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.
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.
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.
*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.