Nitrogen Narcosis Nitrogen narcosis or inert gas narcosis is a reversible alteration in consciousness producing a state similar to alcohol intoxication in SCUBA divers at any depth, but commonly beyond 30m. Jacques Cousteau famously described it as the "rapture of the deep". Its precise mechanism is not well understood, but it appears to be a direct effect of high nitrogen pressure on nerve transmission. The onset is hard to recognize, its severity is unpredictable, and it can kill, from its own toxic effect or due to the resulting illogical behaviour. However the cure for nitrogen narcosis is a simple one, as effects disappear upon ascending to shallower waters. source: http://en.wikipedia.org/wiki/Nitrogen_narcosis

Nitrogen (N2) An colorless, odorless, tasteless gas which makes up 79% of the air. Nitrogen is a gas at room temperature and becomes a liquid at about 77 K, -196

Nitrox Nitrox is any combination of Nitrogen, N2 and Oxygen, O2. See Enriched Air Nitrox, (EAN).

Normoxia The normal breathing of air with its oxygen PO2 at .21 ATA, sustains life. One can become unconscious at breathing levels of PO2 of .1 ATA. See Hypoxia.