The water resistance of your watch is assured by an ensemble of gaskets. The gaskets are under constant strain and wear naturally. Having the water resistance of your watch checked on a regular basis allows us to determine if it is still satisfactory. If it is not, the water resistance gaskets will be replaced. Under normal wearing conditions, it is recommended that you have the water-resistance gaskets changed every two years, when you have the battery changed for example, to guarantee optimum safety. It is particularly recommended to have these gaskets checked regularly (every year) if the watch is worn while playing sports or if it frequently comes into contact with water. Finally, if your water-resistant Cartier watch shows condensation under the glass, we recommend that you take it to a Cartier boutique , authorized dealers or approved After-Sales Service centre as soon as possible so that the issue can be corrected.