In Defense of Pony Bottles

[teknitroxdiver]

I don't have a point - I'm not the author of the text, it was just something I found interesting and passed it along to the board.

Ah. Gotcha. Maybe next time say so in the original post, to avoid confusion. Where did you find this?

 

[Cobra852]

I've been considering getting a pony what are the opinion's on mounting up or down?

 

[Snowbear]

I've been considering getting a pony what are the opinion's on mounting up or down?

A search for pony AND mounting should give you more opinions than you can read in a week

 

[teknitroxdiver]

What size are you getting? The reason I ask is that if you're getting one that's long enough, it's best to clip it under your arm, instead of a tank mount. This way it's out of the flow of water so it doesn't add any drag, and it gives you great access to the valve and reg. I'd say a 19cf would be the smallest you could comfortably sling.

If you get something smaller than a 19, it would probably work best to mount it valve-down on the main tank. This way you can reach the valve fairly easy.

Of course that brings up the issue of size. The smallest pony, at 6cf, is too small to make it worth your effort to bring it along. These are usually only used for argon drysuit inflation. The next two sizes, 13cf and 19 cf, are the same diameter, just a different length. To be exact, the 19 is 4.5 inches longer than the 13. So if you're picking between these two I would go with the 19, since you can then sling it under your arm, and have more air in a not-much-bigger package.

If you move up in size from there, you have the 30cf and 40cf. The 40 is too big for a pony bottle, it's usually used as a deco bottle or a stage bottle. The 30 is 3 inches longer than the 19, and 4.9 inches around. This is pretty large for a pony, I would only get it for dives in the 110ft+ range.

Here's a chart of all Luxfer aluminum tanks: http://www.scuba-necessities.com/scuba-gear/images/luxfer_imperial.jpg

Do a search on here for pony mounting or something like that and you'll find a ton more to read about.

 

[HawaiiDiver]

Ah. Gotcha. Maybe next time say so in the original post, to avoid confusion. Where did you find this?

A friend of mine wrote it. We both use ponies now and then, and he just found arguments *against* ponies in rec dives rather simplistic and ill-informed (as I do). But to each his own...

 

[AlHolbert]

teknitroxdiver wrote: "So if you're picking between these two I would go with the 19, since you can then sling it under your arm, and have more air in a not-much-bigger package."

Are there any existing sling bottle kits (Halcyon, Dive Rite, etc.) which would work with a cylinder as small as a 19? They all seem to be designed to work with 30's/40's and larger.

 

[teknitroxdiver]

I don't see one on the Halcyon or DR page, but you could easily make one yourself. All it is is a rope with a snap on each end, that you run under a hose clamp at the top and bottom of the bottle. And you can cover the hose clamps with something to keep them from scratching your suit. Let me look at some other places for a ready-made version...

 

[teknitroxdiver]

Well I take it back about H not having one. Looking at the design you should be able to just tighten the hose clamps down more to adjust for different bottle sizes, and maybe make the rope shorter.

This website shows how to make one, it will be well worth your time spent making it to be able to tuck the bottle under your arm
http://www.technicaldiver.com/stagebottle.html



Here is a picture of a 40cf size bottle in use:
http://www.halcyon.net/images/stage_detail02.jpg

The 19 would hang the same but be a little shorter.

 

[matt_unique]

"If you think you need a pony, you really need doubles.

If you don’t need doubles, then you don’t need a pony.”

Oh really?

1) “You don’t need a pony bottle because your buddy is your backup.”

Response: You should be as self-sufficient as possible, with or without a buddy, and embrace the concept of self-rescue in all but the most extreme emergencies. Expecting your buddy to bail you out of every difficult situation is irresponsible. Even when diving with a buddy, you should be self-reliant in mindset and gear configuration. *You* should be your own backup in most circumstances.

2) “You wouldn’t need a pony bottle if you developed better gas management skills.”

Response: Your gas management skills are irrelevant since a pony’s primary duty is to provide complete redundancy in case of primary breathing system failure, not to compensate for poor gas management.

3) “Pony bottles are an entanglement hazard.”

Response: Compared to a single tank, a pony does theoretically provide more openings for entanglements. However, they are no more, and perhaps less, of a hazard than diving doubles. In addition, many technical divers mount their argon drysuit inflation cylinders in the exact same manner as a pony bottle and it has not significantly increased their chance of entanglement.

4) “Ponies increase drag.”

Response: When mounted properly close to your main cylinder, they are far more streamlined than the doubles used by technical divers and only marginally less hydrodynamic than a single cylinder.

5) “You cannot manipulate the valves on a pony bottle.”

Response: While it is true that operating the valve on an upright back-mounted pony is difficult (though not impossible), mounting the cylinder inverted remedies this issue. If using an upright bottle, leaving the valve on allows immediate access to your reserve gas. Since the reserve is not figured into your gas supply during dive planning, if a leak or unmanageable freeflow does occur, the dive can be terminated (if desired) without affecting your primary gas supply.

6) “You cannot hand off a pony to a distressed diver.”

Response: The primary purpose of a pony bottle is to provide redundancy in case of catastrophic failure of the diver’s primary breathing system, not a tool to manage someone else’s out-of-air emergency. However, many types of pony mounts have quick-releases that enable a pony to be handed off if the diver so chooses.

7) “A pony adds unnecessary bulk.”

Response: A 13 or 19 cu. ft. pony, perfectly adequate for recreational situations, adds little bulk or weight to a rig while adding an easy-to-operate, completely redundant breathing system. On the other hand, switching to doubles creates a very significant increase in bulk, drag, complexity and cost to a BC, and requires that the diver learn additional skills to manage the doubles effectively.

I'm part of the choir on this. Your text is right on target. Some people will still choose to rely on someone else for their own safety.

 

[matt_unique]

teknitroxdiver wrote: "So if you're picking between these two I would go with the 19, since you can then sling it under your arm, and have more air in a not-much-bigger package."

Are there any existing sling bottle kits (Halcyon, Dive Rite, etc.) which would work with a cylinder as small as a 19? They all seem to be designed to work with 30's/40's and larger.

Dive Rite covers just about every size tank including 13's and up. I use the DR systems to sling 13's, 30's and 80's.