Here in the age of Covid, people have realized that we should wash our hands a bit more often than we do on average, but that does bring with it a few problems. Our hands can dry out from all the soap and sanitizer, we will spend more time scrubbing, which could lead to irritation, and depending on how vigorously you wash, our watches could be splashed more than expected.
For rugged watches like a G-Shock or a diving watch this really isn’t a big deal, but for people wearing dress watches or the high-end ultra-complicated watches, this can actually pose a serious risk.
Possibly.
Some amount of water resistance is found in nearly all modern watches, a large percentage with 10 meters (30 feet) or more. But even for those with reasonable depth ratings of twenty to fifty meters, I say: That’s not good enough. I argue that, unless there is a practical reason to avoid it, all watches should have the water resistance of a dive-rated watch.
A dive-rated watch is usually considered a watch that can be used up to a depth of at least 300 meters (1,000 feet) – but a minimum of 100 meters (330 feet) is often good enough to go swimming and snorkeling. It might be thought that a watch that can withstand being submerged to a depth of 10 meters would be perfectly able to handle a little splashing while washing hands. But water pressure plays tricks with depth ratings.
Thanks to the incompressibility of water, a 10-meter depth rating can fail to prevent water finding it’s way into a case under the most mundane of circumstances, like being hit with a jet of water from your shower head. That 10-meter depth rating, which is the same as 1 ATM, or 33 ft, is tested in laboratory conditions while the watch is sitting perfectly still, and with fresh seals newly installed.
Don’t move
As soon as the watch moves around, water pushes harder against the rubber seals. If you add in temperature fluctuations (especially with hot water), this can cause the case and rubber seals to expand or contract in different amounts, possibly reducing the amount of force the seal can withstand. Depth ratings on watches sometimes come with restrictions that seem counterintuitive for this reason, like a watch with 100 meters of water resistance that you can shower with as long as it isn’t a hot shower.
If the watch is new and has fresh O-rings, it is possible that 10 meters of water resistance will do just fine in a hot shower, but effectiveness falls off with age. Even within a few months to a year of manufacture, there can be enough expansion and contraction from changes in temperature and humidity that will dry out the seals or cause the sealing surface to lose its ability to rebound. Essentially, rubber can get hard or even get squished and lose the ability to push against the case back or winding stem.
So why don’t dive watches deal with these issues? The short answer is that they do, but the design of the case and seals, and the choice of O-ring pliability (otherwise measured by Shore hardness) allows them more forgiveness because they are essentially overengineered to maintain that water-tight seal. How an O-ring is squished against the case when it is closed can vary, creating either two or four sealing surfaces per O-ring.
But more than that, the design of how the case closes affects how it seals against pressure. Super dive watches (those with over 1,000 meters of water resistance) make sure to design the components to flex into the seals under pressure instead of flexing in a way that creates a gap. Thicker and more durable O-rings can be used, or even flat rubber seals that provide greater surface area.
Getting inside
Setting aside chronographs, repeaters, and complicated watches with small correctors in the side of the case, this leaves the crown and crystal as leak points. I would argue that crowns and winding stems should all be the typical screw down version found on most diving watches. They are well established engineering solutions that protect the crown from being accidentally pulled (especially underwater) and protect the movement from being jarred since the screw down crown also isolates the movement when closed.
There are some design choices I have seen that literally prohibit the use of screw down crowns, namely Panerai, but that design is also specifically engineered to provide extra sealing force to the crown, an idea that could have a plethora of form factors for every type of watch. But for most other cases, a quality screw down crown with multiple O-rings would be best, such as the Rolex Twinlock and Triplock system which is arguably one of the best solutions out there.
One of the least concerning areas is the crystal and related gasket because it’s already been solved for most watches, at least those with standard, round crystals. Some odd-shaped crystals are still held in place not with a gasket but with adhesive, though with quality molding and the precise machining of sapphire crystals these days, even super accurate gaskets can be made for any shape. It’s important to consider crystal thickness but using something thick enough would only be a design issue for ultra-thin watches which represent a very small minority of the market.
Convincing the crowd
It's obvious that it would be feasible for nearly all watches, so why don’t most watches do it? The cost isn’t an issue, with a $100 G-Shocks and $200 Seikos hitting 100–300-meter water resistance all day. As with most products on the market, it’s a manufacturers perspective. Some brands clearly make sure their watches can handle anything, but most only think about the look, the market, and doing things the way they always have.
Seventy years ago, making every watch water resistant to at least 100 meters would have been impractical, and 300 meters of water resistance would have instantly boxed the model into a design corner. This isn’t true anymore, as materials and techniques have gotten better, patents expired, and the manufacturing costs for most watches have fallen to the point that using high-quality materials like stainless steel, titanium, ceramic, and sapphire isn’t relegated to ultra-high-end pieces.
You might make the argument that all those categories I mentioned previously such as chronographs, repeaters, and complicated watches with small correctors show that it’s not so simple, but I can point to dozens of watches that have solved these problems in a variety of clever ways. There are even watches that have more than a handful of extra complications and are still controlled solely via the crown, showcasing how good engineering can get around these issues to eliminate points of risk.
Making every watch capable of being used for swimming, snorkeling, or diving would not be a quantum leap, and it would provide much more protection for pieces that represent hundreds of hours of craftsmanship. It would ensure that no watchmaker would have to regularly repair water damage to a movement that could have easily been sealed safely away. Most importantly, it would allow people to go about their lives and not worry so much about their timepieces getting a little wet.
I’ve hoped for years that brands would start going this way, so my humble collection didn’t have to consist of capable pieces alongside watches I need to worry about. If I could strap any watch on my wrist and know that it could go anywhere and survive, this would make many more watches into capable everyday pieces. I imagine the average watch afficionado would say they’d prefer their watches completely protected from water, and given the cost and engineering requirements, I’d argue they deserve it.
