What size pony do you use?

[spectrum]

I am most interested in covering off cold water free flow situations. I do not do penetrations or cave diving, no interest in tech or trimix. In warm water I am ok with my buddy.

In the cold water my concern is the potential for free flowing my buddy's 1st with two breathing off of it. Really just looking for enough gas to do a normal ascent and safety from 130 feet. I believe that a 30 is sufficient for this (my) purpose, perhaps even a 19,just looking for a sampling of what others do.

Appreciate all the replies / opinions.

130 feet with a 19 is not a sound choice.

Take a look at this old post based on a 99 foot incident and I ended up a plausible need for 22 cubic feet. At the time I talked myself into rounding down to a 19 based on a lot of fluffy assumptions. In rethinking this lately I realized 2 big misses in that post.
1) Assuming that you drill in the deployment of your pony it's likely that the fill will not be 100% at the moment of need. Being down 200-300 PSI is quite possible.
2) While you may not need to plan a 500 PSI reserve 200 or so is prudent to make sure your regulator delivers to the end and to account for gauge error.

Taking those 2 revelations into account a 19 clearly is inadequate at 99 feet. I don't have time right now to revise the numbers but 30 CF at 130 is probably at best on the edge if there are any issues to resolve prior to ascent.

Pete

---------- Post added November 21st, 2012 at 07:11 PM ----------

You might want to see if there's really that much difference (trim, weighting, and effort-wise) between slinging a 30 and slinging an 80. If you need extra gas, you have to carry a tank, an attachment system, and another reg. The bottle size itself just doesn't matter much once you're in the water, IMO, and if you have an 80 you can use it for other things on dives where you don't need it for redundancy. Conversely, I can't think of anything I'd use a 30 for aside from an O2 tank, and they don't cost much less than an 80.

As one who mainly shore dives I can see plenty of cause to avoid an 80 if it's clearly more than you need. That being said, we have slung AL80s as extra air on extended dives and I agree that it's not unwieldy. In fact my wife liked it!

Pete

 

[tye1138]

I use to run a side mount 32cf steel pony bottle with a quick release 2nd stage.

For me the biggest reason to have a pony is for ditching. So to have it behind you, is kinda silly and isn't going to do you any good back there if you get hung up somewhere.

I use to wear a weight harness with a little D ring on the top and bottom. So what I'd do is strip the BC off and of course I'd be very positive at that point. So I'd disconnect the pony, hook it up to the harness and I could then be a whole hell of a lot less positive.

I never had to use the bloody thing, not a single time! But its very comforting to know its there!

In the current rig I'm building, because I'm running super small doubles, I'm going to be running a completely redundant air source using an A/B system and then a smaller side mount (again steel) emergency ascent bottle.

 

[GrumpyOldGuy]

I use 0, 6,13 or 30, it all depends on the situation.

Some will always say underwater they big bottles are barely noticeable. To the degree you don't have the weight, its true and so they will claim more is better.

I like small, its easier to handle topside and more likely to be used on a regular basis. I use a 13 for 75' dives, a 19 would be a good choice for 100' dives, 30 for 130'. The 6' is used only when I have severe luggage weight limits as its under sized for most dives, but like a .380ACP, its better than nothing.

 

[oldflounder]

I am considering buying a pony to provide an additional measure of safety over and above the buddy backup. Cold water diving down to 6c - 7c, and to a depth of up to 130 feet. My regs are good cold water regs, Apeks, but of course that is no guarentee.

What size pony do folks typically use?

If you are going to that depth in that temperature I would think you would want to carry the largest size you can handle.

For my type of diving [less than 60' shore diving] I use a slung 13 for the comfort and convenience. I also own a 19 and 30 for deeper. But for my everyday diving I have the 13 along - to go down to the bottom with if I have an issue - not to go up. I call it my think-time bottle. It is said that many underwater issues with the equipment/entrapment/freeflow/partially shut valve/etc. can be resolved while down under. There might be no reason to rush to the surface. Knowing that I have that little bit of extra air in arm's reach hopefully keeps panic away a little longer and gives me a few minutes to sit on the bottom and think of a solution to whatever the problem might be.

And hopefully, in an OOA, I could hand it off to my buddy instead of doing an ascent with an insta-buddy.


Anyway - the size you need depends upon the personal diving situations you plan to encounter that day.

 

[tomfcrist]

I have a few different sizes, but use my 40 most often. If I had it all to do over again, I would have bought the 40 and a dedicated reg for it , foregoing the process of buying what I thought I needed only to find out it isn't big enough. A 30 or 40 is MORE than enough for rec diving, but when you decide to start doing tec....you have a usable deco bottle.

 

[drbill]

For recreational depths I carry a 19, but am considering a 30 or a 40 in the future unless I go to sidemounted double 80s

 

[Nemrod]

0, 19 or 30 here. Others may disagree, my SAC rate is not their SAC rate, I can do fine with a 19 down to max sport diver limits. I do prefer a 30 below 100 feet and if I need anything bigger than that then I go to doubles, either manifolded or independent.

N

 

[scubadada]

Slung 19 to recreational limits. More than adequate for my air consumption. To each their own.

 

[gcarter]

Supplementary question: Have you ever had to test the sufficiency of your pony? Did that cause you to change / modify your opinion?

TIA

 

[lowviz]

Supplementary question: Have you ever [-]had to[/-] test the sufficiency of your pony? Did that cause you to change / modify your opinion?

TIA

Yes, No.

Results: At 80 feet, at double my SAC rate, 1 minute to sort things out at depth, 30'/min ascent, a 3 minute hang at 15-20 feet will just empty a 19.