Why watches aren’t waterproof!
The International Organization for Standardization issued a standard (ISO 2281) that mean watches can’t be described as “waterproof”, this even applies to deep-sea diving watches although there is another standard (ISO 6425) for divers watches, so your only “water resistant” watch is not sub-standard! All watches will fail under certain conditions, so none are totally waterproof!
The divers watch standard ISO 6425 is a very much more complicated and rigorous set of tests compared to that of jewelry watches, as would be expected considering a diver’s life could depend on accurately knowing the time. There are tests about readability in adverse conditions, magnetic interference tests, extra temperature and condensation tests to name but a few.
Water resistant figures basically refer to the watches ability to keep out still water at a given pressure under test conditions, temperature is also a factor and tests are also made regarding condensation.
So when a watch is said to be “water resistant” to 100m, it simply means it can resist water pressure equivalent to that found under a 100m column of water, not that it could be worn safely to this depth for diving.
This is because if the watch and water undergo relative movement the pressure can increase e.g. a watch worn by a surface swimmer might only get submerged up to a metre, but the pressure exerted on the watch when the arm quickly enters or moves through the water will increase it further and entering the water off a springboard may create the equivalent pressure that would be encountered under many metres of water pressure in stationary conditions.
Thus the “water resistant” figure is not an absolute depth guide that the watch can be worn to, but more of a guide of what activities the watch wearer can safely do whilst wearing it. Getting a watch wet whilst cleaning out the home aquarium does not exert the same water pressure on the watch as falling off a jetski at 40 m.p.h., it is not the depth that’s important, just the pressure!
Watches have seals to help keep out water, these are made out of various materials that can be affected by chemicals (including sea water) or temperature, so wearing a watch in a steam room or hot tub may also compromise the water resistance of your watch.
So whatever type of watch you buy, whether it’s divers watch,dive watch,sport watch or fashion watch, understanding the figures below will help you protect your watch against water damage.
A General Guide to Activities “Water Resistant” Watch Figures Can Be Used For
30m (99ft) Accidental splashes.
Not Suitable for Diving, Fishing, Snorkelling, Swimming.
50m (166ft) Fishing.
Not suitable for Snorkelling, Swimming, Diving.
100m (330ft) Snorkelling, Swimming, Sailing, Surfing.
Not suitable for Diving.
200m (660ft) Professional Marine work, Active Water Sports.
Not suitable for Diving.
1000m (3300ft) Scuba Diving.