19 or 30 cubic feet?

[rye_a]

To be more specific:

I'm planning to use this as a back-up air source for diving in high mountain lakes (8,000') at depths no greater than 60' (usually much shallower) and always within no decompression limits. Because of the altitude I would think that it would be important to have enough air in my pony for a safety stop in the event of complete failure of my primary set-up.

Since the purpose of my pony will be entirely for emergency situations and I don't plan to use it, I prefer the idea of a tank mounted system for ease of use and carrying.

 

[scarefaceDM]

EDIT - I was a little slow...

A 30 is the BEST option. A 40 is a bit of overkill but the way to go if you do plan on pursuing tech diving. More gas is always a plus.

Look at how you dive, where you dive and with whom you dive. Factor in how well you plan your dives. How much air you suck back and how this can affect your overall choice and as to why you need a redundant air supply.

Once that has been considered. Your next move is to mounting.

I use to mount my 30 onto my Primary tank with Pony Tamers. I had to counter balance the extra weight as to not roll like a log to one side. I got fed up of that and went to a sling. Slinging a redundant air source is very easy, and also very cheap. for less that 10$ you got a sling kit. And a slinged bottle sits under your arm and slightly upwards. It is out of the way. It is also really easy to use and hand off your redundant air source to someone in need.

what ever you choose it is worth doing it right - once. Cheaper this way.

 

[Hank658]

From what you describe the 19 might be fine. If you can borrow one that might be the way to try it out. Mounting, trim considerations, valve up or down are all variables. If you can put a reg with a SPG on a regular length hose you could try the system out. Dive to 50-60' and with your primary nearly full switch regs to the pony. Keep your primary reg quite handy though!! Do a normal ascent with a safety stop and see if the pony lasts long enough for the way that you breathe. This is why keeping the primary from your main tank is very important- if the pony doesn't last all the way then it's back to your main tank.

Oh yeah forgot to mention this first- ensure that you and your buddy go over this procedure and that you are in agreement that this will be the dive plan!!!

Pony tanks are not that expensive. If you do need a 30 or 40 it's not that much more to buy another one. Most folks I know have a bit of a selection.

 

[jim T.]

I believe that a pony bottle/bail out should be slung.
If the system is leaking it'll leak right in front of your eyes. If you free flow you can easily feather the valve on and off. If you need to ditch your main rig due to an entanglement you have something to breathe on the way up.
If you vacation dive somewhere deeper, (most Caribbean dives are in the 80' range or so) you'll have redundancy. You can pass the bottle off to an out of air diver.

I use a 30cf slung. It's easy to get used to. Doesn't get in your way like it would seem to on shore. I can stow the reg on the bottle itself (in bands) or around my neck giving you even more options. I charge the reg and then turn the valve off. It's right in front of me during the entire dive (with a 6" spg hose) and it takes 3 seconds to turn it back on.

On your back, it may leak before you check your spg. If you have no spg or just a bottle mounted miniature spg, you may not know until you bail out to...nothing.
If you get entangled,it may be harder or impossible to release, the tank mounted pony bracket it may be harder or impossible to reach the valve.
Those potential issues made me choose to sling a 30cf. I actually wish I'd heeded others advice and gone with a 40cf.

If you choose to solo dive all of the above become much more important points. I sometimes solo which has influenced my choice in slinging. As we all know, our buddies are not always where they should be. Having a larger pony give you a much greater/safer comfort zone in choosing to swim to an errant buddy for help or calling the dive than a smaller one which allows only surfacing alone.

People talk big about CESAs but I'd rather take a more relaxed and safer path if it's available. I'm not a "spring chicken".
Could I do one? Sure! Would I rather have enough air to not have to? Sure!

On a boat dive, my DIN "wheel" connector hit the ladder (I guess...) during my giant stride. It loosened just enough to
leak. I saw that immediately upon submersion and fixed it right then. If it had been on my back, it would have taken much longer, I would have lost more air and I would have considered calling the dive or at the very least had to decide whether or not to call my dive without my intended redundancy. Because it was slung, no problema.
Did I have a buddy? Yes but it was an "insta buddy" with unknown proclivities, on a vacation dive.

Just some more points for you to consider when making your choice. Hope it helps.

 

[rye_a]

OK...I've been talked into slinging my pony. Anybody have a picture of how to build a sling for a pony?

Also, I am planning on using a Zeagle Razor 1st stage and an Apeks Egress octo that I already have for the pony 2nd stage (switching to a Zeagle Octo-Z for my octo). Is it a bad idea to use a high quality octo for a 2nd stage on a pony?

 

[scarefaceDM]

here ya go

I did mine for under 8$

http://dir-diver.com/en/equipment/stagebottle_rigging.html

OK...I've been talked into slinging my pony. Anybody have a picture of how to build a sling for a pony?

Also, I am planning on using a Zeagle Razor 1st stage and an Apeks Egress octo that I already have for the pony 2nd stage (switching to a Zeagle Octo-Z for my octo). Is it a bad idea to use a high quality octo for a 2nd stage on a pony?

 

[matt t.]

If you are going to sling it, go for the 40.

 

[nereas]

Your pony may be deployed as deep as 130 fsw. Therefore you would normally want pretty good first and second stages on it.

For a sling, go to a tech scuba store and ask for a sling assembly for a deco bottle. Then connect this to your pony. It has 2 bolt snaps on it, one high and the other low. These are then connected to 2 D-rings somewhere on the front or sides of your harness/BC. Make sure the B/C has D rings on it for this, if you are not yet using a hog-harness.

Some people like to sling the pony on the left, others on the right. I like the middle, with a pony, because that way it does not throw off your trim.

I rarely dive with a pony however. Normally I have either a buddy (and thus no pony needed), or else 2 deco bottles (one on either side for balance and trim). A pony is really for solo gear, and then only if you are weak on your ESA (emergency swimming ascent -- sort of like freediving but on scuba).

 

[hlsooner]

I will share my own experiences. I have used a 30 cu ft. pony tank for about two years. It has always been mounted to my main tank using a Quick Draw Bracket. www.quickdrawbracket.com The system is barely noticeable under water and not difficult when changing tanks either.

Despite the success with this rig, I am in the process of switching to a 19 cu ft. tank which I will be slinging. The slung tank is easier to hand off, which is where the pony is most often useful. I have never used the gas in it in over a hundred dives, but others have used it close to ten times (we have a lot of tourist divers in Miami). Also, after evaluating, I believe 19 cu ft. will allow me to comfortably surface from any emergency at recreational depths as long as no overhead is involved.

 

[Nemrod]

I sling a 19 for deep solo (100-150). I sometimes use a 30. I have purposely switched to the pony from 130 feet to simulate a failure and at least for me I made a leisurely ascent complete with saferty stop and one pretend deco stop. A 19 is plenty for no deco sport diving. The advantage of a 19 slung is that it essentially dissappears as if it is not there. I imagine it would provide an equally low profile mount to your tank. I used to mount a 12 on my tank on homemade mounts but now prefer slinging. I rarely do intentional deco these days but when I do I go to a completely different set up, like my independent double 72's or double 50s on a manifold with a 30 or 40 slung or twin Faber 85 LP and a 40 or even a 63/80 slung. But, I don't do that much anymore.

Slinging is fairly new to me having grown up diving independent doubles. I have one rig that allows two steel 72s and can then center mount a 30 or 40 aluminum, diving this I switch back and forth so that in theory I am back on the boat with 1/3 or more in each 72, a full 30 cf pony and do my deco now on a slung 40. All with there own regs.

Usually when on doubles I am using my old Dacor Seachute BC or my new SeaTec BC, both are horsecollar type. That way I don't have a huge wing making drag and having to own different wings for each rig.

Another advantage of steel 72 independent rigged is that you have over 140 cf of air (cave fill even more) and the bands are made very narrow so the rig is very streamlined and does not hang out in the breeze with a huge wing haning even further out. No huge valves hanging out either, if you planned correctly even losing all the air in one tank since it is fully independent you should always have enough air in the remaining tank to get home. Very streamlined and simple.

N