Water Resistance Explained
Water resistance figures printed on the dial or caseback, such as 30m, 50m, or 100m, indicate the static pressure a watch has withstood during laboratory testing under the ISO 22810 standard, not a depth at which the watch can be safely used. The term “waterproof” has been formally removed from watchmaking standards, as no case retains a permanent seal: rubber gaskets at the crown, caseback, and crystal degrade progressively with use.
In practical terms, a 30m (3ATM) rating covers incidental exposure such as rain or splashes and is unsuitable for showering. A 50m (5ATM) rating permits brief contact, such as handwashing. A 100m (10ATM) rating is generally regarded as the minimum acceptable threshold for swimming. These figures are established under static conditions, whereas real-world activity (as diving into a pool or swimming strokes) can generate dynamic pressure well beyond the stated rating. This is why a 100m-rated watch remains unsuitable for scuba diving unless it additionally meets ISO 6425, the stricter standard governing dedicated diver's watches.
A Craft Mod watch holds up well through everyday moments
Because gaskets are subject to both age and heat exposure, periodic pressure testing is advisable for any watch regularly exposed to water. At Craft Mod, the water resistance rating of each build is stated directly on the product page, allowing the technical limits of the case to be understood clearly before use.