Pony/Redundant Set-up

[drbill]

Although this picture is pretty old, I mount the 19 cu ft pony I use now the same way. I route the hose up to a clip ion the right side of my X-Tek BCD. Be careful to raise the pony high enough so the valve doesn't hit. The only time I've really had to use it, I hadn't reattached it. Don't make that mistake.

 

[Crush]

1' per second, no safety stop, with air... still beats the hell out of a CESA, doesn't it?

I would call that an assisted-CESA.

Still, not a very good plan.

I am not taking sides. As DaleC notes:

It depends on the situation and what your team decides is appropriate. 30'/min., 60'/min., no stops, full stops... It's you and your buddies choice as long as you are willing to accept the consequences.

How do you want to use a pony? If you want just enough air to make it to the surface at an accelerated rate (see bkotheimer quote above) then you can get away with a pretty small pony. Note, however, that with his emergency ascent profile you should not dive for the remainder of the day and possibly not for a few days as no agency that I am aware of recommends a 60 ft/min ascent rate between 20 ft depth and the surface. Nevertheless this ascent profile is preferable to drowning. If, on the other hand, you want to use a pony in a manner that will allow you to continue to dive later on that same day you will need more air - see DaleC's post and rock bottom calculations.

 

[SeekerOfJustice]

I have been using a 19-cuft pony and it has become an integral part of my equipment. Personally, I would recommend against mounting a pony bottle, reason being that unless you can reach the valve at any point in any position and with great ease (all of which I highly doubt when a pony is mounted), you need to access the valve. If your pony reg is leaking even a tiny bit, you might lose the very air that you are taking for redundancy. A 19 cuft pony is very small to begin with. Some people will say it's too small and recommend a 40-cuft bottle instead. If you don't mind the size and if you're not an UW photographer, I'd say go with the 40-cuft. For me the reason of getting the 19 cuft was to have something that isn't bulky enough to interfere with my photography yet still gets me safely from 120 feet to the surface including a safety stop. The 19-cuft bottle does, I've tried it from 100 ft, incl. a nice long safety stop, and still had 1000 psi at the surface. Also, with a 19 cuft you can travel on a plane. A 40 cu ft would be way too big for that.

The other reason why you want to sling a pony is that you can unclip it and hand it to a buddy if needed. It's also much easier to monitor to air pressure when it's slung, as the tank valve will dangle right in front of your chest. I have a 5-inch high-pressure hose and a regular-length regulator hose, stowed with bicycle inner tube straps. I made the rigging from polypropylene cord (Nylon expands when wet), and it works just fine. All you need is a hose clamp incl. a protective nylon tubing that fits the circumference of your tank, polyprop or polyester line, two carabiners (stainless steel is better than brass but also more expensive) and a set of instructions, which you can get here:

FKD - Deco Bottle Rigging

The cylinder clamps and carabiners you get here:

D-Rings, Belt Slides, and Clamps - Dive Gear Express
I'm attaching a pic that shows you what it looks like when it's slung. It's out of the way, yet accessible at any time.

Good luck!

So, do you just hook it to your left front D ring on your BC then once in the water?

 

[Crush]

So, do you just hook it to your left front D ring on your BC then once in the water?

Usually the left chest D-ring and the left hip D-ring.

 

[SeekerOfJustice]

Usually the left chest D-ring and the left hip D-ring.

Great! Thanks for the info.

 

[Crush]

Also, you can clip your pony on before entering the water - I usually do this and walk in for a shore dive. I recently posted a question regarding entering the water with a pony bottle via the giant stride and a roll-in entry - I was worried that the tank might knock in my teeth. Apparently many people enter the water with a pony or deco tank via the giant stride and a roll-in entry - they hold the tank in place with the crook of their elbow and otherwise use their hands to retain the mask and weight belt.

 

[AbyssalPlains]

So, do you just hook it to your left front D ring on your BC then once in the water?

Usually, I ask the boat crew to hand me my pony once I'm in the water. I have splashed with it already attached, too, which works as well. But that carries the risk of the pony whacking me in the face when splashing. I attach the pony to my left shoulder D ring and my left hip D-ring. Lately, though, I've experimented with attaching it to my right shoulder D ring and to a right hip D ring which shouldn't be there in the first place. Only reason I do that is to piss off DIR divers. No, I'm kidding. I do it because I noticed that some tech divers I recently dove with in the Red Sea attach their deco bottles to the right. But I found myself going back to the left side attachment. Seems more natural to me.

 

[AbyssalPlains]

Although this picture is pretty old, I mount the 19 cu ft pony I use now the same way. I route the hose up to a clip ion the right side of my X-Tek BCD. Be careful to raise the pony high enough so the valve doesn't hit. The only time I've really had to use it, I hadn't reattached it. Don't make that mistake.

With all due respect to Dr Bill, in my very own personal and humble opinion, this would be an entanglement hazard.

 

[GrumpyOldGuy]

With all due respect to Dr Bill, in my very own personal and humble opinion, this would be an entanglement hazard.

Not in his environment. Dr. Bill's gear looks like worn out crap, but I bet the position of the tank and hose routing is cleared from the local hazard (kelp) by his body. Probably the main tank reg and the fin straps get entangled the most. He might just know a thing or two about diving in his local, ya think?

 

[Jorgy]

The dude with all the tanks has a far far bigger issue - clear skirt mask.....:shocked2:

M