A watch is not water resistant unless stated. Most water resistant watches are not designed for prolonged active use in water.
Water resistance is stated as a depth, this means that it has been tested in a laboratory to withstand a static pressure for a short period only at the stated depth.What is ATM?
Pressure tests are measured in ATMs. ATM stands for Atmospheres and is used for ratings for water resistance. Each ATM is equivalent to 10 metres.
0ATM - Not guaranteed to be water resistant, care must be taken and watch should be removed before washing hands.
3ATM - Splashproof. These watches can be worn whilst washing hands, in the rain etc but should not be immersed in water.
5ATM - Can withstand splashes and can be immersed into water for short periods. Not recommended for fishing or water sports.
10ATM - Can be used for swimming.
20/30ATM - Can be used for diving, snorkelling and high impact water sports.
Watches should be tested for water resistance yearly and gaskets replaced where necessary to maintain water resistance.
Certain chemicals in water can damage the watch seal as well as perfumes, aerosol sprays and other cosmetics.
Never pull out the crown whilst using the watch in and around water. If the watch has a screw down crown you must ensure it is firmly shut before immersing in water.