list your pony bottle size options / reasons

[usediver]

this is to list reasons for each diff size  .. " share air",  13, 19, 30,  40 cf sizes
  to help people choose size for their needs...
-please list size and some positive reasons for it. -
  thanks 

[Mr.Pitbull]

40..... well, because there is 40 cubic feet. If you really end up needing your pony, wouldn't you rather have all the reserve you can.

[Terry]

             I agree with the Dog on this one, but on deeper dives like on Isle Royale, or most overhead enviorments, usually like to wear doubles. I carry a 30cf pony, have a decent breathing rate, and have found it sufficient, small enough to not be in the way too much, still easy enough to hand off. Would'nt ever invest in a "spare air" WAAAAY too little in volume for anyone in ANY emergency at 100' leaving nothing for the depth (above 30') requiring the slowest assent. (Seriously first breath at 100', second at 60' YIKES!!!! for someone who might be on the verge of panic) Cylinder cost on this group of pony's is typically the same, so would recommend a pony on the larger end of the scale.

[arcFlash]

Steel 50 is too heavy to forget about but it works 2 ways on a dive. It's large enough to take 20cf out to add a bit of BT if you find something worth hanging out for and it still contains 30ft for 'quick' exits but it's not optimum as such, I don't reach for it unless I know I will breath it to extend BT. Don't buy. If you get a deal on two, twin them or leave it for some sucker. They are very popular as small twins.

AL40 nice. Can't go wrong. I wish I had 3.

Steel 72, also brilliant. I clip the head of the tank to my waist (it floats a bit behind me) for the first part of the dive and move it to the shoulder to breath. It can add 40+ minutes to many of my dives on an AL80.

AL80, preferred by many cave divers and I believe the standard for Wakulla (GUE,DIR) dives. I'll try an AL80 soon but I expect it to be better than the 72..

AL30 too small for me, also too short for my torso.

[DetectorGuy]

There are pros and cons to everything and it depends on how you intend to use the pony bottle. I try not to buy much of anything that has a "dual role" because what ever that equipment is, would not be able to do both functions perfectly and will have some sacrificing qualities. I use a 19 CF pony attached to my Alum 80. I don't do planned deco dives and use it only as a redundant air source in the event I run out of gas on my primary source. If I was tangled up and out of gas I would literally spend the rest of my life wishing I had a bit bigger "bail-out bottle". Proper air management, and practicing self rescue skills often, would minimize these risks from happening at the same time. The 19 CF works good for me as it is less drag than a 30 or 40 CF stage bottle dangling from my torso. The 19 CF will get me up from 100' safely on its own. With the short hose to the second stage it does not lose much air while bleeding it off after a dive. I only top it off after every 20 dives or so. My opinions may not be correct but thats the way I look at it.

Some of the draw backs to using a 19 CF attached to your main tank:
1. You can not hand it off to your buddy (which can be a plus as You can not drop it while doing this)
2. It has 1/3 as much air as a 30 and 1/2 as much as a 40. (depending on your SAC rate, depth or distance to the ice hole, you might need this extra air in a true "out of air" situation.)
3. The short hose on mine makes sharing it with your buddy tougher (comfort does not matter to me during emergencies)
4. The small button pressure gauge on mine attached directly to the first stage is impossible to see during the dive. (to me this is irrelevent as I check the pressure prior to the dive and when I switch to it, I already have more important things to take care of.)
5. The small stature of the 19 CF doesnt look cool like a 30 or 40 CF 8)

[grumpie]

The size of a pony bottle is determine by what your doing and your SAC rate. How many know what their SAC rate is? I will bet not many, dont for get that it will change when TSHF. Its like Nitrox stickers on their tanks its all show and NO GO. How many do dive planing and how many just jump in the water and go.

[doug67]

Spare air. It serves the purpose. It works for for what its made for. Why would I carry a 40 or 30 around on a 20, 30 or 40ft dive. You have to look at what your doing. I feel safe with the spare air for all my deep and ice diving. It will get me to my dive buddy or the ice hole in plenty of time. I dive within my NDL so a direct accent to the surface dosen't worry me. My 2 cents.

[arcFlash]

I use the larger button gage on my rigs. $35 from Oxycheq (OMS is $65) and you can read them on a dive. I know within 150psi so I can split up a pony tank over 3 dives if I'm using it to hang with guys on 100's.

PS
I know my SAC rates.

[grumpie]

Arc flash, Its a shame not many do.

[Raysh]

i also know my sac rate. i use a 40 mostly depending on depth and gasses used but also have 80`s if i need them.