How do submarines get air?
Submarines make air from water. H2O. First we make fresh water from salt water by means of Evaporation, we heat up the salt water the steam that comes off is fresh water, we cool the steam and we have fresh water. The remaining salt/brine is pumped overboard. We send the fresh water to an electrolyser. The electrolyser shoots a massive shot of electricity through the water and splits it in two, H2O,, Hyrogen goes one side, oxygen the other. It is obviously more complicated than this , try searching electrolosis on the world wide web.
