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Old May 11th, 2008, 01:38 AM   #11
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according to NAUI Tec max suggested is 75 fpm
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Old May 11th, 2008, 01:51 AM   #12
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WHAT!?!?!?!?!?!? man I hope your joking...
To a point, yes... after that... NO!

By the tables with EAN 28% (on a flat table...) This diver has a bottom time of 15 minutes... not 4:45 minutes... The idea of calculating descent rate and ascent rate with a computer is rediculous. The computer calculates these on a minute, by minute basis and supplies the diver with correct data based on thier actual dive, not on a flat table...
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Old May 11th, 2008, 01:55 AM   #13
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WHAT!?!?!?!?!?!?
ok so 3500-1500=2000psi used with a tank factor of 4.33 means that you used 86.6 cuft of air. 86.6/270 minutes means that you have a surface gas consumption rate of .32, and that is assuming that you are actually sucking air out of your tank while floating on top of the water... HIGHLY SUSPECT!
It is obvious that you have never been on a dive to VB (15' dive, and not much movement)... Most divers get 2 hours from a AL80 at VB (including my 16 yo son)... So, your math is suspect for "real" diving
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Old May 11th, 2008, 02:01 AM   #14
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((3500-1500)*.0432)/270=.32 cuft/minute at 0 ATA
tank pressure - remaining air) * tank factor divided by bottom time
check the math, Im tired, maybe I goofed up....
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Old May 11th, 2008, 02:05 AM   #15
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((3500-1500)*.0432)/270=.32 cuft/minute at 0 ATA
tank pressure - remaining air) * tank factor divided by bottom time
check the math, Im tired, maybe I goofed up....
Im a bit confused by your math. Probably as I use metric but..
if its 149CF @3500psi then at 1500 psi its 63cf no??
149/3500*1500=63.8cf
63.8cf/270minutes= 0.236 CF per minute which is indeed pretty low at the surface.

And shouldnt it be @ 1ata? or was this in orbit?
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Old May 11th, 2008, 02:20 AM   #16
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Im a bit confused by your math. Probably as I use metric but..
if its 149CF @3500psi then at 1500 psi its 63cf no??
149/3500*1500=63.8cf
63.8cf/270minutes= 0.236 CF per minute which is indeed pretty low at the surface.

And shouldnt it be @ 1ata? or was this in orbit?
Not to mention the 10% overfill we usually recieve in the southern USA...
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Old May 11th, 2008, 02:24 AM   #17
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What are you going to do when/if you hit deco obligation and have a 1st stage failure? Narcosis? Burst disk failure? Please, anyone who's considering this dive, think long and hard about it! Let's keep this dive as a "what if".

I did a dive back here a few months ago very similar to this one and had dive buddies good enough to be honest and tell me how stupid it was, I lived and nothing even bad happened, but had any one problem arose, I might not have.
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Old May 11th, 2008, 02:32 AM   #18
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As the OP stated its an exersize in planning. He was not planning an actual dive.

So you get 10% over fills on top of 3500 psi? 3850 psi fills? so it wasnt really 149 CF then was it? More like 164cf
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Old May 11th, 2008, 02:44 AM   #19
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So... your math is off, because your calculations are off, because everyone breathes the same... and every dive should be the same.. and every diver should be the same... etc... etc... etc... worthless waste of time...Welcome to planning your dives in South Florida, USA....
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Old May 11th, 2008, 02:45 AM   #20
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As the OP stated its an exersize in planning. He was not planning an actual dive.
Yes, the OP did state that. I just wanted to mention some of the dangers so no one else would assume the math was correct and try it, that's all. I think it's a great exercise.
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