Pony bottle mounting options?

[J.R.]

... question to those who use ponys...

The local LDS is looking at having a visiting instructor come in this winter sometime and doing a ice diving class for a number of us. I've been doing some reading and grasp the concept of using a pony and separate reg system... but, with regard to mounting it...
is there any problem with mounting it upside down that anybody knows about?

We've got a spiffy little clip/strap arrangement that holds the pony to the AL80... theory goes that if a handoff is needed that the strap buckle could be released and, if the pony was valve down... the pony could be easily dropped.

Anybody see a problem with this in concept or practice???

 

[hobodiver]

Actually, now that I think about it further, I can't think of any reason why I'd want to hand off my alternate air source. If I need it, or my buddy needs it, dive is over and we're heading up together - one less reason for me to sling it

What if your dive buddy is seriously entangled or otherwise trapped? With a sling configuration, you can hand off your pony, and then go get help/more air. While theoretically possible with a back mounted pony bottle, not all connectors are easily releasable.

 

[String]

If you must back mount it upside down is probably best- then at least you can reach the valve pretty easily. If you're anywhere near horizontal in the water the clamp should be fine. I dont think you'd ever want to hand off a back mounted tank anyway. Its fairly common to see upside down back mount here. Mostly from people with BCs that wont easily accommodate sing sling.

 

[Aardvark]

OK. Reasons i dont like back mounting:

(i) Some people find it hard or impossible to reach the valve (its harder than a twinset)
(ii) If it leaks you maybe completely unaware. Or if it freeflows unable to stop it
(iii) the balance issue
(iv) If you dont have a proper SPG you will be unable to see it on a dive
(v) Hose chaos - people have died getting hoses confused and incidents are fairly common every year. In a stressed situation its not always easy to work out what hose comes from where.

Back mounting is more likley to get tangled, can more easily leak out if you leave it on, is harder to turn on if you leave it off (since it is behind you) and makes the rig heavier when exiting the water (a slung bottle can generally be passed up before exit) and lastly, if your scuba unit gets very tangled in a net or something, you won't generally be able to easily remove the pony bottle and swim up with it if it is back mounted.


String beat me to it, the possibility of confusing the pony and primary reg, when back mounted, is significant and HAS killed people.

A slung bottle is safer.

I use a back mounted pony because it is out of the way, but it does have some disadvantages.

Thank you, all good points:

My 40cuft pony is the same height as my 100cuft main (just slimmer). I can reach and manipulate both valves comfortably. I do always leave it on and have a full SPG attached, which I check as often as I check my primary. I always do a bubble check with a buddy at the start of a dive (I can at least insist on that before they swim away) and consider it very unlikely that my (completely independant) primary and emergency air supply will fail at the same time.

I hadn't considered the danger of confusing the primary reg and alternate reg as both will deliver air at any time and I'd notice the error the first time I checked SPGs (if my buddy hadn't pre-dive). More information on this would be appreciated. There is no "octopus" in my setup - the second stage from my pony is routed under my arm and up to right shoulder D ring - where an octopus would be on a single tank.

I don't do penetration dives of any sort and there is minimal risk of entanglement where I do dive. If I was tangled I can always doff my gear and sort it out - even if I need to resort to shears. I can see why a slung pony would be an advantage in this situation. It is a little heavier climbing up the boat ladder but from a small boat, even in a slight swell, I don't want to be passing cylinders back and forth where I could get hit by a rolling boat.

I haven't noticed the adverse trim/balance; but then I may well be swimming in circles or unconciously compensating in other ways.

 

[Aardvark]

What if your dive buddy is seriously entangled or otherwise trapped? With a sling configuration, you can hand off your pony, and then go get help/more air. While theoretically possible with a back mounted pony bottle, not all connectors are easily releasable.

I don't do penetration dives of any sort and risk of entanglement where I dive is slim. In the situation you describe if going to get help was the best course of action then my shears would make very short work of the webbing securing the pony.

 

[DaleC]

Hi Marc, The Drings on my BC are useless as is. I had to add one on the hip and am in the process of cutting off the shoulder ones and replacing them with bent ones as you noted.

I don't know about Zeagles but I don't think a slung pony puts that much stress on a D ring. It hangs straight down on land and is only -2lbs in the water.

I don't notice it affecting my trim submerged but it throws me a little off kilter on the surface. Not really a problem as much as something to adjust to and It doesn't hamper the inflator hose. Also, one guy I know doesn't clip off the bottom snaplink but I often see the pony floating out away from his body like buzz lightyears wing. With both clipped off it stays parallel to the body.

Like some others, I was going to try backmounting but (because I solo) I don't like the idea of not being able to see whether it was leaking/free flowing etc...

I think a good reason to sling it on the left is so it doesn't interfer with the deployment/function of the primary/octo regulator hoses.

 

[hobodiver]

I don't do penetration dives of any sort and risk of entanglement where I dive is slim. In the situation you describe if going to get help was the best course of action then my shears would make very short work of the webbing securing the pony.

What if the pony clamp is metal? And how are you going to use your shears on a back mounted pony?

I don't do penetration dives either, but there are plenty of entanglement opportunities around here.

If you're comfortable with your configuration, then that's great. I just feel my sling mount offers a bit more flexibility, although at a slight bit of inconvenience (in the way a tiny smidgen).

 

[Aardvark]

What if the pony clamp is metal? And how are you going to use your shears on a back mounted pony?

I don't do penetration dives either, but there are plenty of entanglement opportunities around here.

If you're comfortable with your configuration, then that's great. I just feel my sling mount offers a bit more flexibility, although at a slight bit of inconvenience (in the way a tiny smidgen).

Glad you're happy with your rig. I'm not trying to convert anyone, just elicit opinions to help me think through my own diving and hope others do the same.

My pony is secured using a couple of cam straps, not metal. In the unlikely situation you describe I'd need to doff my rig, snip the pony free and hand it over if it wouldn't come free after releasing the cam locks. I'm struggling to think of an entrapment/entanglement scenario that would result in me "going for help", though.

 

[dumpsterDiver]

Thank you, all good points:

I hadn't considered the danger of confusing the primary reg and alternate reg as both will deliver air at any time and I'd notice the error the first time I checked SPGs (if my buddy hadn't pre-dive). More information on this would be appreciated. There is no "octopus" in my setup - the second stage from my pony is routed under my arm and up to right shoulder D ring - where an octopus would be on a single tank.

.

The problem scenario goes like this: The diver enters the water believing he is breathing from the main tank. However, he is confused and is using the pony instead. The pony tank runs dry quickly.

The diver is confused why his main tank has stopped working (especially when his guage says full) but spits out the reg, fumbles a little, and attempts to switch over to his pony reg. Of course this is the same reg he has breathed down to nothing, and after the "switch" he gets no air, but by now the the diver is totally confused, can't figure it out and drowns or shoots for the surface.

This mistake is pretty much impossible with a slung pony, because the reg is held attached to the pony with elastic bands and you can see what you are breathing...

 

[Aardvark]

The problem scenario goes like this: The diver enters the water believing he is breathing from the main tank. However, he is confused and is using the pony instead. The pony tank runs dry quickly.

The diver is confused why his main tank has stopped working (especially when his guage says full) but spits out the reg, fumbles a little, and attempts to switch over to his pony reg. Of course this is the same reg he has breathed down to nothing, and after the "switch" he gets no air, but by now the the diver is totally confused, can't figure it out and drowns or shoots for the surface.

This mistake is pretty much impossible with a slung pony, because the reg is held attached to the pony with elastic bands and you can see what you are breathing...

OK, so you gear up, put in the wrong reg, your buddy doesn't notice either pre-dive or on bubble stop, you don't monitor your air and go OOA, panic and try to breathe from the reg you just spat out rather than just grabbing "the other one".

I shouldn't be surprised that this happens.

That's a fair argument for slinging your pony. I'd also see this as a reason to have clearly readable SPGs on all your air sources and monitor them regularly and, if you're going to carry a pony, make sure it's a reasonable size. Though, given the amount of OOA incidents that occur, maybe that's too much to ask!