I want one:
Alan Izhar-Bodner, an Israeli inventor, has developed a way for divers to breathe underwater without cumbersome oxygen tanks. His apparatus makes use of the air that is dissolved in water, just like fish do.
The system uses the “Henry Law” which states that the amount of gas that can be dissolved in a liquid is proportional to the pressure on the liquid. Raise the pressure – more gas can be dissolved in the liquid. Decrease the pressure – gas dissolved in the liquid releases the gas.
Via Live Science.