Considering buying a pony/back-up tank.

[2airishuman]

I want to get a pony/back-up tank.

Good for you

There are numerous sizes and configurations. I just cannot seem to sort it out. Not sure best way to mount or carry. I want it to be a none complex issue if i need to use. Tank mount look good < But how easy is it to access??

There are no widely accepted best practices.

Tank mounted ponies pose potential safety problems. There have been fatalities when divers with that configuration make a mistake and breathe off the pony regulator when they think they are using the regulator for their main cylinder. The best practice for back-mounted pony cylinder, if you do decide to use one, is to connect the pony to a regulator that is bungeed under your chin, and then use an Air2 (or other integrated power inflator) as the backup regulator for your main cylinder.

I use a sling-mounted pony, that is, one carried exactly the same way as a stage bottle or deco bottle would be carried by a technical diver. Because the valve is visible and accessible, it is easier to determine for certain which regulator is which.

A LP30 seems sufficient.

Sizes of pony/bailout cylinders are a controversial subject on scubaboard. There are two schools of thought.

One school of thought is that, for recreational dives, the pony cylinder is a piece of emergency equipment intended to provide enough air for an immediate, controlled, direct ascent to the surface. People who use this approach may use cylinders as small as 9 cf, depending on the depth of the dive and other factors.

The other school of thought is that a pony cylinder should provide sufficient gas for some amount of problem identification/resolution at depth, usually 30-60 seconds, followed by a controlled ascent at standard rates, a safety stop, ascent to the surface, and some amount of surface reserve. People who use this approach typically determine that a 30 cf cylinder is the minimum size that will meet their requirements, and often end up purchasing a 40 cf cylinder because of trim and buoyancy considerations and the fact that 40cf cylinders are widely used as stage and deco cylinders in technical diving.

There is wide consensus that the 1.5 and 3.0 cf cylinders are too small.

My LDS told me I needed a Technical Cert. to use double tanks.

Some LDS feel this way, most do not. I dive doubles, and do not hold a technical cert.

 

[shurite7]

Seems like everyone who dives in the Great Lakes disagrees with that assessment. Probably because of the significantly heightened risk of free flow in cold water and thus the added comfort of having four independent sets of regulators for a buddy pair to rely on.

Up here we dive in cold mountain lakes and understand the risk of free flow. Therefore we practice skills with our buddy. In addition we all use regs that are good for diving in cold water, including under the ice..

I have seen plenty of people carrying around a pony bottle, deploy it once when they first get it, and then when something happens they rocket to the surface because they didn't want to practice; worse yet, they don't want to practice with the person whom they are diving with, something they. Therefore, the pony bottle and reg were a waste of money.

 

[JohnN]

My $0.02.

As others have highlighted, you should evaluate what function you would like the pony to fulfill and whether you ever plan on flying to a dive location. The later is important because I believe you should always dive with the same gear configuration. If you're diving at home with a pony, it should be traveling with you and an AL40 is just too big to fit into your luggage

If your pony is for a "poo-hits-the-fan" incident, an AL19 will give you sufficient air to do an orderly ascent from 100' (with a safety stop) even with a SAC of 1.0 cuft/min. And for travel, an AL19 will fit nicely into your luggage.

 

[KeithG]

I want to get a pony/back-up tank. I do dive with a partner, But I also like to be self sufficient. Better to depend on myself 1st. There are numerous sizes and configurations. I just cannot seem to sort it out. A LP30 seems sufficient. Not sure best way to mount or carry. I want it to be a none complex issue if i need to use. Tank mount look good < But how easy is it to access?? I like to carry redundant equipment (Like a Solo diver) to be safe.I am considering a Solo Diver and technical Diver cert. in the future. My LDS told me I needed a Technical Cert. to use double tanks. For the main fact the I usually travel with the (Internationally) wife and she does not dive.

What problem are you trying to solve? The gear you carry should directly address your current dive (unless you are a christmas tree diver...).

If you provide more details about the intended purpose then you should get more relevant advice (hence the popcorn response...)

 

[kelemvor]

I got a pony last summer and went with an AL13. Works fine, plenty of gas to get to the surface for an NDL single tank dive where I would carry it.

In a recent thread about pony mounting, someone clued me in that back mounted pony bottles have directly resulted in several deaths. I believe because of divers using the wrong regulator and running OOA but I'm not sure. Search for the other thread if your'e curious. The post listed several fatalities that were a direct result of the back-mounted pony. Sling them only.

I went smaller because I decided it would be less of a hassle to travel with and to use. That makes me more likely to actually carry and use the pony. It doesn't do any good if it's at home or in the car when I dive. Also, I made a transfill whip. I haven't had to use it (other than testing) but with such a small tank it shouldn't be a big deal to transfill if I'm traveling and the op doesn't want to fill my pony.

I don't bother with it on a deco dive because I'll already be on doubles, maybe also with an al40 deco bottle. I only use it for single tank NDL diving.

 

[tbone1004]

My understanding is that a 40 is way more than anyone diving recreationally would ever need, but the rationale is that it's far more useful if you do go tech and (for the same reason) is much more valuable if you ultimately decide to sell it.

correct. If slung they are also MUCH easier to deal with because of their buoyancy characteristics and length. They are about 2lbs less negative full than the smaller tanks so they disappear a lot easier and don't throw off your buoyancy quite as much. If you are mounting them to the main tank then it doesn't really matter, but it always makes me giggle when I see people slinging al19's because of the trim/length.

 

[uncfnp]

I have seen plenty of people carrying around a pony bottle, deploy it once when they first get it, and then when something happens they rocket to the surface because they didn't want to practice; worse yet, they don't want to practice with the person whom they are diving with, something they. Therefore, the pony bottle and reg were a waste of money.

OMG! Because you “personally” saw someone use a tool incorrectly that tool is useless and a waste of money? How do you respond to someone that uses this tool and uses it correctly? Did I waste my money? Yes, pony bottle threads are still the one area on SB where I can be baited.

To the op, I suggest you concentrate on the replies from divers that actually carry pony bottles.

 

[shurite7]

OMG! Because you “personally” saw someone use a tool incorrectly that tool is useless and a waste of money? How do you respond to someone that uses this tool and uses it correctly? Did I waste my money? Yes, pony bottle threads are still the one area on SB where I can be baited.

Years ago I got caught up in the pony bottle craze during my trips to the Caribbean. I bought an AL13 along with a reg and played with it, for a while. After gaining more experience and training I learned there were smarter options, such as communicating with my buddy, who ever it was, and doing a little bit of practicing before the dive. In short, I learned the pony wasn't needed in normal recreational diving.

Currently, I use a pony bottle (slung AL40) when solo diving and in special occasions, such as ice diving or diving in a missile silo. I also use an AL40 for deco. Furthermore, I carry a pony on my back for PSD or when diving in a swift river where buddy separation is not uncommon. This means I am quite knowledgeable and experienced on the topic. Quite often the pony bottle in recreational diving is used for a problem that doesn't exist. Developing one's skills, including buddy skills, and expanding his or hers knowledge is much smarter than shucking out the money for a piece of equipment that is claimed make a dive "safer".

In the end I am not going to demand someone not carry one. If they do, I encourage them to practice with it. Sadly, many divers don't want to take the time to practice any of the basic skills they learned in BOW, let alone deploying a pony bottle.

So, instead of bulking, why not stop and think things through. Granted, a diver can do whatever or buy whatever they want. Following a craze doesn't mean it is a good idea. The bottom line is a diver needs to be honest with him/herself before jumping into something. Are they willing to learn how to use the equipment and are they willing to continue practicing with it? Most recreational divers do not fall into the category or practicing. Be the thinking diver rather than one who wants to buy equipment to make a dive "safer".

 

[ontdiver]

Our Cornwall, Ontario club dives the St Lawrence River and due to viz and current, buddies routinely become solo divers for the long drift dives. Those of us not diving doubles generally carry a 40 for this reason.

 

[uncfnp]

shurite7 I pretty much agree with most of what you said and it is overkill for a large number of recreational divers that choose to dive buddy. But we all know that the buddy system, even in pairs that practice it right, can go sideways. It just takes a blink of the eye. And we have examples of that in the A &I thread.

I do not claim that pony bottles make any diver safer. A diver makes the dive safer and a pony bottle is just another tool.