What Does Watch Water Resistance Mean? 3, 5 and 10 ATM Explained
Ratings such as 3, 5 or 10 ATM show the pressure a watch withstood under laboratory conditions. They are not real diving depths. A watch marked 30 metres is not designed for a 30-metre dive.
What the ratings mean
As a general guide, 3 ATM suits everyday splashes, 5 ATM can handle light surface use, 10 ATM is better for swimming, and 20 ATM and above is aimed at water sports. Check your watch's manual for exact limits.
Is water resistance permanent?
No. Gaskets harden and wear over time, and knocks can affect the seal. Never assume a pre-owned watch still meets its original rating.
What to watch for
If the crown screws down, make sure it is closed before water contact. Do not press the crown or pushers underwater. Hot showers, saunas and sudden temperature changes can also strain gaskets. Rinse with fresh water after salt water.
Our service team carries out water-resistance testing. If you see condensation under the crystal, stop wearing the watch and have it checked.
Frequently asked questions
Can I swim with a 30-metre watch?
It is generally not recommended. 30 metres, or 3 ATM, suits everyday splashes.
How often should water resistance be tested?
A yearly check is a common recommendation. Test sooner if you use the watch in water often or it has taken a knock.