Any authorized watchmaker will be able to replace the battery of your timepiece. Do make sure the water resistance of your watch is tested after the replacement of the battery. It may be necessary to replace the gaskets of the caseback after opening the caseback in order to replace the battery.
The water resistance rating of our timepieces is based on pressure tests performed in our laboratories over a predefined period of time (usually 10 minutes). 100% of our watches are thus tested. The pressure conditions match those a unmoving swimmer or diver may be exposed to in a variety of water sports. Do note that the pressure increases with any intense movement. Pressure hoses etc. should never be directed at any watch as the pressure thus exerted might easily exceed the water resistance limit. In addition to the pressure tests our divers models are also water tested.
WATCH BATTERY, REPLACEMENT