So I don't know why anyone would want a 13, except maybe that it's shorter...?
Oh, I dunno..... it's a pretty good size for drysuit inflation....
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
So I don't know why anyone would want a 13, except maybe that it's shorter...?
Which is why I spent $10 more to carry 2# heavier tank and 50% more air.Because you should plan too have too much gas in a worse-case scenario, not the opposite.
+4.9 cubic feet
+4.5 cubic feet
+3.6 cubic feet
+2.8 cubic feet
+2.5 cubic feet
+2.2 cubic feet
+1.9 cubic feet
+1.5 cubic feet
22.4 cubic feet skipping the 3 minutes @ 20 ft, or was there something else I was supposed to know about this?
Which is why I spent $10 more to carry 2# heavier tank and 50% more air.
Another way to view a 19 cf is that it's 1/4 of a 80 cf since they are really not 80s, or equivalent to to 750# of 3000# of a 80 vs a 13 cf equivalent to to 500# of a 80. The 19 seemed call for 130 ft diving and sometimes I wish I'd got the 30.
I hope your math on the steps was correct. I just added the lines out of curiosity. So it's 22.4 cf without the 20 ft stop...?Oops, was my math off? Thanks for the correction. I made the adjustment above.
Would any of us actually stick to 30ft/min ascent rate if we were OOA and breathing on a pony??? Just posing a question. I know I would have a hard time with that. I would get to 60ft. really quick then start a slower ascent.
Would there be enough air in a thirteen cubic foot bottle to make an ascent from 130 feet, which would include a one minute stop at 30 and 50 feet and a three minute at 20, for a person like myself who is pretty easy on air most of the time?
My bailout ascent plan is to slowly head up to a 15' safety stop and hang around for 3 minutes, or until the 19 cuft pony is out of air (whichever is shorter) and then surface.
Garrobo:Would there be enough air in a thirteen cubic foot bottle to make an ascent from 130 feet, which would include a one minute stop at 30 and 50 feet and a three minute at 20, for a person like myself who is pretty easy on air most of the time?
So, the answer is 'No'. Even if I use a slightly less conservative calcuation (0.75 CFM SAC, and no diddling around at 130), I come up with the same answer - 'No'.Assume SAC = 1.0 if you're bailing out ... Assume ascent rate 30 feet/min with average depth halfway between
TOTAL REQUIRED = 24 cubic feet to get you back on the boat with 0 p.s.i. remaining
Which is why I spent $10 more to carry 2# heavier tank and 50% more air.
Good point. I think you're right. You can do a pretty slow OOA ascent from 15 ft, but easier to control with 100# to work with.I'm a little curious about this. So do you breathe the pony down until it is OOG and then surface from 15'? I ask because this seems counter to the advice that surfacing slowly is most important during the shallowest portion of the dive. If that was a consideration, I would assume that it's better to cut the deco time at 15' and surface slowly than to stay a little longer and then surface immediately because you can't breathe.
What do you think?
Yep, could call it that way too. More air is always better for me.Which is pretty much the same logic I applied to getting a 30 cu ft rather than a 19 cu ft.