Canasia Sports

Can I sidetrack you onto giving me an opinion on the posting that pointed to helium being 23% as narcotic as nitrogen rather than the zero we blithly assume and the effects on equivalent narcotic depths? I didn't see any posting that stated that (I don't read every post on UKRS - only ones with interesting subjects - sometimes) Do you really mean Helium and not Oxygen? I haven't read anything about Helium being narcotic at all. I have read a lot about Oxygen being narcotic. Personally, I don't see any effect. That Oxygen is as narcotic as Nitrogen (or slightly more) seems to be widely accepted but the figure of 23% as narcotic for Helium struck me as interesting. Firstly from the point of 23% being a rather *accurate* number for something as nebulous as narcosis and secondly from the point of view of do these efects just add up like partial pressures? Somehow the idea that at 48m on air I'm narked out of my skull does not seem to imply that at 19m I am 50% deskulled. This stuff just ain't linear so surely the components won't just add. nigelH