Info Are Pony Bottles Dangerous?

[Bloody Marvelous]

I don't get the practice of pony bottles.

You're carrying an extra cylinder of gas that you have no plans of using. If you've got a 12 liter cylinder and a 7 liter pony, you're better off with 10 liter doubles.

If you're switching to Nitrox, you need to bleed down your pony and have it refilled. On doubles you'll have the same gas in both cylinders.

If you want to dive with multiple gases, you should have stage cylinders.

Doubles can provide full redundancy, and you don't need to add a 3rd second stage.

You can't accidentally have your redundant air supply turned off on doubles. If you do, you'll notice quickly that you're breathing down your cylinders a lot faster than expected, or if you have an SPG on one post and a transmitter on the other, you'll notice that you're only breathing down one cylinder.

I can't see any benefit to having a pony bottle over having backmounted manifolded twins, stage cylinders, or sidemount.

 

[FishWatcher747]

I can't see any benefit to having a pony bottle over having backmounted manifolded twins, stage cylinders, or sidemount.

1. Weight

 

[Bloody Marvelous]

1. Weight

Are a main cylinder + pony that much lighter than doubles with similar capacity?

 

[FishWatcher747]

Are a main cylinder + pony that much lighter than doubles with similar capacity?

I can't fly with mini doubles. I can fly with a 19 cu ft , 3L pony

 

[Marie13]

I don't get the practice of pony bottles.

You're carrying an extra cylinder of gas that you have no plans of using. If you've got a 12 liter cylinder and a 7 liter pony, you're better off with 10 liter doubles.

If you're switching to Nitrox, you need to bleed down your pony and have it refilled. On doubles you'll have the same gas in both cylinders.

If you want to dive with multiple gases, you should have stage cylinders.

Doubles can provide full redundancy, and you don't need to add a 3rd second stage.

You can't accidentally have your redundant air supply turned off on doubles. If you do, you'll notice quickly that you're breathing down your cylinders a lot faster than expected, or if you have an SPG on one post and a transmitter on the other, you'll notice that you're only breathing down one cylinder.

I can't see any benefit to having a pony bottle over having backmounted manifolded twins, stage cylinders, or sidemount.

Recreational divers on the Great Lakes will commonly carry a pony for deeper dives. Note they are recreational divers with single tanks. They maybe do a few charters a year. Do warm water trips, too, plus other diving such as quarries and inland lakes. Why should these divers who have no interest in tech diving go to the expense of setting themselves up with doubles or sidemount for a few dives a year? A pony is a lot cheaper and a lot lighter to carry than a set of doubles.

I used to be one of these single tank divers slinging a pony - 40cft in my case.

And there’s no need to bother with nitrox in your pony. Air only.

 

[Gandalf-the-Diver]

I've always viewed pony bottles as equipment focused on solving skills problems.

You should always plan your dives, plan gas consumption, and practice emergency drills.

If you're a rec diver, you must dive with a buddy who will be your first source of assistance shall you end up running out in emergency (e.g., a critical first stage failure). A pony bottle on a rec dive may give you a false sense of security or let you cut corners.

If you're a tech diver, you probably have doubles/sidemount/ccr and know how to stage, so the pony is not useful.

A pony bottle, is not intended to solve skills problems. They can however, do that by the simply being available when you need it; in that case, usually due to diver error. A pony bottle, is NEVER included in one's dive planning.
A rec diver, does not always have to dive with a buddy; it's called Solo or Self Reliant certification. A self reliant dive buddy, makes the best buddy. I have been slinging a pony bottle, since my 1st dive as a cert OW diver. I even slung it during my AOW course. 1st pony was a 13cu Catalina; sellers regret for selling it when I got a 30cu Catalina I know, when I am at 130', my 30cu pony, when full, will bring me safely to the surface. I also knew, my 13cu pony, if I was below 60', would get me to a buddy, not the surface. Either way, it was only to be used, during a primary gear failure, and never used to extend a dive.

 

[grantmac]

I can't fly with mini doubles. I can fly with a 19 cu ft , 3L pony

Even easier to fly with sidemount gear.

 

[SlugLife]

I don't get the practice of pony bottles.

It only matters if it works for that diver and the dive in question.

I'll explain my own benefit and reasoning, which of course applies to me and my dives. Sometimes I do (a) regular sidemount, sometimes I (b) replace one of the tanks with a pony bottle.

Regular Sidemount

Regular sidemount is great for deeper and longer dives. I have redundancy, but I also have a lot more gas. I can use "normal" sized bottles, which are easier to find on the used market, and even rentals tanks. I can even use the same 2 bottles to do multiple dives, sometimes 2, 3, or even 4 dives on a single pair.

Pony
The pony bottle, which is effectively unused outside of practice and emergencies is obviously primarily there as a kind of life "insurance." Yes, it's in my way, yes, it's ideally never used, yes it's something extra to carry. But the advantage of something like a 19cu pony over a 40cu "dive extender" is that the pony is always (nearly) full, always available, and it's relatively small, light, and minimal bulk. I know exactly what the limits of it's redundancy are for me. The pony bottle (compared to sidemount or doubles) is far less weight, especially on the surface, whether that's on the boat, up-or-down ladders, stairs, or even what I have to drag to-and-from my car.

A lot of my dives are relatively shallow, off my friends boat, and at places party boats like to hang out .... which means LOTS of waves. Climbing up a boat ladder with 2 full sized tanks, if I'm not careful, means a sore back for a couple days. Why take my full sidemount tanks, deal with the extra weight and hassle, when I can often do an hour dive on half an 80cu tank.

you're better off with 10 liter doubles.

If I had an unlimited budget, I'd probably run sidemount 2x 50cu. The problems are (a) I'd have to buy the tanks new, because I never see that size used, and (b) it would double the cost of fills, because around here they charge by the tank, no matter the size of the tank, and (c) I live a long way from the nearest dive shop, so I'd need multiple sets of mini doubles, or my own compressor.

 

[Angelo Farina]

A pony is an "add on" to normal equipment, to be added just when needed.
I own a pony, but I used it very rarely, and only a lot of years ago, for "demanding" dives.
It was added without modifying my main tank, which was either a 9+9 liters twin at 200 bar or a 15-liters single at 232 bars. In both cases with two separate valves, two independent regs and reserve, which is already a decently-redundant setup.
But when diving with deco and very deep (more than 50m) or in deep caverns, an additional pony (3 liters) gave me some backup in case of failures or misplanning.
I never had to use it, indeed. So perhaps it is just a psychological thing, making your more relaxed and confident.

 

[34109411]

I don't get the practice of pony bottles.

You're carrying an extra cylinder of gas that you have no plans of using. If you've got a 12 liter cylinder and a 7 liter pony, you're better off with 10 liter doubles.

If you're switching to Nitrox, you need to bleed down your pony and have it refilled. On doubles you'll have the same gas in both cylinders.

If you want to dive with multiple gases, you should have stage cylinders.

Doubles can provide full redundancy, and you don't need to add a 3rd second stage.

You can't accidentally have your redundant air supply turned off on doubles. If you do, you'll notice quickly that you're breathing down your cylinders a lot faster than expected, or if you have an SPG on one post and a transmitter on the other, you'll notice that you're only breathing down one cylinder.

I can't see any benefit to having a pony bottle over having backmounted manifolded twins, stage cylinders, or sidemount.

double are for technical diving and require a technical training. I don't need double for the recreational diving that i do. I carry a pony bottle for redundancy. i don't do wreck i don't do cave or deep dive or deco dive. Why should i use double ?