The waterproofness of a watch, what is it?
What is the water resistance of a watch?
The waterproofness of a watch corresponds to its resistance to water.Indeed, underwater, a watch is subjected to an atmospheric pressure different from that on the surface.
This pressure is expressed in atmosphere (ATM), in the open air the pressure exerted is 1 ATM.
Its watertightness therefore corresponds to its resistance to the water pressure that it can withstand.
The different types of seals:
- 3 ATM: This is the minimum pressure, the watch resists simple contact with water like resistance to rain.
- 5 ATM: The watch can be dipped under water but without depth such as washing hands, showering or taking a bath.
- 10 ATM: The watch is resistant to a small depth, so it can be used for swimming or bathing. (100 meters max)
- 20 ATM: The watch is depth resistant, it can be worn for shallow diving. (200 meters max)
- 30 ATM: The watch is specialized, it can be used for scuba diving. (300 meters max)
More technically, a pressure of 5 ATM corresponds to the pressure of a column of water of 50 meters on a surface of one square centimeter.
Our advices :
The water resistance of a watch varies over time and according to its use, so it is important to have it checked by a watchmaker on a regular basis.
NB: Washing the watch in fresh water after exposing it to sea water prolongs its life.
Where is the water resistance of a watch indicated?
The water resistance of a watch, expressed in (Bar/ATM/Meter/Foot) is systematically indicated either on the dial or on the back of the case depending on the model.