Here is a tip for you.
If you happen to wash your watch, cell phone, blackberry, or any other small electronic - try this.
Removed the battery from the device (and chip if it is a cellphone).
Place the device in a baggie full of dried white rice.
Leave it there for three days.
The rice tends to soak up all of the moisture.
It also helps prevent later oxidation, which may be why the OP's watch stopped a couple of weeks later.