WATER RESISTANCE MARKINGS

Water resistance markings are among the most frequently misunderstood indicators on a watch. They appear on the case back, dial, or both, and are expressed in several different formats including meters (e.g., "100M"), BAR (e.g., "10 BAR"), ATM (atmospheres), or simply as "WR" or "WATER RESISTANT." One of the most common misconceptions is that a "50M" rating means the watch is safe for swimming at depths up to 50 meters. In reality, these ratings are determined under static laboratory conditions and do not account for the dynamic pressure created by arm movements, water jets, or diving. The ISO 22810 standard governs how watches earn their water resistance rating, while the more stringent ISO 6425 applies specifically to dive watches and requires every individual watch to be tested. A watch marked "30M" or "3 BAR" is generally only splash-proof, suitable for hand washing but not submersion. Ratings of "100M" or "10 BAR" are typically considered safe for recreational swimming and snorkeling, while "200M" or above is recommended for actual diving. It is also important to understand that water resistance degrades over time as gaskets age, lubricants dry out, and the case sustains minor impacts. Manufacturers recommend having the water resistance tested annually, especially before any planned water exposure. A watch that was rated "200M" when new may no longer meet that standard after years without service, so these markings represent the original specification rather than a permanent guarantee.

Water Resistance

WR 50M / 5 Bar Marking

A water resistance rating of 50 meters (5 bar/ATM), indicating the watch can handle everyday moisture like rain and hand washing. This rating is not suitable for swimming or submersion.

Water Resistance

WR 100M / 10 Bar Marking

A water resistance rating of 100 meters (10 bar/ATM), generally considered suitable for swimming and recreational water activities. Not rated for scuba diving or high-impact water sports.

Water Resistance

WR 200M / 20 Bar Marking

A water resistance rating of 200 meters (20 bar/ATM), suitable for serious water sports and recreational scuba diving. This is the standard entry-level rating for purpose-built dive watches.

Water Resistance

Bar / ATM Pressure Rating

A water resistance rating expressed in bar or ATM (atmospheres) instead of meters. One bar/ATM approximately equals 10 meters of water depth in testing pressure.