The definition of water resistance:
My new watch says it is water resistant, but what exactly does that mean? And how do I care for a water resistant watch? A watch marked as water resistant without a depth indication is designed to withstand accidental splashes of water only. You should not submerge such a watch in water at any time. Increasingly higher acceptable depths, normally indicated in meters, usually indicate higher levels of water resistance. There are a variety of different ways to make a watch water resistant. All such watches use "O" rings or rubber gaskets to seal the back of the case. A watch with a back that screws onto the case provides a higher degree of water tightness. Some crowns (the "winding stem") actually screw into the case, which increases water resistance even more.
General guideline for water resistant levels:
- - Water Resistant: Will resist moisture from accidental splashing, rain, sweat, etc.
- - Water Resistant 30M: Will resist moisture and can be submerged, no swimming.
- - Water Resistant 50M: Will resist moisture and can also be worn while swimming in shallow water.
- - Water Resistant 100M: Watch may be worn during snorkeling, skin-diving, and swimming.
- - Water Resistant 200M (or plus): Watch may be worn during standard scuba diving.
- - Water Resistant 1000M: Watch may be worn for deep sea diving.
Watch manufacturers use other terms to measure water resistance:
- - A.T.M. (atmosphere), where 1 A.T.M. equals 10 metres.
- - Bar, where 1 bar equals 10 metres.
Water resistant chart: