All About Pony Bottles

[divestoclimb]

I've been diving this pony for quite a while leaving the valve on for days at a time. Never once had any problems.

I had a problem with that once, so it can happen. I left my doubles rig outside in a truck overnight and by the morning I had lost 1000 psi because the valves were open. If gear gets piled on top of the pony rig, the purge can get pressed on the regulator and drain the tank. Also if it's cold outside the second stage can crack open. Since you should be checking the pressure in that tank and checking that the regulator breathes OK before each dive anyway, you might as well close the valve when you're out of the water or done for the day to prevent this.

As for the dive with the pony open vs. closed... I'll leave that to someone with an actual story to tell.

 

[shoredivr]

I've heard this before and just don't buy it. It's always that mythical "something" that bothers me. "It could get caught on "something" and go into freeflow and you'd never know it." Yes, I would know it. I can hear a leaky O-ring so I'm quite sure I'd hear a 2nd freeflowing. Not to mention the mass of bubbles all around me. I've been diving this pony for quite a while leaving the valve on for days at a time. Never once had any problems.

-Charles

Well, whether you buy it or not, it was taught in my deco course and makes sense to me . Conserve gas you need for deco; or for NDL cold water or deep diving, conserve gas you need for redundancy.

I don't see how difficult it is to open or close a tank valve, especially one that's hanging off the left side of my harness. Is that your concern?

Of course, it may be harder to do so on a back mounted pony tank, depending on configuration (pony tank valve up or down). Which brings up the concept that you can see which regulator you're using on a side-slung tank. There are numbers of accounts of people grabbing the back-mounted pony reg at the beginning of the dive thinking it was their primary and breathing the pony down...confusion results, etc. etc.

As an interesting aside about hearing the reg freeflow, String posted this over in the Accidents forum. Note bolded part. So, obviously freeflows - while perhaps not occurring for you - are happening and causing problems.

BSACs UK incident report was published this week.
Of the DCI incidents, 38 of them involved rapid ascents.
In the ascent category, 22% were weighting or weight related problems
17% regulator freeflows (!!!!!!!)
15% poor buoyancy control
15% Delayed SMB problems

Its worrying that a freeflow is causing people to have rapid ascents, also worrying that the DSMB problem hasn't been solved.

Full report here with individual case details:
http://www.bsac.com/core/core_picker/download.asp?id=14699&filetitle=Diving+Incident+Report+2008

 

[seaducer]

Hey everyone, I'm a relatively new diver looking to purchase some equipment in the near future. Although I always dive with a buddy, I would prefer to be as self-reliant as possible, so am thinking a pony bottle would be a good investment. I've tried to research them but have been incredibly confused by conflicting information, so have a ton of questions:

Good questions. I am sure you got some good info, I will tell you what decisions I made, and why.

1.) Does a pony bottle replace the need for a backup second stage from your main tank?

I chose to keep my backgas regulator intact. If you choose to mount your pony on the main tank you may want to use that as the secodnary. To many hoses to contend with get confusing and is harder to streamline.

2.) I see a lot of stuff about pony bottles being attached to a BCD, or turning them on only when needed, and all this stuff. I always thought that a pony bottle was attached to a tank and turned on for the entire dive? Are they just different options, or how do people usually use them?

I chose to sling my pony. A pony is small, and a slight leak can leave you dry when you need the gas. If the pony is slung you can see it leaking and shut it down. Some people prefer to leave it shut down, but I feel this is a bad idea. In an emergency you may forget, take a breath or two, then go OOA again and this time you panic and bolt for the surface. Additionaly I enjoy the option to donate my pony to an OOA diver, and hand him the whole thing, thus reducing my exposure to their potential panic. Also, riding the bottle on my stomach means it is below my center of gravity, or bouyancy while diving. This means it effect my trim far less than if it were on my back, to one side of the tank, pushing me off balance.
Lastly I bungy the second stage to the bottle so it is out of the way and impossible to confuse with anything else, and yes I have a button gauge.

3.) When purchasing, what size would be preferable (assuming the possibility of deep diving in the future - up to 130 feet)? Also, is it generally best to buy a pre-configured system or just buy a tank and regulator yourself? Are they generally easy to switch between tanks (I plan to continue renting my main tanks)?

If deep diving is in your future, a 40 makes sense, as this way you can use it as a stage bottle for deco later in your career. If you intend to stay recreational then I would suggest figuring out how much gas you need to get safely up from the deepest you intend to dive and buy at least that size, if not one bigger to account for anxiety. I purchased a 19cf, it is small enough to disappear, large enough to get me from 100 feet to the surface.

4.) Would you generally fill a pony bottle with air or nitrox? Do pony bottles need a PSI gage to tell how much air is remaining?

This for me is a variable. Right now it is filled with air, however if I am going to be using nitrox on a hard bottom I may choose to fill it with a mix that is within the MOD for the max depth I can achieve. I don't see me ever doing this but it is an option. Anothe option is to fill with a high % mix, but then you lose the deep water bailout option and now you have a "deco" bottle in case you un close to an NDL. In this case I would shut the pony down at depth so I can't pass it off accidentaly. Again I don't see me doing this, but it is an option.

5.) Any recommendations or at least give a rough idea of how much I should be planning to spend?

I spent about about 150 on the bottle, I bought a new setup for my main tank and moved the old one to pony duty. I would say deals could be had for 250 to 350, but this is speculation.


Maybe some of this is new info, but at least if it isn't perhaps the ideas reinforce what other people said and help you make your decisions...good luck

 

[Coldwater_Canuck]

Well hearing similar info in a topic like this is never a bad thing as it reinforces what everyone one else said.

So I guess what I'll do is I'll "try" slinging. This seems like the cheaper option since you can make a sling yourself for around $20 apparantly. If I don't like it, I can always just spend the money on a tank mount kit. I also plan to use a bungee to keep it in one nice package. I'm still skeptical, but if this many divers don't find it annoying, you must all be on to something

I also tend to agree with you about leaving it turned on. I guess there's some risk either way, but I'd notice a freeflow, and as long as I occasionally check the gauge, I could notice a small leak.

For size, I'm leaning towards 30, but not yet sold on it.

 

[DaleC]

Hi CC.
I side sling mine so I can see if it is leaking air, work the valve, read the button SPG and hand it off to another diver should the need arise. It sits very nicely, doesn't affect trim and I don't notice it is there when diving. Some people do backmount, and there are brackets made so you can hand off a back mounted pony (in theory) but I just did a pool session with someone who is side slinging theirs now because the back mounting bracket was too hard to manipulate in practice (something to test out first if you go the back mount route). Here's a link to another thread where I posted a pic of how mine is mounted on page one
(http://www.scubaboard.com/forums/advanced-scuba-discussions/258394-pony-bottle-mounting-options.html)


I debated the size of pony to use quite a bit. I am not rich and have lots of gear to aquire so I only wanted to buy one bottle. Initially I was thinking smaller as I only wanted it for emergency gas in a REC OW situation but after a lot of thinking and discussions I went with a 30cuft. bottle. This gives a good amount of gas to work out problems UW if they occur (which might require more than a straight forward bolt to the surface) and also it is a decent size to later be used as a small stage or deco bottle should one choose to go deeper/tech.

I dive with my valve open. I do this primarily because it is a rec pony, used in an emergency for an alternate air supply. If I or another diver is OOA, pulling a dead reg may be that one task too many. My theory is that many people who dive with theirs valve closed may come from a tech perspective and see the pony as another form of deco bottle. Deco bottles are dived valve closed to avoid the accidental loss of gas needed to meet a deco obligation. They are not (primarily) thought of as an emergency alternate air supply.
IMO
The risk a deco bottle alleviates is deco obligation so the valve is closed to preserve the gas. Losing gas is more of a risk than not having immediate access.

The risk a pony alleviates is loss of primary air supply so the valve is open to provide immediate relief. The risk of losing some gas is not the same.
Again, just my 2CW. I certainly could be wrong about other peoples motivation.

Lastly, I am probably the last guy to say this but don't assume that diving with a pony is no problem. In the grand scheme of things it is not a complicated gear configuration but for a new diver it could present some significant task loading.

Hope some of this helps,
Dale.

 

[farsidefan1]

Weight problems have kept me from using a pony. It seems like all the cool places I want to dive involve severe weight restrictions. between 40 to 50 lbs for checked baggage (If I take my split fins my gear comes in at 47 lbs - they add 2 lbs) and as little as 17 lbs for the carryon. That means 17 lbs for all my nondive stuff. Actually on a liveaboard this works. I mean, what do you need? but geez. It's those little jump planes that really kill you on weight limits. I appreciate the info on this thread. If I get one I think I would get the 13 or 19 as I dive tropical and avoid serious overhead environments. It would just be in case of catastrophic equipment failure or to help someone else. I have done a few solo dives without any backup air but that was just stupid for me at the time. Now I'm married and have a dive buddy I would just like to have enough air to get safely to the surface.

 

[Coldwater_Canuck]

DaleC, that's a nice setup you've got and what I'm going to try aiming for. I will also probably end up going with the 30cf. You're point on the tek setup for leaving it closed makes sense, and in my (granted, uninformed) opinion, the risk of a leak is much less than the risk of when someone really needs it forgetting to turn it on.

And I don't assume it's necessarily "no problem", but I will need to get used to it eventually, and I think the added safety will be worth any initial pain.

 

[Tortuga68]

the risk of a leak is much less than the risk of when someone really needs it forgetting to turn it on

Ideally you should be purging the reg first to ensure it's working before swapping anyone onto it

 

[Coldwater_Canuck]

Ideally you should be purging the reg first to ensure it's working before swapping anyone onto it

Ideally, yes. And in a drill turning it on and purging is not exactly a difficult task. However, I cannot say how I will act in a true out of air emergency, and I have a feeling no matter how well I prepare my instinct may just be grab the reg and start breathing. To me, the small chance of a leak that I would in all liklihood detect (plus the fact I'm not going solo, so there is still another backup plan in my buddy) seems better than the risk of forgetting to turn the bottle on in an emergency, breathing from the reg, and at that point when not having any air come out, panicking or who knows what?

I think it's one of those situations where you need to balance the odds, and my instinct (and that's all it is, I have no stats or anything concrete to back me up) is leaving it turned on would be the safest thing.

That's the difficult thing with emergencies, you're never sure how you will be thinking. So far the only time I had a real "oh crap" moment was when my reg fell out of my mouth at 60 feet. Fortunately in this case by instinct i did the right thing and sweeped my arm and got it, but there were a couple seconds there where my mind was definately panicking a little and I know I wasn't in the best state of mind to be thinking completely straight.

 

[charlesml3]

I left my doubles rig outside in a truck overnight and by the morning I had lost 1000 psi because the valves were open.

I would consider this a GOOD thing. You found out you had a leak in your system on land where you could do something about it rather than on the boat or even worse, at 70 feet.

If gear gets piled on top of the pony rig, the purge can get pressed on the regulator and drain the tank.

Properly stow your gear. I do. Turning the valves off because you can't be bothered with stowing your gear properly is a pretty poor excuse.

We all check our tank pressure before we leave the dock. Clearly this practice should extend to the pony tank as well.

it was taught in my deco course and makes sense to me

Yea, the DIR crowd always goes on about this. "Leave the valve off and "feather" it from time to time during the dive." Why not leave it on and not have to worry about it? It's not about whether not it's difficult to open the valve. Leaving it open is just one less thing I have to do. Also, my pony is not there just for me. During the briefing if there's anyone there who hasn't dove with me I go through the same routine. I show them where my pony 2nd is clipped and instruct them if they need it to just grab it. I have no problem whatsoever with another diver grabbing my pony 2nd if they get into trouble. With the valve on, we're all good to go.

In all honesty, I can reach the valve. My pony is mounted valve down and I use the Zeagle Razor. I can reach down with my right hand and go right to it without looking. During the descent, I reach back and make sure again that the valve is fully opened.

17% regulator freeflows (!!!!!!!)

I know that freeflows cause problems. Of course they would. I'm pretty sure that the odds of my primary, my octopus and my pony 2nd ALL experiencing simultaneous freeflows is ridiculously remote.

-Charles