The Rolex Submariner is waterproof to a depth of 300 meters, thanks to the company's Triplelock winding mechanism that keeps the oyster case of the watch watertight. If your Submariner has stopped working, it likely it needs to be wound. If you find that the watch doesn't start after following the steps below, you'll need to contact your dealer. Opening a Rolex watch and trying to repair a problem yourself could invalidate your warranty.
Take the watch off of your wrist.
Unscrew and release the Triplelock crown mechanism and wind the watch. Rotate the crown between 30 and 40 times. Don't worry about over-winding your Submariner, as all Rolex watches are equipped with a built-in protection mechanism.
Screw the locking mechanism back into place and put the watch back on your wrist. If it has not started, rotate your wrist gently to "kick-start" the rotor. If it still doesn't start, take it off your wrist, put it to one side and allow it to start on its own without further interference.