How to tell someone it's break time in a high noise environment (idea)

Scuba divers often use the following, one after the other:
-Tap the wrist in the area of the watch.
-Cock the wrist backwards in a pantomime of chugging a beer.
The resulting meaning: Its miller time.
This is, obviously, not a high-noise environment, but rather its opposite. Same principle, tho. :-)