Does the helium valve excite you Well, its useful for commercial divers only that too, only them doing very deep saturation diving. You need to live underwater for that, in habitats filled with a mixture of breathing gases, one of which is helium. The helium molecules are small enough to pass through the waterhumidity protection of the watch and expand as it surfaces due to dropping pressure. This damages the watch. The valve, when opened, lets the helium escape.