Serious question, did anyone else not know mixed-gas diving had a specific depth cutoff for helium?

I read on the Divers Alert Network site last night that once you go past 130 feet, helium is pretty much standard in the mix because nitrogen narcosis hits way harder than I thought, so now I'm rethinking my whole training plan for deeper wrecks.

2 comments

2 Comments

kelly.dylan1mo agoMost Upvoted

HOLD UP. That part about messing up a trimix blend and it ruining your whole weekend actually hit me. I thought gas blending was just like, follow the numbers on a chart and you're fine. What happened, did you get a bad headache or something? 130 feet already sounds deep enough without worrying about your own mix being wrong. Now I'm scared to even try blending my own.

ben4861mo ago

yeah so helium is basically mandatory past 130 feet if you wanna stay clear headed. I run a 20/20 mix for 150 foot dives on wrecks and it made a huge difference - no more feeling "drunk" or getting tunnel vision. the narcosis hits different for everyone but once you push past 100 you're playing with fire if you skip it. get a proper gas blending course before you mix your own though, I screwed up a trimix blend once and it messed up my whole weekend.