Most watches these days are made with some sort of protection against water damage, even watches that aren’t designed to get wet. For example, watches which are dust-resistant are also likely to give a great amount of protection from water or moisture. With the popularity of dive watches, watch waterproofing has advanced considerably.

What Is the Difference Between Waterproof and Water-Resistant?
No watch is actually fully waterproof because the ability of a watch to keep out water depends on the pressure placed on it by the water, and for this reason, most watches are labeled “water-resistant” rather than “waterproof.”
Watches are designed with seals to make them as waterproof as possible, and in many cases, the tightness and impermeability of the seals increase the deeper you go underwater. However, the huge pressures that are found at lower depths, even at 40 or 50 meters, are enough to cause most watches to let water in.
Many aquatic watches designed for swimming and diving have specially designed crowns and bezels to prevent any water from getting inside. Some of the more expensive ones, like Rolexes, have a secondary backup seal, so that even if the first is penetrated, moisture cannot pass into the watch mechanisms. If you have a waterproof watch, it’s always prudent to make sure the crown is fully pushed in before diving in.
Some watches will be able to cope with a quick splash when you wash your hands, others can be used in the shower safely, while other models can be fully submerged in the sea or a pool. Most watches labeled waterproof are dive watches, which can go down to hundreds of meters without allowing water ingress.
How Do I Know What My Watch Is Capable Of?
Before you purchase your watch, you should look on the manufacturer’s site and see what specifications it has in regard to water resistance. Watches that are deemed to be water-resistant will have been stamped as such, and there may even be a figure on the watch showing how it performs on a static pressure test. This may be noted in the actual unit of pressure, which is known as an atmosphere (ATM) or bar. Some watches will even have a meter rating, or it could be in feet.
Seems pretty straightforward, right? The watch says it can go down to 50 meters and still not leak, so you should in theory be able to dive to that depth and not experience any issues. That is actually wrong, we’ll explain why.
A depth rating is calculated in a short test of pressure at the depth it has been marked with. It does not, however, consider the fact you might be swimming with it for an hour or more, constantly submerged. It doesn’t acknowledge the fact that you might be sitting with it in a hot tub or warm bath for a long period, which could affect its functioning.
A non-moving static testing environment doesn’t reflect the reality of your wrist cutting through the water every few seconds, the sudden change in pressure when you dive from a height into the pool below, or when you knock it on the pool wall accidentally. All of this affects the lifespan and water resistance values of your watch.
So why do they put this rating on watches in the first place? Depth ratings offer a level of standardization that allows buyers to compare different watches accurately. Some dive watches will have much larger depths of up to 300, 400, or 500 meters, and these will have been tested at those depths in the same way. So, while a depth rating based on a pressure test is not perfect, it is a very good indication of what your watch can withstand.
What Are Waterproofing IP Codes?
IP Codes (IP stands for ingress protection) were created as a measure of standardization by the IEC (International Electrotechnical Commission). They are more complicated than the standard static depth pressure tests performed on watches, and multiple tests are involved to give the watch a single rating. An IP rating covers everything from how well the casing protects from dust to water ingress and other types of pressure contact.
If your watch has a rating of IP X with a number after it, it is letting you know how it performs against water and moisture. For example, a rating of IPX6 means that it has been able to withstand a strong jet of water sprayed at it. Sometimes you will see multiple codes, such as IPX3 or IPX5, on a single watch, and this means they have been thoroughly tested in a range of water conditions.
The first letter (X in our example) stands for protection against foreign objects such as dust. For most waterproof watches, this should be 6 (dust-tight) and waterproof smartwatches will usually have an X instead.
The second letter ranges from 0 to 9 as follows:
- Protection from droplets falling vertically on it (1)
- Protection from droplets falling on it at up to 15 degrees (2)
- Water sprayed on it at an angle of 60 degrees (3)
- The case sprayed with water in all directions for at least 10 minutes (4)
- Protection from water jets in any angle (5)
- Complete protection from low and high-powered jet sprays (6)
- Temporary immersion in water (7)
- Full watch immersion for half an hour (8)
- Able to cope with jet sprays of high temperatures and steam-cleaning (9)
The full list of IP ratings can be found on the IEC website here for both solid and liquid.
A Guide to Watch Waterproofing ISO Ratings
The classic and perhaps best-known rating for watch water resistance is the ISO rating, which stands for the International Organization for Standardization. To be given an ISO rating, multiple tests are conducted on a timepiece to see how it fares under different circumstances. A watch that passes can legitimately be given the ISO seal of approval.
ISO rating tests cover everything from basic water resistance to how watches react to condensation and temperature changes.
The most basic test, known as the ISO 22810, was developed in the early 90s but received a revamp 20 years later to bring it in line with modern standards. This is used to test the vast majority of watches and their water resistance, and they can be separated out as follows from the testing:
30 meters / 3 BAR – only has a resistance to splashes such as rain or from washing your hands. It is not recommended to take this watch in the shower.
50 meters / 5 BAR – a rating for everyday watch use. You can shower or do light swimming with this watch on and not have any problems, but do not use it for diving and snorkeling.
100 meters /10 BAR – this rating indicates the watch can be submerged underwater for long periods of time. This is ideal for use when swimming or showering.
200 meters / 20 BAR – the highest rating a watch can get from the ISO without being a dive watch. You can use this watch for water sports or snorkeling for any length of time.
After this level come the diving watches. Watches that receive an ISO 6425 rating may be labeled divers’ watches. To meet this standard, watches are tested specifically for how they cope under pressure, shock, and full immersion. Testing starts at depths of 100 meters and continues to a depth of 500 meters, which only a handful of watches in the world can cope with.
Watches of this standard can withstand 300 meters / 30 BAR and higher. As these are used for deep diving, they have a special escape valve for helium, and the dial is likely to be branded with the words ‘for mixed-gas diving.’
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Last Updated on February 28, 2022
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