The Natural
Contributor
Standard practice is have a normal 2 reg set up on you back gas and then however you choose to sling or mount the pony have 1 reg.
Your opinion on configuring a pony
- Thread starter Jersey Diver
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lamont
Contributor
Things to consider:
- can you find the second stage for the pony quickly in an emergency?
- will you be able to notice a second stage free flow?
- will you be able to notice bubbles from your first stage?
- can you check the pressure in the pony bottle before and during the dive?
- will you be able to shutdown the first stage if the pony reg free-flows?
- will you be able to turn on the first stage if you jumped in the water with it turned off accidentally?
Generally a slung pony bottle solves all these problems. A butt mounted pony with an SPG on it, and positioned so that the valve can be reached at least fixes the more severe issues.
- can you find the second stage for the pony quickly in an emergency?
- will you be able to notice a second stage free flow?
- will you be able to notice bubbles from your first stage?
- can you check the pressure in the pony bottle before and during the dive?
- will you be able to shutdown the first stage if the pony reg free-flows?
- will you be able to turn on the first stage if you jumped in the water with it turned off accidentally?
Generally a slung pony bottle solves all these problems. A butt mounted pony with an SPG on it, and positioned so that the valve can be reached at least fixes the more severe issues.
JeffG:
I think Dandy Don has an interest in his buddy. He's got permanent notes written on his slate now asking his buddy not to disappear. I don't think you have any regard for him. I think he was insane to post his experience because it gets regurgitated in the guise of trying to help someone. I don't think the poster feels helped at all in the responses he's received so far - with the exception of Lamont's post.
JeffG
Contributor
You misread. You have to put both comments that I quoted together to understand my post (reg config and drained pony). It (my post) has absolutely nothing to do with DD, but feel free to believe whatever you wish.redhatmama:
OP
Jersey Diver
Guest
HEY, Thank you for all the replies, I realize that there is a 20 or so page thread on this, and i made it to page 5, but i do appreciate all the new posts. I must admit that at first i was only thinking of having a redundant air supply for myself. I didn't realize that i was leaving a buddy out of the picture. With that all said i still will use a pony for an emergency but i think it would be smart to also have an octo. It all is making sense, im glad i found this site. Going to dutch sounds like a great idea, since every piece of equipment is new & it will take some time getting familar with it all.
JeffG:
Ya think?
FWIW, I'm not making fun of anyone. Instead, I offer the link as a warning. The thread epitomizes everything that I don't like about pony bottles, especially back mounted pony bottles. It also demonstrates the consequences of poor gas management, training, planning and decision making. All of these are relevant to the question posted, particularly since the poster is a relatively new diver who will need to integrate the pony into his/her planning and protocols, and who may not have experience with the consequences of diving errors.
We now return to your regularly scheduled program.
In addition to mounting issues, another item to consider is when the pony will allow you to bail out of a problem. I'd recommend that you calculate whether you can ascend from various depths while making all required or recommended stops, at a safe rate. I'd also see how long you can stay at a particular depth while using the pony and still make a safe ascent. That way, you'll know whether you need to immediately bail out, or whether you can safely return to the line before ascending. You'll also know how deep you need to go in order to render the pony inadequate for the dive. I'd analyze this using a higher than usual SAC rate, because you may find yourself stressed and breathing harder than normal if you need to deploy a pony.
Once you have made your calculations, test it empirically by deploying the pony and verifying the accuracy of the calculations. In addition, I'd regularly practice ascents using it. The practice sessions should be done with enough back gas to safely ascend, so you can deal with any problems.
I suspect that you'll find that the AL30 will work in most recreational situations, but this information is still worth knowing.
I use a standard setup for my main tank, with a regulator and octo. My pony has a regulator that I bungee around my neck.
That way, if there is an emergency OOA situation for another diver, he can look for the octo where it would normally be. But if he grabs my second stage, I have my pony reg right there on my neck.
And if I have a catastrophic situation with my main tank, my pony reg is very handy. Also, on every dive, I do at least one practice change over.
As a disclaimer, I have only recently begun diving with a pony bottle, so this is a preliminary set up.
Jeff
That way, if there is an emergency OOA situation for another diver, he can look for the octo where it would normally be. But if he grabs my second stage, I have my pony reg right there on my neck.
And if I have a catastrophic situation with my main tank, my pony reg is very handy. Also, on every dive, I do at least one practice change over.
As a disclaimer, I have only recently begun diving with a pony bottle, so this is a preliminary set up.
Jeff
30, my opinion only (see my sig line), is pretty healthy sized. If you're comfortable with it, make it a regular part of your gear configuration, practice using it, great. People yanked my chain slightly for bringing a pony on vacation -- I'd much rather take chiding than go non-standard, and absolutely believe in my redundant air supply as a normal item, something I don't want to have to think about using when the dung hits the fan.
I use a tank mount (QuickDraw), like it, though appreciate that a sling mount also works well. Please note that you may need to adjust your weight distribution to maintain trim -- the pony is likely to be a couple of pounds negatively buoyant, when full. Running the numbers, if I had an original "good" weight I would shift two pounds of it from the side with the pony to the side without it.
This keep-the-basic-weight-but-shift-two-pounds actually means that you would be carrying an "extra" 3 pounds, purposefully, when stuff is going well and you are not having to use the pony. If you are geared up, at your 15' safety stop with 500 psi in your AL80, you would then actually be -3 lb, not neutrally buoyant. The "why" of this is that the pony is bailout gas, so you assume that if you need it you have burned off your main tank (1 lb of buoyancy change when the tank goes empty compared to at 500 psi) and are sucking down the pony (2 pounds of buoyancy change).
(The above is just math, weight of air, no magic, attempting to keep clean trim when things are going well, but enough weight to handle a safety stop when things have gone wrong and you need that pony because a bad whoops has wiped out your primary tank. If anyone sees logic flaws, please comment, but I believe the underlying concepts are generally appropriate given that a person is carrying a pony -- maintain trim and carry the weight to compensate for loss of gas.)
As always, your mileage may vary -- this is just my logic process, what I personally do.
Good luck!
I use a tank mount (QuickDraw), like it, though appreciate that a sling mount also works well. Please note that you may need to adjust your weight distribution to maintain trim -- the pony is likely to be a couple of pounds negatively buoyant, when full. Running the numbers, if I had an original "good" weight I would shift two pounds of it from the side with the pony to the side without it.
This keep-the-basic-weight-but-shift-two-pounds actually means that you would be carrying an "extra" 3 pounds, purposefully, when stuff is going well and you are not having to use the pony. If you are geared up, at your 15' safety stop with 500 psi in your AL80, you would then actually be -3 lb, not neutrally buoyant. The "why" of this is that the pony is bailout gas, so you assume that if you need it you have burned off your main tank (1 lb of buoyancy change when the tank goes empty compared to at 500 psi) and are sucking down the pony (2 pounds of buoyancy change).
(The above is just math, weight of air, no magic, attempting to keep clean trim when things are going well, but enough weight to handle a safety stop when things have gone wrong and you need that pony because a bad whoops has wiped out your primary tank. If anyone sees logic flaws, please comment, but I believe the underlying concepts are generally appropriate given that a person is carrying a pony -- maintain trim and carry the weight to compensate for loss of gas.)
As always, your mileage may vary -- this is just my logic process, what I personally do.
Good luck!
Daryl Morse
Contributor
Jeff, I think you're being presumptuous. Where did you get the idea that he was inviting you to go diving? LOL!JeffG:
To answer the original question, I occasionally dive with an AL40 configured as sling bottle. I recommend that configuration because everything is visible and accessible. I started diving with that configuration as part of taking the ANDI CSU course, which covers various practical aspects of diving with two mixtures of nitrox. In the course, we covered air sharing with the backgas and sling bottle regs, gas switching and donating the entire bottle to the buddy, among other things. Excellent course if that's what you're looking for.
Northeastwrecks:
The way I see it is that Don is an active member and seems like a nice guy. A lot of people here know him, have dived with him and like him. Has anyone greeted more new members than Don? You can offer the information without the details of that particular incident.
It also serves to discourage people from ever posting an incident or at least wiping your cookies and posting as a new user. That's what I would do.
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