From zeno-watches,
The water resistance is only guaranteed if the watch is declare on the dial and the watch has not been subjected to severe shocks, the crystal or crown are not damaged, the recommended service and checkings been done, and the instructions for changing the battery have been carefully followed.
WATER RESIST (water protectet) *=
These watches are protected against water drops (the watch has to be protected against water!)
WATERRESISTANT 30M (3ATM) *=
These watches can be used for car washing, bathing, shower, moutain climbing, parachuting, hang gliding, or skiing - it is resistant againtst perspiration, water vapour, rain drops.
WATERRESISTANT 50 M (5ATM) *=
These watches can be used for swimming, car washing, bathing, shower, moutain climbing, parachuting, hang gliding, skiing - it is resistant againtst perspiration, water vapour...
WATERRESISTANT 100 M (10ATM) =
These watches can be used for watersport, snocheling, swimming, car washing, bathing, shower, moutain climbing, parachuting, hang gliding, skiing - it is resistant againtst perspiration...
WATERRESISTANT 200 M (20ATM) =
These watches can be used for diving (without equipment), watersport, snocheling, swimming, car washing, bathing, shower, moutain climbing, parachuting, hang gliding, skiing - it is resistant againtst perspiration, water vapour, rain drops.