Select your watch’s water resistance rating and instantly see which activities are safe. Clear, practical guide for 30m, 50m, 100m, 200m, 300m and professional dive ratings.
Water resistance ratings are tested in static laboratory conditions. They do not mean you can dive to that depth in real life. Movement, water pressure changes, temperature and age of gaskets all reduce the real-world protection.
| Rating | Realistic Use |
|---|---|
| 30m / 3 ATM | Splash resistant only |
| 50m / 5 ATM | Rain, hand washing, light splashes |
| 100m / 10 ATM | Swimming, snorkeling (surface) |
| 200m / 20 ATM | Recreational swimming & snorkeling |
| 300m+ | Serious diving (with proper dive watch standards) |
• Never operate the crown or pushers underwater unless the watch is specifically designed for it.
• Screw-down crowns must be fully tightened before any water exposure.
• Gaskets age — a 10-year-old “100m” watch may no longer be safe for swimming.
• Hot showers and saunas are harder on seals than cold water because heat expands materials and steam can enter.
• After any service, water resistance should be re-tested.
30m → Avoid water as much as possible. Hand washing only if careful.
50m → Rain and splashes are fine. No swimming.
100m → Swimming and surface snorkeling are usually OK. No deep diving or high-impact water sports.
200m → Good for regular swimming and snorkeling. Still not a substitute for a proper dive watch if you free-dive deep.
300m+ ISO → Suitable for scuba and professional diving when the watch meets full dive-watch standards.
Can I shower with a 100m watch? Many people do, but it is not recommended as a daily habit. Soap, shampoo and hot water can degrade gaskets over time. If you must, make sure the crown is fully screwed down.
What does 10 ATM mean? 10 ATM (or 10 bar) is the same as 100 metres water resistance. It is a pressure rating, not a guaranteed diving depth.
Is a 200m watch a dive watch? Not necessarily. A true dive watch should meet ISO 6425 standards (luminous markers, unidirectional bezel, specific testing, etc.). Many 200m fashion watches are only suitable for swimming.
Why do manufacturers give such high metre ratings? The laboratory test is static. To survive real movement in water, manufacturers use higher pressure ratings so the watch remains safe during normal swimming and sport use.
How often should water resistance be tested? Ideally once a year, or after any battery change, crown work, or crystal replacement. Many watchmakers can perform a pressure test in a few minutes.
Can I go in the sea with a 100m watch? Yes for surface swimming and snorkeling, provided the seals are in good condition and the crown is secured. Rinse with fresh water afterwards.