True, but that 5cfm consumption rate changes dynamically because I am going up at a steady 40 ft/min or more at that depth, so its not like I am going to sit at the bottom and suck down my pony at 4-5cfm (and I know my consumption rate does not double in an emergency from experience, so it is more likely around 3-4cfm). So my first breath or two might be at 4cfm, but by then I am up 10 feet or so.
And who is talking about 3cfm for a pony? I bought a 6cf pony, which I thought would give me about 4 minutes to ascend ... though I am now considering upping that based on the previous posts. Read my post please before attacking. And yes, I meant boyle's law. It has been a while but I can still do the math, its just that the equations involved, when you are moving and partial pressures and relative gas volumes (and ascent rate) are changing constantly, get a little complex and involve some differential equations that I would really prefer to just find rather than create.
) So you've now been at 5ATA for a minute, with an RMV of probably at least 1 . . . 5 cubic feet just disappeared. Now, assume you are icily calm and ascending at 30 fpm, and you will not make any stops. You have 4 1/2 minutes, at an average depth of 65 feet, or call it 3 ATA -- that's between 7 and 14 cubic feet of gas. This is why people choose at least an Al19 for bailout, and most people decide on something bigger, because the last thing you want is to run out of gas TWICE.
