Can I shower with a 30m water resistant watch?

No. A 30m (3 ATM) rating is only splash-proof. Hot shower water, soap, and changing water pressure can all push water past the gaskets. Manufacturer guidelines and the ISO 22810 standard specifically exclude showering for 30m-rated watches.

What does 100m water resistance actually mean?

100m (10 ATM) means the watch passed a static pressure test equivalent to 100 metres of still water. In real-world use with motion and temperature changes, this translates to safe surface swimming and snorkeling — but not scuba diving. For diving, you need a dedicated dive watch rated to ISO 6425 (typically 200m+ with additional tests).

What is the difference between ATM, bar, and meters?

They are almost equivalent. 1 ATM = 1 bar ≈ 10 metres of water depth. So 3 ATM = 30m, 5 ATM = 50m, 10 ATM = 100m, and 20 ATM = 200m. These are static lab pressures — real-world dynamic use (swimming strokes, impact, warm showers) exposes a watch to pressures beyond its rating, which is why the real-world guidance is always more conservative than the printed number.

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Water Resistance Checker

Last updated: April 2026 · 4 min read

Enter your watch's water resistance rating below. The tool shows exactly which activities are safe, which are risky, and which will almost certainly damage the watch.

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Why the real-world guidance is stricter than the number

Water resistance is measured statically — a watch is pressurised in still water and tested for leaks. Real-world use is dynamic. Swimming strokes create pressure spikes, hot showers cause gasket expansion and contraction, and temperature shocks degrade seals over time. This is why a 100m watch isn't rated for scuba diving, and why even 30m-rated watches shouldn't go near a shower.

Gaskets also age. Most watchmakers recommend a pressure test and gasket service every 2 to 3 years for any watch regularly exposed to water. A watch with a printed 200m rating but 8-year-old gaskets may leak at 20m.

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