Pony Bottle, worth it?

[flots am]

No, it is not. But according to Gabrielle Giffords neither is being shot in the head. I think I'll pass on both,thank you.

Being shot in the head is nearly always damaging or fatal. A properly executed CESA is nearly always safe.

The entire point of a "no decompression" dive is that surfacing is a safe option. For a properly trained diver, the most dangerous part of running out of air would be if it's a rental tank and the owner is pissed.

flots.

 

[hypertech]

I wonder on what folks here prefer when mounting the pony bottle, valve up or down and why? (Assuming attachment to the main tank)

I prefer to sling it.

 

[spectrum]

I wonder on what folks here prefer when mounting the pony bottle, valve up or down and why? (Assuming attachment to the main tank)

This deviates from your question but I sling mine too.

1) Other than adjusting my weight allowance (if solo) it's a grab and go item with no set-up
2) It has no impact on a cylinder change.
3) It keeps my center of gravity low.
4) No costly hardware required. My sling was made from general shop supplies. I'll admit to being a hardware hoarder.
5) If need be it can be handed off.
6) Up front it's a more manageable entanglement risk.

Pete

 

[BoltSnap]

Would slinging a poney be an issue for somebody who is using a camera setup U/W?

 

[cyberick]

I agree with Mark01, I dive alot in CA and always use a Pony bottle, especially at depths over 60 feet (which is almost all of my CA dives). I am also an avid UW photographer and have never found it to be a hinderance in any way. While I have never had to use it, its a nice backup if the situation requires.

 

[BoltSnap]

I agree with Mark01, I dive alot in CA and always use a Pony bottle, especially at depths over 60 feet (which is almost all of my CA dives). I am also an avid UW photographer and have never found it to be a hinderance in any way. While I have never had to use it, its a nice backup if the situation requires.

How do you have your pony attached to you, attached to main tank or using a sling?

 

[Rocketmahn]

I dive with a back mounted 19cuft pony on all of my rec dives - even in the tropics (travels well), and have thought about adding one for the Tec dives too.

As far as I can discern there is no down-side to diving a pony, and even a small pony offers much more reliability and safety than a buddies air or diving doubles...

I don't want to rehash all of the previously discussed reason for having a pony - equipment failure, buddy too far away, OOA etc. but hope to add a few new examples.

1) For instance - a graybeard dive instructor of mine had gotten a "bad air fill" when the new guy at the shop didn't open the cooling louvers and turn on the fans in the compressor shed before he started filling tanks. The compressor eventually overheated, but before it did it burnt particles that put CO (carbon monoxide) into the breathing gas. The dive instructor AND his dive buddy both had gotten bad fills which were discovered after they started their dive and neither felt quite right, surfaced to discuss, and immediately got really bad headaches.

My point is that it is likely that you AND your dive buddy could both have bad gas from the same source, so even if your buddy is only 2' away the whole dive - it won't help if you need to use their "bad" air.
A pony filled from a separate air source provides the best redundancy (I only fill mine once or twice a year anyway). (Note: having "doubles" or a larger tank would not have helped in this situation...)

2) Diving Nitrox? What if you have mis-marked the tanks as far as the % or MOD (ie 32% and wrote 23%) or the O2 analyzer was mis-calibrated etc...
Now you have too much O2 ppo for your depth and O2 toxicity symptoms occurs rapidly. You could grab your buddy's octo (does he have the same mix?), but a pony regulator hanging around your neck would get you on safer gas much quicker - (the re-breather guys that have taken an O2 hit say that a bail out valve is necessary to switch quickly form one gas to another and that even switching to a backup regulator takes too long when you are starting to convulse..) (Note: having "doubles" or a larger tank would not help in this situation...)

3) Diving doubles for redundancy? Don't damage the manifold isolation valve and have it leak because then you can't stop all of your air from bubbling away. The manifold isolation valve and the gas are the TWO single point failure modes for doubles.

In short a Pony type of system does not have ANY failure modes in common with your main backgas, or your buddies system, and is therefore the only truly redundant airsource available to you.

Also I recommend a back mounted pony cylinder as it is out of the way.
Yes I sling stages for Tec dives, but have been smacked in the face during a giant stride, have had the bottle hit my mask while doing underwater drysuit tuck-n-rolls and I have to reach around it for the SPG.

I back mount my pony upside down as it is much easier to reach down and back (to about your kidneys) and turn it off if needed - but that's personal preference.

Also I recommend that you DO NOT mount it to your main tank, but to the BCD/STA cam bands.

Have you ever seen someone’s tank slip off their back and pull the reg out of their mouth? When that happens underwater there goes your pony too!

 

[BoltSnap]

Rocketmahn,

You bring up an interesting point about slinging tanks and water entries from high platforms (giant stride, etc.) or even a backwards roll. How do people handle this scenario to avoid the pony from riding up and hitting the diver's mask or anything else that is vital?

 

[DandyDon]

Rocketmahn,

You bring up an interesting point about slinging tanks and water entries from high platforms (giant stride, etc.) or even a backwards roll. How do people handle this scenario to avoid the pony from riding up and hitting the diver's mask or anything else that is vital?

I sling mine and backroll holding my mask & reg with one hand, the pony with the other, the same way as I do strides.

 

[Rocketmahn]

Burham,
This is only an issue with a "slung" bottle not with a backmounted 19 cuft bottle.

I sometimes have my slung bottle handed to me while in the water (and hope that I don't drop it!), sometimes I hold it down with my arm and enter, sometimes I hook it to a 15' line and retrieve it when I'm in the water.
I've never tried a backward roll off of a boat while slinging.
I've banged myself in the face while doing an underwater roll trying to get the air out of the feet of a drysuit.

It doesn't happen often at all but it you need to aware of it.