced this by adding a third sealed zone (an additional O-ring gasket, often visible externally or internally on the case tube). This multi-gasket approach, combined with more robust crown tubes and materials, allowed the Submariner and later the Sea-Dweller to achieve unprecedented depth ratings for mass-produced wristwatches, pushing reliable water resistance from hundreds of feet to thousands of feet, cementing the standard for serious dive watches.

                                 

Image Credit: Bob's Watches – "Twinlock vs. Triplock: What’s the Difference and Does it Really Matter on a Rolex Watch?" https://www.bobswatches.com/rolex-blog/resources/twinlock-vs-triplock-whats-difference.html 

These pioneering watches, from Droz's initial screw-down concept to Rolex's multi-gasket systems and Omega's innovative double-case, collectively laid the robust foundation for modern water-resistant timepieces. They pushed the boundaries of mechanical sealing to withstand the immense pressures of the aquatic environment. While earlier watches like the Rolex Submariner exemplified the highest widely achieved depth ratings of the era, performing admirably down to 200 meters (660 feet), as the mid-20th century gave way to unprecedented deep-sea exploration and the advent of saturation diving, new challenges emerged-challenges that required not just stronger seals against water, but entirely new solutions for the unique gaseous environments of deep-sea habitats. This is where a groundbreaking French company called COMEX (Compagnie Maritime d'Expertises) entered the scene.

Going Deeper: The Next Frontier in Water Resistance with COMEX

What type of company was COMEX?

COMEX was a French company specializing in commercial deep-sea diving and underwater engineering. Founded in 1961, they quickly became pioneers in advanced diving techniques, particularly saturation diving, for industries like offshore oil and gas. Their work involved complex underwater construction, maintenance, and exploration at extreme depths, often far beyond what recreational divers could ever achieve. They were essentially the world leaders in getting humans safely and efficiently to the deepest parts of the ocean for commercial purposes.

Image Credit: Abyss Scuba Diving – "Saturation Diver: Exploring the Depths of A Unique Craft" https://www.abyss.com.au/blog/a-career-in-diving/saturation-diver-exploring-the-depths-of-a-uni que-craft

Pre-COMEX Era (Before 1970s): The State of Depth Ratings

Depth ratings did exist before COMEX-but they were far less standardized and often more symbolic than technically verified.

Watches like the Blancpain Fifty Fathoms (1953) and Rolex Submariner (1953) were among the earliest to feature depth ratings-typically 100m to 200m. These ratings were largely based on static pressure tests in laboratories, not real-world saturation diving conditions. There was no universal standard for how depth ratings were measured or validated, and manufacturers often used them as marketing tools rather than strict engineering guarantees.

What are saturation habitats?

Imagine a high-tech submarine that doesn't move. These are like mini-apartments or pressurized chambers placed either deep underwater or on a specialized ship. Divers would live inside these saturation habitats for days or even weeks at the same high pressure as the surrounding deep water. This revolutionary technique allowed them to work for much longer periods at extreme depths without having to go through exhausting and time-consuming decompression stops every single day. They'd only undergo one long, slow decompression process at the very end of their multi-day or multi-week mission when they were finally coming back to the surface.

Why did COMEX need super tough watches and their own ratings?

Unprecedented Depths & Pressures:

Unlike combat divers from WWII who operated in shallower coastal waters, COMEX divers routinely worked at depths starting from 250 meters (over 800 feet). At these depths, the pressure becomes truly colossal; to understand this, remember that for every 10 meters (approximately 33 feet) you descend in water, the pressure increases by roughly 1 atmosphere (atm) or 1 bar.

Safety First:

When you're thousands of feet underwater, every second counts. Divers needed watches to accurately time their work cycles, their breaks, and most importantly, their slow, precise journey back to the surface (decompression schedules are unforgiving). Timing errors could have severe, even fatal, consequences from decompression sickness.

Beyond Normal Limits:

Regular watches, even the robust 200m models, simply couldn't reliably handle the crushing forces and the unique gaseous conditions of these extreme deep dives. The existing standards were insufficient.

So, COMEX worked directly with leading watchmakers (most notably Rolex, with their famous "COMEX" stamped dials on special Submariner and Sea-Dweller models) to create and rigorously test watches that could survive these brutal conditions.

What did COMEX changed?

COMEX demanded real-world performance, not just lab specs—so Rolex began rigorously testing watches under simulated saturation conditions, pushing the boundaries of what a wristwatch could endure.

The "depth ratings" you see on watches today (like 200 meters or 1000 feet) were heavily influenced by these demanding tests. For instance, the 610-meter (2,000 feet) rating became a critical benchmark: this was the original specification for the Rolex Sea-Dweller, a watch specifically engineered in 1967 for saturation divers working with COMEX. This extreme depth capacity was crucial because saturation diving in the 1960s and '70s was constantly pushing boundaries, requiring watches that could not only survive immense underwater pressure but also manage the buildup of gases like helium during the lengthy decompression process that followed.

The 610-meter rating isn't necessarily the average daily working depth for these divers (which typically ranged from 100–300 meters), but it represented a vital safe margin above those operational depths, ensuring unparalleled reliability even under the most extreme and unforeseen conditions. To put 610 meters into perspective, that's deeper than the height of the Empire State Building (443m / 1,454 ft) or nearly twice the height of the Eiffel Tower (330m / 1,083 ft)! At 61 atmospheres, the pressure is staggering: it's like having over 900 pounds per square inch (PSI) pushing down on the watch's surface – a force that would crush most everyday objects instantly. Later, watches were even rated for more extreme depths like 1,220 meters (4,000 feet) – over 122 atmospheres of pressure, a truly crushing 1,790 PSI! These very high depth ratings proved the watches could handle the very specific and intense demands of COMEX's deep-sea operations.

                           

Impact on the Industry:

COMEX’s collaboration with Rolex helped push depth ratings from symbolic to scientific. Their real-world testing and demanding requirements laid the groundwork for ISO 6425, the international standard for dive watches, which formalized rigorous depth testing protocols and performance criteria. Depth ratings existed before COMEX, but COMEX was the turning point where those numbers started to mean something technically robust and verifiable.

The Helium Puzzle: Why Some Watches Have a Special Valve

Now, let's talk about something unique to saturation diving: the helium escape valve (HEV). This specialized valve is found exclusively on watches designed for the specific and extreme conditions encountered by saturation divers.

Here's why divers in these extreme environments breathe helium, and why it affects their watches:

Comabting Nitrogen Narcosis:

At the crushing pressures of deep water, the nitrogen in regular air (which makes up about 78% of what we breathe) becomes highly intoxicating, acting like a powerful anesthetic. This condition, known as "nitrogen narcosis," can severely impair a diver's judgment, coordination, and ability to think clearly – a potentially fatal condition at depth. Helium, unlike nitrogen, has very little narcotic effect at high pressures, allowing divers to remain alert and functional during their work.

Preventing Oxygen Toxicity:

While oxygen is essential for life, breathing it at very high partial pressures for extended periods can become toxic, leading to symptoms like muscle twitching, tunnel vision, seizures, and even death. In the deep, the percentage of oxygen in the breathing mix must be significantly reduced to stay safe. Helium helps dilute the oxygen, maintaining a safe concentration even at immense pressures.

Reducing the "Work of Breathing":

Gases become incredibly dense under high pressure. Imagine trying to breathe very thick syrup instead of air! Regular air would be too dense and exhausting to breathe at great depths. Helium is a much lighter and less dense gas than nitrogen or oxygen, making the breathing mixture significantly "thinner" and easier for divers to inhale and exhale, reducing fatigue during long, arduous dives.

This unique, helium-rich breathing gas is precisely why helium can eventually seep into watches.

Here's how it works:

• 1. Deep-Sea Living (Helium Ingression):

  When saturation divers live for days or weeks in their underwater saturation habitats, they breathe a special gas mix containing a high percentage of helium, all while being maintained at the same high pressure as the surrounding deep water. Helium atoms are incredibly, incredibly tiny—far smaller than even water molecules. Over time, while the diver (and their watch) is under extreme pressure, these minuscule helium atoms can actually infiltrate the watch case, bypassing the seals and gaskets. It's not a leak; it's molecular diffusion.

• 2. Coming Back Up (Decompression & Pressure Trap):

  When divers finish their mission, they cannot simply ascend to the surface. They must undergo a slow, controlled process called decompression, which can take days or even weeks. This gradual ascent allows the gases dissolved in their body tissues to safely leave their system, preventing a potentially fatal condition known to divers as "the bends." As the diver (and watch) comes up, the external pressure rapidly drops. However, the helium that has diffused inside the watch is now trapped and still at the higher pressure of the saturation habitat. If this internal pressure cannot equalize with the rapidly decreasing external pressure, that trapped pressure builds up. This internal pressure differential can become so immense that it can literally pop the watch's crystal (the glass front) right off with explosive force, akin to uncorking a champagne bottle with a tiny explosion!

• 3. The Helium Valve Solution:

  That's where the helium escape valve (HEV) comes in. This ingenious, tiny, one-way valve acts as a safety release mechanism. It allows the trapped helium inside the watch to escape safely and gradually as the diver ascends to the surface, preventing internal pressure buildup. It typically opens automatically when the internal pressure significantly exceeds the external pressure by a certain threshold, ensuring the watch remains intact.

Image Credit: Bob's Watches – "The Helium Escape Valve – What Is It, How Does It Work, And Do We Need One?" https://www.bobswatches.com/rolex-blog/resources/helium-release-valve-work-need-one.html?s rsltid=AfmBOorMoD4xQ3pXGugGxK5hOPHthUrNf-lTYSewllEkgD4XOZhNLEaf

Is it essential for you? For the vast majority of watch owners, including recreational divers, a helium escape valve is more of a cool "aspirational" feature than a real necessity. You would only ever truly need one if you were a professional saturation diver living in a deep-sea habitat for days on end. For typical scuba diving, even at moderate depths, decompression is quick enough that helium doesn't build up inside the watch to dangerous levels.

Why "Water Resistant," Not "Waterproof"? The Law Explained

You might be wondering, with all this talk of extreme depths and innovative seals, why don't watch companies just say their watches are "waterproof"? It's a great question with a definitive answer!

The simple reason is because of a law in the United States. Back in 1960, the Federal Trade Commission (FTC), the agency that protects consumers from deceptive advertising, stepped in. They determined that no watch could ever be truly "waterproof" under all possible conditions, indefinitely. Materials degrade over time, seals can fail, and unforeseen extreme conditions can push any limit beyond its design. To claim "waterproof" would be to make an absolute guarantee that no mechanical device could realistically uphold forever.

So, to avoid misleading consumers and setting unrealistic expectations, the law stated that watches cannot be called "waterproof." Instead, they must be called "water resistant," and they always come with a specific depth rating (like "Water Resistant 100m" or "Diver's 200m") to clearly inform consumers how much water pressure they can reliably handle under controlled testing conditions. It's about being transparent and honest with consumers about the capabilities and limitations of their timepiece.

                                                     

Your Watch, Your Adventure: Brigade Watches and the Subcommander

At Brigade Watches, we stand by the quality and reliability of our timepieces. Understanding the incredible history and engineering behind water resistance helps you choose the perfect watch for your everyday adventures and beyond.

For instance, our popular Subcommander model boasts a robust water resistance of 200 meters (or 660 feet). This rating is no accident; we designed the Subcommander to be a modern homage and reliable replica of the iconic Rolex Submariner, carrying forward its legacy of robust underwater performance for the everyday enthusiast.

As we discussed, 200 meters is equivalent to diving the entire length of two American football fields straight down, or going twice the depth of a typical large public swimming pool. This means your Subcommander can reliably handle pressures up to 20 atmospheres (or 20 bar), which is equivalent to approximately 290 pounds per square inch (PSI) pushing down on the watch's surface. To put this pressure into perspective, it's like having a stack of twenty fully-grown humans balanced on the face of your watch, or more vividly, enduring the crushing force of a commercial car tire inflated to over 15 times its normal pressure, applied directly to the watch crystal.

To put this in perspective for a human diver: a typical recreational scuba diver, breathing normal air, is typically limited to a maximum depth of around 40 meters (130 feet). Attempting to dive to 200 meters on standard air would be immediately fatal due to the crushing pressure, severe nitrogen narcosis (leading to disorientation and unconsciousness), and dangerously high levels of oxygen toxicity that would cause seizures and irreversible organ damage. Even highly specialized technical divers require complex mixed gases (like trimix, with helium to mitigate narcosis and precise oxygen levels to avoid toxicity) and extensive, multi-stage decompression procedures, often spanning hours or even days, to safely attempt dives of this magnitude. This highlights just how demanding the 200-meter threshold is for both human and machine, making your Subcommander a truly capable companion for your aquatic pursuits.

For the vast majority of people, diving to such extreme depths is entirely unnecessary and incredibly unlikely. After all, if the elite German military divers in WWII could accomplish critical and dangerous missions with their Panerai watches rated for 30-50 meters, you can be supremely confident that your Brigade Subcommander, with its robust 200-meter water resistance, is more than capable for any aquatic adventure you'll encounter in your daily life or recreational activities.

While the Subcommander isn't designed for the highly specialized world of extreme saturation diving (which would require a dedicated helium valve, as discussed!), its 200m water resistance provides truly robust protection and peace of mind for virtually all water-related activities you're likely to encounter. It's a testament to the century and a half of innovation we've explored, distilled into a reliable and stylish timepiece for your wrist.

Let us know what water-related activity you have done with our Subcommander Watch. Do you like the water resistance on it so far?