Pony bottle size

[codecruncher]

As a pony I wonder if a 19cf might be small enough that you find you take it with you more regularly vs. not wanting to deal with it because of the size/weight/PITA factor.

Just a thought I've heard from other folks considering this as well.

Personally I have a 13cf I sling which is just barely enough for a non-deco ascent - I'd be more comfortable with a 19cf, but I got the 13cf dirt cheap at the time. I barely even notice it once I'm in the water.

I'd rather have a set of doubles or a {worthington X8-130 + a 19cf slung} might be nicer though.

Cheers.

[dwitt2n]

divingdeputy ...I'm curious on the 30...what is the average number of breaths your getting off them..?...   

[Omicron]

I know a few have mentioned slinging your pony bottle - in case you were wondering what was meant by that, check out this link.  I know what the website is...ignore that if you have any bias   I'm not a DIR diver either, but it's just a really good guide.  The advantage with this setup is, it's CHEAP.  15 min utes and $15 at a hardware store and you are set.  I can set one of these guys up in just a couple of minutes.

Top clip goes to your chest d-ring, bottom one goes onto your waist.  The tank sits tucked away really nice and accessible.

It's an option...instead of buying a pony bracketing system or something like that you can just go with this if you'd like.

Now back to the regular bottle size discussion.

[Vtach]

Folks, the best thing you can do to figure out what you need for a redundant gas source is calculate your SAC (surface air consumption) rate.  Once you figure out your SAC rate you can accurately calculate what your needs will be for a redundant gas source at depth by multiplying your SAC by the ATM of pressure and time at that depth.  Don't forget to multiply that result by 2 to account for an additional OOA diver (worst case scenario).

No offense to anyone but even a 19 cu ft bottle won't be of much use to 1 diver much less 2 divers OOA at depths of 100 or more.  SAC rates will be much higher in an emergency than at rest.

[Chris H]

Many, many breaths at 20ft, not even close to that many at 130ft.  Todd is correct in this one.  There is much more to calculating gas consumption than "how many breaths".

[codecruncher]

This might be of use to get you in the ballpark and then follow on w/ your own SAC rate and tank specs you are considering.

  (safe for work browsing)

Certainly illustrates the 30cf has a nice safety margin.

I've also found this article explained air consumption rates pretty well:

[arcFlash]

I'm new to stage bottles but I got a steel 50. It's long but skinny. I've swam it 6 or 8 times and I really don't mind it and with the extra size I can use it as a travel gas and switch to my main tank to increase my bottom time some and still have reserve.

I can't afford to have every size and it's not too big. I'm also 6 foot so I have the torso to carry the length.

About having gas for your OOA buddy? Wouldn't they also have a stage? That's 4 first stage failures or 6 second stage. That's a bad day. This assumes the original post of no-deco <130ft.

I'm open to constructive criticism.

[Chris H]

Don't use steel stages.    Too negative.  Try an aluminum 40 sometime, I think you will be pleasantly surprised.

[dwitt2n]

I am...aware of the dynamics involved in gas dynamics...it was a simple question of what was realized when the oh S*** factor hit 9.......

[DiveCaptDean]

used to sling steel....man how tiring....it used to pull like hell on my harness..it now spends its time on a friends SCR.......i am much happier with aluminum................................

in my opinion....a 30 is perfect for a pony bottle  and 40 is perfect to sling...a 19..is too small for much of anything..... and anything smaller is an argon bottle......
but this is just my opinion.....