Sling bottle question

[CRDiver]

Question of those who sling a pony/stage: For years I've always carried my pony backmounted and with the valve turned on. I'm going to try slinging the bottle this season. Do you generally leave the valve on or off? I've had to use my pony in the past when my main reg freeflowed at 110', and it was nice to have it instantly ready. I'm not carrying any special deco mixes, and I know those who do often pressurize the reg at the surface and then shut it down for the dive itself. If I did that, I'm concerned about the possibility that - being inexperienced in carrying a bottle like this - I could somehow bump the second stage and depressurize the reg at depth. Is this a genuine concern?

Thanks for any advice.

 

[roakey]

Do you generally leave the valve on or off?

If you're using it as a pony (which I don't recommend, but that's another discussion, of which there's dozens of them on the board) you leave it on because it's to be used for emergencies, where you need gas NOW. If it's a stage or deco bottle, you leave the valve off.

Roak

 

[strider]

If it is a slung bottle for a deco tank I would definately leave it off. It makes it much less likely you will inadvertently grab the reg and breathe off it at depth.

I love sherwood regs and have several, they are great regs, but I dislike them for sling tanks. They have a dry air bleed, which vents a very slight amount of air during the dive. This is a tiny amount of air and won't be missed, but if you turn the tank off it vents the air and equalizes the line, which can allow water in the reg, so in that case you would need to leave the reg on.

 

[HawaiiDiver]

Keep it on your back: sleeker profile, less clutter in front, easier to access your second stage in an emergency. Sling bottles are for stage/deco use, not bailout (which is what most people use a pony for).

 

[sharkmasterbc]

I dive frequently with a pony and if your just using it for a redundant airsource then definetly mount it on your back with something like an Xbracket. It is way more streamlined and also with a bit of practice you can remove it if needed. I leave my reg on cause as said a pony is for baliout and if you need gas...I usually clip off the 2ndstage to the left bottom d ring (pony is sidemounted on my right side)...

 

[redacted]

I tried both and perfer the slung pony. Back mount was OK until I switched to a BP with 2 tank straps. At that point my "ultimate pony bracket", with its 3rd strap, became too much of a hassle. With a single strap BC & Air2, the back mount pony worked well with the 2nd bungeed around my neck. Did have to de-tune to prevent freeflows, but the bungeed 2nd allowed them to be quickly detected & stopped. The slung pony is easy to rig and manage once you have practiced the manipulations required. Pretty easy to rig even on a smaller 6-pack. I dive with it pressurized and off. I repressurize it often during the dive - it almost becomes an automatic maneuver. I switched the knob yoke nut to a wing nut so as not to confuse the 2 knobs - lesson learned the hard way.

 

[Spectre]

When I back mounted, I had it upside down on my back, so I could reach back, turn on thee valve, grab the reg and use.

When I switched to a staged rig; I treat it just like a deco bottle. Charged but off; etc...

 

[Doc Intrepid]

...I'm going to try slinging the bottle this season. Do you generally leave the valve on or off? I've had to use my pony in the past when my main reg freeflowed at 110', and it was nice to have it instantly ready. I'm not carrying any special deco mixes, and I know those who do often pressurize the reg at the surface and then shut it down for the dive itself. If I did that, I'm concerned about the possibility that - being inexperienced in carrying a bottle like this - I could somehow bump the second stage and depressurize the reg at depth. Is this a genuine concern?

With all due respect, my input is that slinging the tank is a superior way to dive with it. I've dived with it both ways.

1. Entanglements often occur when tank valves encounter net or fishline. A tangled tank valve is difficult to reach and clear when its an aluminum 80 valve near the back of your head. Its far more difficult to clear when its the valve of a small bottle banded to the tank mid-way down your back.

2. You cannot reach the valve of a pony tank on your back to turn it off (or on) if its mounted valve up. Most of the time this may not be a problem. Should anything occur however, such as a freeflow in your regulator second stage, it is doubtful whether you could turn off the valve prior to your pony emptying.

3. A slung pony can be jettisoned or handed off to another diver. A pony on your back cannot.

In scuba diving the parameters that all divers face while underwater fall into two categories: those things that the diver has some control over, and those things that the diver has no control over.

All else being equal, I prefer to have control over as many things that may influence my survival as possible. The vast majority of things below I may not have control over, but whether I can reach and manipulate the valves that control my gas supply is something I can determine. When the pony bottle is slung, I can reach and manipulate the valve, avoid entanglements that I myself cannot reach, and hand the thing off or get rid of it as needed. With it on my back I can do none of those things. Its more a philosophical position than a debate over relative performance - it will still deliver gas (assuming ideal circumstances) in either position. But are you willing to bet that every dive you make will always be under ideal circumstances?

For more information, look here:http://www.diverite.com/resource/stage/index.htm

Regards,

Doc

 

[OneBrightGator]

I agree with what Doc said, a slung pony is a much better choice than backmounted for all of the reasons he's stated.

As a pony (same mix as your backgas) leave the valve open.

Ben

 

[matt_unique]

As with most everything with diving, mount it where you want it recognizing the advantages and disadvantages. I prefer to backmount my deco bottle. The advantages to me are less clutter in front and the counter balance is not as pronounced. I use Sherwood regs so it's stays on and the amount of gas lost is negligible. The entanglement accessibility compared to sling is a disadvantage (because it's behind you). With my system I cannot remove the bottle. I would never remove a bottle anyway so this does not represent a disadvantage to me. If someone needs to borrow my gas they probably need me (or benefit from having me) close by as we ascend.

Some people think the location of your mount determines the purpose of the gas but it does not.

--Matt