Hi Robert,
I’m not sure if I understand your question well??!!
Nobody should plan a dive with the intention to experience a narcosis!
A nitrogen narcosis is generally described as being euphorically intoxicated.
Typically divers can become aware of its effects at about 30m depth.
But it is hard to predict what reactions a diver may encounter as it varies with each person and with each dive (depending on depth, personality, mood, dive fitness, anxiety, cold, etc.). The effects can be restricted reaction, faulty reasoning, calculation errors, overconfidence, euphoria, but also aggressivity, anxiety or panic.
For this risk it’s not recommended to use normal air for dives deeper than 30m.
An oxygen intoxication can occur, if the oxygen exposure exceeds a partial pressure of 1.6 atmospheres. This is why nitrox dives are limited to certain depths. The symptoms range from vertigo, nausea, vomiting, vision and hearing difficulties to muscle twitching, spasm, convulsions and fainting, which underwater usually results in drowning.
To prevent oxygen toxicity during deep dives, special gas mixtures and special training are required.
As the symptoms of a nitrogen narcosis will disappear when the diver ascends to shallow depth (in case he is still able to do so), the oxygen intoxication might be irrevesible.
Take this in consideration when you plan your dives!
Barakuda
Getting drunk on air instead of booze. 
Linear Mode
