[edwardsdl]

Narcosis is nothing to trifle with. After a particularly bad experience at 150ft on air, I understand why some agencies advocate for a maximum equivalent narcotic depth* of 100ft.

*For the non-divers out there, it’s possible substitute a less narcotic gas - typically helium but not always - for a portion of the narcotic gas in a mixture. Equivalent narcotic depth (END) is a way to equate a mixture’s narcotic effect to that of air at a given depth.

[nradov]

Military and commercial divers have done some experiments with hydrogen to reduce narcosis without using helium. But the fire risk makes it way too dangerous for civilian sport diving.

Neon might also reduce narcosis but it's more expensive and the work of breathing is higher.

[rob74]

** 150 ft ~= 45 m; 100 ft ~= 30 m (for the other non-Imperials out here ;) )

[diveanon]

Once you start getting to technical depths you operate under the assumption that you are alone, even when diving with a buddy.

I know some french federation divers who will tape their hands to their hand power inflator to avoid confusion when experience narcosis at depth.

At first I thought it was a goofy idea, but after experiencing debilitating narcosis at 60m I had second thoughts about it.

[nradov]

No you really don't. I do a lot of technical diving and depend on my buddies for safety. The key is to select reliable buddies who have been properly trained.

And taping your hand to your power inflator is just too stupid for words. Put some helium in the mix.