Getting a pony, but have a few questions

[The Chairman]

Though I do think I may eventually change over to BP eventually. Just not right now.

Before you do, check out Zeagle's Express Tech. Its the best of both worlds for single tank diving, in my opinion.

 

[The Chairman]

I now sling a 19, and there's lots to be said for a 30.

I give AL30s to small peeps. I sling an AL40 or an AL80. If you're going to bring more air: bring more air.

 

[Marie13]

I give AL30s to small peeps. I sling an AL40 or an AL80. If you're going to bring more air: bring more air.

I’m small peeps. . Someone out at the quarry once told me I needed a smaller pony since I’m short.

 

[doctormike]

If you're slinging, no need to restrict yourself to 13cf, especially if you're solo. I started that way just because it was tank-mounted. I now sling a 19, and there's lots to be said for a 30.

Yup! Like it's 3/4 of a 40...

 

[rsingler]

Liberal RMV 0.7cfm
Add stress and double it to 1.4cfm
Make it 99 ft/ 4 atm = 6 cfm
Allow 2 min to problem solve = 12cf used.

Now relax to 0.7cfm (2.8 cfm @ 99'), and begin ascent.
Average of 2.8 cfm at 99' and 1.1 cfm at 15' is ~2.0 cfm. Ascent time at 30fpm is ~3 min, which is another 6 cf used.
Total used so far = 18cf

Now safety stop x 3 min @ 1.1cfm = 3.5cf used
Total used so far 21.5cf

Ascend from 15' to surface at 10fpm = 2cf
Total used so far = 23.5 cf

Finish with 300 psi in 19cf tank (1.9 cf), and total requirement becomes (oops!) 25.5 cf.

Lower RMV or shallower depth, and you might get by with 19cf. Longer problem resolution time (? entanglement?), and even 30 might not be enough.

Your results may vary.
Cheers!

 

[doctormike]

\

Finish with 300 psi in tank (1.9 cf), and total requirement becomes 25.5 cf.

Lower RMV or shallower depth, and you might get by with 19cf. Longer problem resolution time (? entanglement?), and even 30 might not be enough.

Your results may vary.
Cheers!

Not to mention the fact that a free flowing second stage at 99 feet will completely empty an AL19 in 37 seconds... seriously, I know that it's the same argument again and again about pony size (hey, what else do we have to do?), but why be so cheap with the gas?

 

[rsingler]

Not to mention the fact that a free flowing second stage at 99 feet will completely empty an AL19 in 37 seconds... seriously, I know that it's the same argument again and again about pony size (hey, what else do we have to do?), but why be so cheap with the gas?

Whoa, Mike!
OOA on backgas, AND
Freeflow on pony?
I think it's time to take up skydiving.

You know. Something safe.

 

[doctormike]

Whoa, Mike!
OOA on backgas, AND
Freeflow on pony?
I think it's time to take up skydiving.

You know. Something safe.

I also plan for getting hit by a bus on the way to the dive site. 3 is 2, 2 is 1, 1 is none...

 

[Cowfish Aesthetic]

Yup! Like it's 3/4 of a 40...

I'm think I'm sold on the 40 just because I can't think of a reason (for me) not to carry it. It's not too heavy for me on land, and it's not to cumbersome for me in the water.

 

[Fastmarc]

If you're slinging, no need to restrict yourself to 13cf, especially if you're solo. I started that way just because it was tank-mounted. I now sling a 19, and there's lots to be said for a 30.

Ok cool, Thanks.