Quote: (Originally Posted by
Mixaddict)
...Have been doing some dives in locations where helium in unavailable (or at least very difficult to get!) For me personally, it has seemed while diving CCR that I have been feeling the narcosis at more shallow depths than I typically do on OC, and basically wondered if other divers felt the same way. But here again, as you well know, it comes and goes differently on different days! My suscpicion is that the perceived narcosis level increase on CCR for me is possibly more about task loading than actual narcosis increase?
Hi Randy,
I tend to agree. A 50m CCR dive on air dil makes me feel more narked than OC every time. I used to do a lot of OC deep air with bounce dives up to 100m. Over the years my ppN2 tolerance has decreased dramatically (or i have become much wiser). Nowadays my cut-off point is 50m for both OC and CCR on air.
On very good conditions, I still may spike down to 65-70m for a short while when on OC. IMHO, ppO2 exposue is not a real problem on OC air - at least to my own physiology. I have clocked many hours on O2 CCR at ppO2 values comparable to deep air with no problems.
The real problem is handling ppN2.
/GKAM