Comment by belorn

I am not jsjohnst, but the only additional nitpick is that Heliox is any blend that is exclusively helium and oxygen and the reason why heliox is more commonly used for deep dive is that helium has less resistance compared to nitrogen, meaning that pushing compressed air through ones respiratory system takes a bit less effort. Helium in heliox is thus used to displace the nitrogen, with the oxygen ratio being adjusted based on health, depth, bottom depth, purpose, decompression, surface interval and so on.