Watch WinderCare
Water resistance, explained
A depth on the dial is a laboratory pressure rating, not a promise about how deep you can dive. And it only holds while the gaskets are healthy, so it quietly fades with age.
What the ratings mean
| Marked | In practice |
|---|---|
| No marking | Keep it dry. Wipe off rain and wash your hands with care. |
| 30m / 3 bar | Splashes, rain and hand washing. Not showering or swimming. |
| 50m / 5 bar | Brief, gentle swimming at a push. Better kept out of the pool. |
| 100m / 10 bar | Swimming and snorkelling. |
| 200m / 20 bar and up | Swimming, snorkelling and recreational diving. |
| "Diver's" (ISO 6425) | Built and tested for diving, with a unidirectional bezel and legible dial. |
The numbers look generous because the test is static: the watch sits still in a pressure chamber. Moving your arm through water, diving in, or a jet of water all add pressure the test doesn't cover.
Gaskets wear out
Rubber seals in the caseback, crystal, crown and any pushers keep water out. They dry, harden and crack over time, and heat and chemicals speed that up. A ten-year-old 200m watch that has never had its seals replaced may not survive a swim. If you take a watch in water, have it pressure-tested every year or two. Many watchmakers do it while you wait, and it's cheap compared to a flooded movement.
Habits that keep water out
- Screw the crown down before it gets wet, every time. Check it after winding or setting the time.
- Never use the crown or pushers underwater, unless the chronograph is specifically rated for it.
- Rinse in fresh water after the sea or a chlorinated pool, with the crown screwed down, then dry it.
- Skip hot showers, saunas and hot tubs. Heat makes the seals expand and contract, and steam gets through gaps that water can't.
- Keep soap, sunscreen and perfume off it. They break down the gaskets.
If water gets in
Fog under the crystal that doesn't clear, or droplets on the dial, means the case has let water in. Don't wait for it to dry by itself: take it to a watchmaker within a day or two. Moisture rusts steel parts in the movement quickly, and a quick opening and drying costs far less than replacing them.