The water resistance of CASIO watches is standard-compliant as per DIN 8310/ISO 22810. These standards describe the various classes of water resistance and the test method used to determine water resistance. Models that do not have the "Water Resist" label are the exceptions in this regard. These watches must never come into contact with water.

In principle, water resistance according to DIN 8310 and ISO 22810 is not a permanent characteristic, since existing seals naturally wear with age. Extremely high and low temperatures, solvents and cosmetics accelerate this process, whereby seals quickly become brittle and porous and the water resistance of the models is no longer guaranteed. Watches should be used in "normal" temperature ranges, between approximately + 10°C to + 50°C.

Scope:
These standards apply to the general wristwatch usage.
Watches with metre indications for water resistance cannot be used immediately in this water depth, however, as water resistance metre indications are merely a pictorial representation of the test pressure.
A wristwatch resists the influence of water at the static pressure indicated on the watch (e.g. 10BAR) and theoretical immersion in water at the indicated depth. Movements in the water, such as a violent swimming motion or a blow to the water, can result in a dynamic pressure that exceeds the specified static pressure many times over and thus impairs the specified water resistance.