A Comprehensive Guide of the Watch Water Resistant
Watch water resistance chart:
Note: Every 10 meters depth will increase the pressure by 1 atm. The watch will easily burst when the pressure of the watch inside and outside is different, therefore watch manufacturers commonly use the pressure value to test the water resistant, BAR or ATM are used to indicate the available water resistance depth.
3atm or 30 meters water resistant:
It means that it is suitable for daily use. It cannot be used for swimming or immersed in water as it can only resist a small amount of hands and face splashing water and rain.
5atm or 50 meters water resistant
It means that you can wear the watch for swimming in shallows but not for diving or snorkeling.
10atm or 100 meters water resistant
Simply 10 atm water resistant watch is safe for swimming, but not diving. Your arms are always swiping when swimming, so it is different from static water pressure.
20atm or 200 meters water resistant
It means that you can wear the watch for diving and scuba diving; it conforms to the ISO international standard.
Watch Manufacturer Suggests:
If you plan on swimming with your watch, have it water tested once a year. This helps keep an eye on the gaskets and keeping a constant seal. Never operate chronograph movements underwater unless your watch specifically states that it can be used. Do not allow sudden and rapid air pressure changes.