#164
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Eqeao - 10/23/2013 7:34 AM
Yeah, the limit to 150’ is really about narcosis. Narcosis and ’deep air’ tend to spur some strong feelings in the community (as to how deep is acceptable, etc). Generally speaking everyone concedes that narcosis does take effect, in most conditions, at 100 greater. At those depths your ability to problem solve starts to decline. This may not be noticeable, but it’s generally accepted that it happens (and there have been multiple studies, etc). Some training agencies (including TDI) feel that with enough training and ’muscle memory’, you can mitigate that risk. Others (like GUE) don’t want to cross that line and teach Trimix for all dives below 100’.
Generally speaking people start doing decompression on a bottle of 100% o2 at 20’. But there are MANY issues with that, not least of which is the increased chance of a tox event if you do it wrong.
Gas management is critical, and a good article about it can be found here:http://www.nwgratefuldiver.com/articles/gas.html
I would also say that for me, on a dive like that, team selection, planning, and communication is key. I want to know that my teammates are on the same page.
For what it’s worth, in our class, we’re only going down to 130’, and the instructor will be on trimix, to mitigate risk.
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