I would echo what Bama said. Because I deal more with the regulator servicing side, I would be stronger in my admonition that elevated O2 mixes should only used with properly cleaned regs. The exact point where the petroleum based O-rings and lubricant become combustible will vary with ambient temp., atmospheric press.(all be it slightly), etc. I have heard from many sources that anything below 30% O2 is safe. My personal feeling on this is that ANY ELEVATED Oxygen breathing mix should have properly cleaned regs. This is overly cautious, I admit, but I have been the witness of carelessness around Oxygen, so have adopted this cautious mantra.


The tanks: go with what suits your style. The expense of doubling up 40's seems excessive for the pay-off, but you alone know this. I would encourage you however to dive several set-ups to be sure. An option my be to double up some old steel 72's..... just a thought.

As for the last point, I'll let Bama chime in, although I know what he is referring to. I personally dive a ppO2 of 1.2 ATA (working), and use 1.6 ATA ppO2 for deco. I think there is something to be said for the deep stops. (This is not applicable in two of the latest accidents) The important thing to consider here is 1. Start Slow!!!! there is no rush. Let your body get acquainted with these mixes, under pressure. Learn how YOU respond to different scenarios! 2. The Internet is NOT the place to learn how to deal with this! Go to individuals well acquainted with different gas mixes and LISTEN to them. 3. We each respond differently, even on different days, so PROCEDE WITH CAUTION AND LISTEN TO YOUR BODY!!!! 4. DO NOT UNDERESTIMATE the value of physical fitness. For you personally, this may not be so much an issue, but for many others it is a major issue.


I hope this helps.