Pony Bottle Configuration

[Rhpenning]

I'm thinking of adding a small pony bottle to my set up but I don't want to get rid of my safe second--it seems a good idea to have a second connected to the primary cylinder...? My question is could I attach the pony on the left side of the tank and have the pony regulator on the left so as not to confuse it with the second/safe second? Or, do I just dump the safe second and go with the primary and pony.

Randy

 

[runvus4]

You should definately NOT dump your safe second for a pony.

What size pony are you talking about anyway and what are your intended uses? Are you just looking for something to give you peace of mind when you do an emergency ascent or are you actually looking for some sort of decent capacity bailout bottle?

Try to attach the pony to the side of your tank (either side) and see how easily you can get to it while fully clad in diving gear, holding your breath and exploding with a desire to breath. If you can get to it easy (depends on your reach/flexibility), then the side of the tank might be acceptable to you. It may be a possible point of entaglement that you can't easily clear, but that may or may not be a concern to you. If you can't get to the bottle easily, then look for another location, such as slinging it on your side. Whatever location, practice long and hard with the pony if you should get it to make sure that you can easily retrieve and deploy the bottle in a stressful situation.

Anyway, you will get lots of conflicting opionions on the benefits fo adding a small pony bottle to your setup. My personal opinion is that small ponys aren't worth the time/money/effort. If you aren't in the position to do an emergency ascent without a small pony, then you probably would need more air than what most "spare air" or "small pony bottles" can provide. If you are in a position to do an emergency ascent, then you don't need the pony bottle, and to delay the emergency ascent in order to try to get out the pony bottle, in addition to the physical exertion using up the oxygen in your lungs/increasingn desire to breath, might possibly prevent a successful emergency ascent.

 

[The Chairman]

Including a pony in your configuration does add complexity, which is why I don't dive one. Many would recommend that you bungee the pony's reg to itself. Just make sure that it is still easily accessible.

I will dive doubles if I need the redundancy. I am a firm believer that we throw way too much money at gear which is not the cause of the majority of accidents. Undertrained divers are. Think over you reasons why you are complicating your setup. You might even search the records to see what has been said about them already.

 

[Genesis]

I dive a 19cf pony slung like a stage bottle.

Its big enough to get me back to the surface in a "brown water" situation, it can be handed off, and it "disappears" underwater. Finally, I nearly always am spearfishing, and buddies are less reliable in the pursuit of that sport than otherwise.

If I'm doing a "look-see" dive with a trusted buddy, I leave the pony on the surface.

Why not just dive doubles? Mass.

While "weight" disappears underwater, mass does not. Mass requires energy to accelerate, and area requires energy to keep moving, as it increases drag. Both contribute to exertion, which contributes to CO2 loading and increases gas consumption, neither of which is desirable.

However, you must NEVER treat a pony as "extra gas". Its there for emergencies only. And you need to practice "drawing" it - the best time to do so is on your last dive of the day, at your safety stop.

Do NOT ditch your "safe second" reg. That's asking for it. I know people who do remove their "safe second" with a pony, but I strongly recommend against it, because if your BUDDY needs gas, and you have a lot in your backgas tank, why would you want to give him the smallest reservoir of air that you have?!

(I dive a 7' primary anyway, so in my case removing my "backup" wouldn't do me any good - since in any OOA situation I get the backup and the OOA diver gets the one in my mouth!)

Most of the guys I dive with both have ponies and attach them to their primary tank. I don't like that arrangement, as it just smells of entanglement trouble behind you, where you can't see to disentangle yourself! Since the entire POINT of a pony is to get you back to the surface if you lose both a primary air source AND a buddy (your buddy's octo is better than a pony, as it comes with a spare BRAIN at no extra cost!), it seems to me that the absolutely worst thing to do is to add another tank but put it where you can't clear an entanglement personally when its primary mode of use is when your buddy is out of reach (or just plain "missing"!)

 

[dc4bs]

I like that 'sling style' pony idea Genesis.
I have a 12 cf pony that I only use when I dive singles on NJ boats that 'require' a pony

The X bracket is a pain in the butt to setup because of having to re-thread the tank strap all the time.

I have two 40 cf deco bottles that I've gotten used to using with my doubles rig so it should be prety natural for me to just sling the smaller pony as well when needed.

I dunno why I never thought about doing it that way in the first place. Would have saved myself a lot of aggravation.

 

[RICHinNC]

Go to www.sea-lutions.com/ponease and check out that pony bottle rig.

I own one and it takes seconds to set up or switch from one bc to another.

You can mount the bottle valve up..down...whatever you like and adjust it so that as your right or left hand falls back it hits the valve should you experience a free flow.

I am confused as do you really want a stage bottle versus a pony. A pony is just a bail out bottle and i would think not much use below 100.....unless you have on heck of a monster pony.

Def keep your octo unless you go to an air integrated device.

 

[jonnythan]

RICHinNC once bubbled...

I am confused as do you really want a stage bottle versus a pony. A pony is just a bail out bottle and i would think not much use below 100.....unless you have on heck of a monster pony.

Def keep your octo unless you go to an air integrated device.

So how much gas *do* you need for an ascent from below 100?

 

[Soggy]

jonnythan once bubbled...


So how much gas *do* you need for an ascent from below 100?

For simplicity's sake, say you have a SAC of 1 cft/min.

At 100 fsw, you are at 4 ATMs. So, you are using 4 cft/min at the bottom. Assuming a direct ascent to the surface, you would be at an average depth of 50 fsw, which is roughly 2.5 ATM, so you will be averaging 2.5 cft/min during the ascent phase. From 100 feet, without a safety stop, it takes about 3 1/3 minutes to ascent @ 30 ft/min. So, 2.5 cft/min * 3.3 cft/min = ~8.3 cft required for a direct ascent. This is assuming you aren't sharing air with someone, which you wouldn't be with a pony.

Let's add a safety stop of 5 minutes into that. 15 feet = 1.5 ATM, thus 1.5 cft/min during the safety stop (1*1.5). 1.5 cft/min*5mins = 6 cft required for a 5 min safety stop.

6 + 8.3 = ~14.5 cft for an ascent to the surface with 5 min safety stop.

So, a 19cft bottle would be cutting it kinda close, since your SAC is likely to be higher than 1 cft/min in a highly stressful situation.


DISCLAIMER: This is a VERY rough approximation that was done in my head and should NOT be used for actual dive planning.

 

[ColdH20diving]

I use a pony bottle (19cuft) on deep dives or when using my FFM. Presently I have it attached to the right side of my tank, however, I considering carrying it in a slung position like a stage bottle. As you can see there are varing opinions on using pony bottles. IMO, if used properly, and not used to extend bottom time then go for it. Others have brought up good points, but only you know what makes sense for you. Keep your alternate air source.

 

[Doc Intrepid]

Randy,

Its not entirely clear what you want it for.

The use of pony bottles is controversial.

I dive with them, not always, but when the occasion calls for it.

When I do, I also sling them as a stage or decompression bottle.

Find out how here:
http://www.dive-rite.com/resource/stage/index.htm

This lets you get at it easily (on/off), note valve or other problems with it easily, hand it off to another diver easily, and manipulate the valve, etc. easily. The regulator is secured as shown in the photos.

As demonstrated in previous posts...if you (first) can describe what you envision using it for, it might be helpful to (second) calculate what size bottle you want. Some people use Luxfer aluminum 19s. Others use Luxfer aluminum 30s. These ride reasonably well and you do not notice them while underwater.

Regards,

Doc