Water resistance is one of the most misunderstood watch specifications. The number on the dial or case back is a pressure rating tested in a laboratory, not the depth you can actually dive to. Here is what each rating means in everyday life.
What the ratings mean
- Water resistant / 30 m (3 ATM): handles splashes, rain and hand washing. Not for swimming or showering.
- 50 m (5 ATM): fine for brief contact with water, such as light swimming in a pool. Avoid diving or water sports.
- 100 m (10 ATM): suitable for swimming and snorkelling.
- 200 m (20 ATM) and above: designed for swimming and recreational diving. Watches marked “Diver’s” are built to a dedicated diving standard (ISO 6425).
Why a 30 m watch can still get wet inside
Moving your arm through water, jumping into a pool or the force of a shower can create pressure spikes higher than the static test. Hot water and steam also make the seals expand and soften. That is why we recommend at least 100 m for regular swimming.
Simple rules to protect your watch
- Screw the crown down fully if your watch has a screw-down crown, and never pull out the crown or press chronograph pushers underwater.
- Avoid hot showers, saunas and steam rooms – even with diver’s watches.
- Rinse with fresh water after swimming in the sea or a chlorinated pool, then dry with a soft cloth.
- Leather straps and water don’t mix – swap to a rubber, fabric or steel strap for swimming.
- Seals age over time. Have water resistance checked regularly (for example every year or two, and whenever the case back is opened, such as for a battery change).
Seeing fog under the glass?
Condensation or droplets under the crystal mean moisture has got in. Stop wearing the watch and have it checked by a professional as soon as possible to avoid rust and damage to the movement.
Not sure what your watch can handle? Send us the model on WhatsApp and we will tell you.