In Reply to: Kinetics and narcosis? posted by physics on July 05, 2006 at 21:21:59:

Personal experience says narcosis comes on quickly at depth and reaches stasis inside a few minutes unless other factors like exertion or accelerated breathing exacerbates the problem.

This timing is supported by the literature. Full resperatory cycle time is something like a minute or two.

Does a free diver who dives to 150 and ascends immediately feel narced? I don't know. The host of free divers who regularly exceed 100 feet is pretty small. A lot smaller when you're talking about 150 feet.