Is there a valid reason for a pony bottle

[saxman242]

And they are only my rules because of the way my friend uses his pony. He would stay on the bottom until he was low on air, switch to his pony for his ascent, suck it dry, then switch back to his primary and suck it dry. I don't allow him to use his pony on my boat any longer because I don't want him thinking he has a security blanket in case he screws up. I'd prefer he dives the way Merry and I do. I didn't say others can't use ponies. My boat is only big enough for three divers.

That sounds like the use of the pony is just the symptom of a mindset problem. Getting rid of the pony doesn't get rid of the problem, just the manifestation. The concern seems to be him not properly planning a dive and sucking his reserve supply dry. Does it really matter if he keeps his air in one tank or two? All pony discussions aside, I would think the approach to take here would be to just stop inviting him.

 

[MaxBottomtime]

Why dont you steer him to 120's or doubles then?

He's about 5'3" and uses a 130.

 

[CWK]

In parts of the world that I dive regularly, there is legislation that compells divers to carry an alternative air source. I carry a pony to satisfy this legal requirement. Most other divers carry an octopus to satisfy this legal requirement. To me, an octopus is not fit for purpose as an alternative air source. The elephant in the room is the octopus.

Would a skydiver dive with a reserve chute that can only be donated to another sky diver whose main chute fails to open?

 

[flyboy08]

In parts of the world that I dive regularly, there is legislation that compells divers to carry an alternative air source. I carry a pony to satisfy this legal requirement. Most other divers carry an octopus to satisfy this legal requirement. To me, an octopus is not fit for purpose as an alternative air source. The elephant in the room is the octopus.

Would a skydiver dive with a reserve chute that can only be donated to another sky diver whose main chute fails to open?

So true! If you blow the first stage O Ring, both of your regs are rendered useless....reach for the Pony and if that one blows too...well, it was just meant to be a bad day! Odds are in your favor though "

 

[Gareth J]

why are aluminum stages much better than steel stages? and would the same reason apply to pony bottles? Reason i ask im thinking of buying a steel 22cf pony.

thanks

I know a couple of other have answered, but I will answer as well.

Generally, an aluminium stage is closer to neutral than a steel. So carrying steel stages means you are generally over weight. (The reasons I had to start using my wing for buoyancy).
When you remove the stage and either clip it to a line, or hand it off to another diver, it immediately changes your buoyancy, i.e you suddenly go positive, and they suddenly go negative. On OC you have the advantage of your lung volume to help compensate.
When I switched to CCR it became very difficult to manage handing off stages during decompression stops. So on CCR it's really very foolish to use steel stages, and not that bright on OC.

An anecdote.
I did a trip to the South China Seas, all the cylinders where aluminium. As a group, we where so used to steel cylinders and stages, that we added 2kg weights to the tails to make them sit down in the water. As we progressed through the week we took the 2kg weights off. What we learnt, is that with an empty aluminium stage, you can push it back under your arm and let the tail of the cylinder float up, which is a lot more comfortable, than having the cylinder slapping in to your side.
P.S. My other lesson from that trip is that the white dust that corroded aluminium creates is really not good in a manifold assembly!

 

[markmud]

He's about 5'3" and uses a 130.

Hi Max,

I think you just made a statement against self interest. 5' 3" and sucks a 130 dry?

"Houston, we have a problem."

Many others have opined on this thread that your buddy's pony is not the problem. You have changed their opinions to a conclusive fact.

Don't fix the symptom, fix the root problem.

You do have a nice boat and I enjoy reading your posts!

markm

 

[NAUI Wowie]

plan your dive, dive your plan...it works every time until it doesn't!

Im gonna use this line at my LDS this week when I bring up still wanting a pony. They do not likey.....

 

[MaxBottomtime]

Hi Max,

I think you just made a statement against self interest. 5' 3" and sucks a 130 dry?

"Houston, we have a problem."

Many others have opined on this thread that your buddy's pony is not the problem. You have changed their opinions to a conclusive fact.

Don't fix the symptom, fix the root problem.

You do have a nice boat and I enjoy reading your posts!

markm

He wants every dive to be two hours or close to it. He was using his pony to extend dives. I prohibited his pony and said he must surface with at least 200psi in his tank. He gets in the water before we do and is often down for ten to fifteen minutes after we surface. That works for us as it gives us space on the deck to rinse off and get out of our drysuits before he comes up. He doesn't need to run his tanks dry just to get a few more photos. I'm trying to train him to be more careful. He dives with two computers, each telling him his remaining air as well as remaining bottom time based on his depth and pressure. There is no reason for him, or anyone to purposely run a tank dry underwater.

 

[Colliam7]

For most of the dive I've got redundancy of two separate cylinders.

Hmm. I wonder if this - 'for most of the dive' - is an example of what is referred to as a 'slippery slope'.

 

[MichaelMc]

I think anyone coming along later to read about redundant air systems will have the point.

There is a thread that described how you could have stage (bottom) air, deco air, and pony (redundant) air all in the same bottle. You just have to know to leave the pony air alone.

Good luck with your friend, they are using a stage bottle that they told you is a pony bottle.

Good luck.