Posted by Joe R on November 20, 2000 at 00:04:54:
In Reply to: Re: 'an alert for those switching to a long primary hose...' posted by Frank, AADIVER, Farmer on October 30, 2000 at 13:42:26:
I use 50% almost exclusively in my pony bottle this gives a normal MOD of 1.6 at 73fsw, BUT IF doing a verticle ascent to the surface per ANDI's training recommendations it can be used as deep as 100FSW (PO2 of 2.0), since the PO2 wiill be decreasing steadily and high exposure would only be for a short period. (check NOAA table they allow even higher PO2)
Remember to take an O2 hit the 3 main variables are PO2, time of exposure, but the primary catalyst is the PCO2. If your CO2 loading is low its unlikely you will experience an o2 problem, that the primary reason most tech agencies teach 1.4-1.45 for bottom mix (to be reduced by modifiers)and 1.6 for the deco mix (since you are presumably at rest)
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