Gas narcosis in scuba diving Narcosis in scuba diving is the change in thinking and awareness, sensory and motor function and behaviour that occurs at depth.  Breathing gas at depth leads to narcosis, often noticed around 30m it can be an issue from around 20m and below. What does nitrogen narcosis mean? Narcosis: “a state of stupor, drowsiness, or unconsciousness produced by drugs.” Oxford English Dictionary Narcosis is … Continue reading What does nitrogen narcosis mean?