Talk:Pony bottle

Pony Bottle also refers to small sized bottles of beer, at seven ounces or so.

Nantucketnoon (talk) 21:56, 7 May 2010 (UTC)

Terminology
I find it interesting that the definition for a bailout bottle has been changed to something no commercial diver would be allowed to use in my part of the world. It would also not serve adequately for bailout in anything other than a fairly shallow dive, with no decompression obligation. Clearly there are different meanings in different contexts. I would consider any cylinder carried primarily to allow the diver to bail out in an emergency to be a bailout bottle (cylinder if you prefer), and it should carry sufficient gas to get you from any point in the planned dive to a place where you can get a secure gas supply. Bell, surface, staged cylinder, whatever. I would class the Spare air type as a bailout bottle at the extreme low volume end, and a pony bottle as usually larger, but still a bailout bottle. For surface supplied diving the bailout bottle is usually carried on the back, and though usually between 7 and 12litres, may be as big as a twin 12litre for deep bell diving. An extreme range of sizes, from less than a litre to 24 litre, but bailout battles all. Because that is their purpose.

Pony bottle is a different matter. I dont have any references for what a pony pottle is or is not, but general usage where I live (South Africa) is that a pony is smaller than the primary cylinder, would only be carried by Scuba divers, and is usually, though not necessarily carried attached to the back mounted primary cylinder. Some divers would also call a sling/sidemount bailout cylinder a pony. They would probably not call a Spare air a pony. Does anyone have a good reference? Peter (Southwood) (talk): 15:07, 3 November 2011 (UTC)
 * I thought the definition (particularly in the first sentence) of the lead matched what I have come to expect from a "pony bottle". If you do Google searches for "buy pony bottle" you'll see the sort of offerings that are advertised for sale as pony bottles. LeisurePro for example sells aluminium ponies in sizes from 6 cuft to 40 cuft (what we would think of as 1 litre to 6 litre sizes) and that seems to correspond with my expectations. There's a decent article on the ukdiving.co.uk site from DIVE magazine that examines the practicalities of pony bottles.
 * If it's any help, I consider pony bottles a sub-set of bailout bottles. Like you, I'd expect to find them normally only for recreational scuba diving as an adjunct to a single larger cylinder in order to provide redundant backup. I'd always recommend slinging one along the left side from D-rings on the backpack/harness in exactly the same place as stage cylinders would go, although I know that ponies are also commonly attached to the main cylinder by various means.
 * Personally, I believe that a 3 litre pony is only feasible for real emergency use on shallow dives, and a 6 litre is probably borderline around 30 metres, simply because you can't estimate the effects of panic on breathing rate when the shit hits the fan. I'd also consider Spare Air a gimmick as I'd be confident of performing a free ascent from the sort of depths where a Spare Air is actually usable. I'd admit I'm somewhat biassed against "lightweight" redundant solutions as I've dived most of the last 20 years using twin 10-litre 300 bar cylinders with an isolating manifold and a 2-metre primary hose. On the other hand, I've witnessed six fatalities in that time, but never come anywhere near to running out of air with my gear. Sorry I don't have definitive references for you, but I guess Gene will spot this and provide some soon :) Cheers, --RexxS (talk) 18:21, 3 November 2011 (UTC)


 * I think I am getting a picture here. Correct me if I am wrong. It seems that your usage for "Pony bottle" is primarily that of size. A pony bottle appears to be a cylinder with a standard scuba cylinder valve, with a smaller capacity than usually used for diving, perhaps 7litres or smaller? The application as a bailout cylinder appears to be secondary to the size. If this is the case I now understand HowieKor's objection to the proposed merge.
 * In South Africa, a pony bottle usually means a smaller cylinder than the main cylinder, used as a bailout cylinder, but not a Spare air. This is an important distinction, and I think it should be mentioned in the leader paragraph if correct. In the 80's I used to do a lot of diving with single 7 litre 200bar or 6 litre HP cylinders, and no-one called them ponies, as they were the primary cylinder, supported on the harness or BC in the same position and same way as the more commonly used 10liter or larger cylinders. We are not big users of pony cylinders out here compared to the UK as I understand it, and I don't mind going with the majority usage as long as it is adequately defined. Is there a definite line between pony and regular cylinder? (how do you tell which it is?) For us it is simple, it is smaller than the primary, and has a different function, though there is another difference, some people here would call a deco cylinder a pony, i.e. it is smaller than the primary, and may be for deco or bailout. It would also not usually be called a pony if used as oxygen or diluent for a rebreather, or as the primary gas for an SCR, or as bailout for surface supply. Peter (Southwood) (talk): 19:21, 3 November 2011 (UTC)
 * You're right about how I'd see most of it. A pony cylinder in the UK (and most places I've dived around the world) is a cylinder which is not a primary cylinder, small enough to be portable if required. Its function is to act as an independent redundant air supply, nominally for use in emergencies only. The idea in the USA is that a diver can travel with their own pony and two regulators, but rent the primary cylinder as part of their dive package. It's not unknown for divers to fly with a pony cylinder in their checked baggage (with the valve removed during the flight). Now, I've seen a 6 or 7 litre cylinder used as a primary cylinder for shallow dives or for cleaning the underside of a boat, but in those cases it's never referred to as a pony. A similarly small cylinder filled with 100% O2 may be used to hold deco gas for the final stop(s) in a heavy deco dive, but again, it's not a pony (it's a stage) because the plan involves using it. The whole point of the pony is that it's not expected to be used, and I think that is the fundamental distinction. Here, it's a normal cylinder, with normal fittings for a regulator (A-clamp or DIN), almost certainly around 3-litre or 6-litre in size, whose purpose is bailout. So Spare Air isn't a pony because it has an integrated regulator, and larger cylinders are normally half of a twin set, which is a different way of providing redundancy. Does that give you a clearer of picture of the usage that I'd be accustomed to? --RexxS (talk) 01:46, 4 November 2011 (UTC)
 * Yes, that seems entirely compatible with how I see it. The marketing of harnesses using a pony bottle as a primary is a bit of a red herring, as by your and my definitions it would not be a pony when used that way. I think we should get this clarification into the article. Cheers, Peter (Southwood) (talk): 17:18, 4 November 2011 (UTC)

Octopus Regulators
The critique of octopus regulators states: “a failure of the first stage regulator or the exhaustion of the gas supply from the primary tank makes this solution inferior to a totally redundant breathing gas system such as a pony bottle”.

Inferior for whom?

Octopus regulators are primarily intended for supplying breathing gas to other divers - not oneself. And a pony bottle’s first stage regulator is just as likely to fail, as a main tank’s is.

It’s obvious to qualified divers, but I suggest spelling this out in more detail for the benefit of non-divers. I suggest replacing “Because of this… such as a pony bottle.” with something along the following lines:

“Octopus regulators are primarily intended for supplying breathing gas to other divers. For example, an octopus regulator carried by diver George, could be supplied to diver Mary in an emergency. But this would leave Mary dependent on George for the ascent back to the surface. If Mary carried a pony bottle, she could ascend independently. George could also use his own octopus regulator in the event of a failure of his other (main) second-stage regulator. However, a failure of George’s first-stage regulator, or the exhaustion of the gas supply from his primary tank, will render George’s octopus regulator unusable to everyone.” 06:22, 13 July 2022 (UTC) TC — Preceding unsigned comment added by 1.124.110.77 (talk)