seeker242
Contributor
Hydro is the training wreck for many local TDI AN/DP classes and generally always done on air.
Hydro Atlantic without Helium?
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Mouth Breather
Contributor
I don't know that I'd bother with 22-23%...it won't change your profile much. I've done the hydro on air quite a few times and have managed any narcosis just fine with ~30 min bottom times. I keep things simple and ask myself, "am I being stupid/slow?" throughout the dive.
This. For the last dive of AN/DP we did the Hydro with 2 students and 2 instructors, so there was a constant check on us students. I do not believe I was narced (and there was no obvious evidence that I was). But everyone is different. If you go for the Hydro Atlantic, make sure you have an experienced buddy who has done deep air before. It's hard to predict when Stevie Wonder will show up.
OTOH, we were wearing 3mm full wetsuits and I didn't notice the temps below the thermocline dropped to 61 F. I thought "it's a little cooler down here", while the other 3 on the dive were acutely aware of freezing their butts off. I'll chalk that up to the my excitement about the dive, not being narced, but who knows?
PfcAJ
Contributor
No one gets smarter underwater.
Some folks are starting out questionable.
Some folks are starting out questionable.
Ryan Mcshane
Contributor
Caveeagle
Contributor
No kidding. I have been on several tri mix training In Ginnie and Little River. (100'ish) and the reaction is more predictable than politics! Wow! I don't remember seeing that before!
Is 150' on 21/00 inherently unsafe.. no. But anyone denying any narcosis at 150'. Is unsafe! Can it be manageable sure, but, why?
flymolo
Contributor
Safety aside, wouldn't being able to recall the dive better, be worth it?
I got hung up on the railing in the engine room I think at 158ish and it took deliberate thought to simply back up and keep going on 23%. It's a great Helitrox dive... I top off my 21/35 Lowrance leftovers with air for the Hydro.
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