OCEAN AREAS WHERE DIVERS' BREATHING MIXTURES MIGHT BE REGENERATED BY GASEOUS EXCHANGE WITH SEA WATER.

To depths of 50 meters, a gaseous exchange process for regenerating breathing mixtures with sea water is almost universally feasible. At such depths the concentration of disolved oxygen is usually in excess of 4 milliliters per liter the energy for pumping sea water against ambient pressure is not excessive and scuba divers do not require helium-containing breathing mixtures. The concentrations of dissolved oxygen are adequate for regenerating breathing mixtures at all depths in the Arctic and Antarctic Oceans and at all but intermediate depths in the Atlantic Ocean. The Pacific and Indian Oceans are rather deficient in oxygen at all but very shallow depths. Development of an energy-conserving pump and a device for separating gas mixtures into their constituent gases will greatly extend the depths to which gas exchange processes for regenerating breathing mixtures with sea water are feasible. Such developments appear to be near at hand and they will render the gas exchange processes feasible even in areas of the ocean where the concentration of dissolved oxygen is merely a milliliter or two per liter. Author