Air of course is a suitable breathing mixture for a diver based primarily on nitrogen as the oxygen diluent.Air is in fact the preferred breathing mixture for all dives to depths of less than about 150-200 fsw (feet of sea water). read more
Best Answer: The helium decreases oxygen density in the lungs under pressure. When you dive beyond 160 foot depth for any length of time, the oxygen molecules cannot saturate lung tissue. The helium helps with the delivery of the oxygen to the lungs at deep pressure dives. read more