Pony bottle - what size?

[Elkfriend]

Hey Folks,

The place that I will do lots of diving on a regular basis, is not deep at all, maybe 45 ft in some section, most diving will probably be around 30 - 40 ft, nothing serious.

I have 2 questions, really, one on pony bottle and one on a set of "vintage" diving gear that I got as a collateral in another deal.

Pony question:
Although lake is not deep, I think I would still carry a pony, just in case something goes wrong, but I figure I can get by with a pretty small one. Maybe even a "spare air' although I read they are junk.

Anyways, what are peoples thoughts? Is a 19cf overkill? Can I get by with a 13, maybe even even smaller? Or spare air?


Vintage gear question:
Here is the setup I am planning on (I got the stuff as a collateral on another deal, thus the 'vintage" designation)

Regular 80 tank from 1979
ONE second stage (vintage dacor, 30 yrd old), spg,
compass,
vyper diving computer
Vintage US divers aqualung BC (from late 70ties, looks a bit weird)
some kind of redundant air supply (see question above).

given the relatively shallow location, is the age of equipment too much of a risk (everything works)? Picture of the stuff is attached.

Any insights are welcome!

 

[Elkfriend]

and here is a picture of the vintage gear

ignore the fins, but I am hoping to use BC and the reg.

 

[RICHinNC]

Well you couldnt have raised a subject to stir the mud anywhere. Lots of opinions here on pony bottles.

Just to keep it short, 19 cuft is about the right size. Smaller waste of time, bigger...just dive doubles.

Let the battle begin!!!!!!!!!!!!!!!

 

[DIVERHERB]

Whoa, that's is some vintage stuff. The fins look similar to my jets so I would have no problem with them. The tank being a 1979 alum I doubt you will get anyone to fill it.The reg and bc I would have checked and serviced, if okay go for it. On dives 50 to 70 I use a 13cf pony, on deeper stuff I have a 19, anything under that as long as its no overhead and no intanglement danger I dont worry about it. I am generally spearfishing and our buddy system is same day same ocean.

 

[DaleC]

I would question whether a pony is needed for dives that will not go beyond 45ft.

We all promote redundancy but it is important to understand what it is needed for. A redundant air source for soloing should be used as a back up should your main tank lose all it's gas and you cannot ascend immediately/safely. It shouldn't be used to extend a dive or to deal with entanglement issues etc... That should be accounted for by your back gas reserves.
For such shallow dives where there is no risk from direct ascent (I believe you said before there are no powerboats allowed on the lake) a single tank with the proper amount of reserve gas should suffice. Even with a problem that causes a catostrophic loss of gas you would have enough time to ascend to the surface safely before you run dry. In such cases proper cesa skills and gas planning might be safer than the additional task loading that a pony represents.
In your case I would be more concerned about having redundant cutting tools, as entanglement by fishing line represents the greatest risk you will face (along with drunken cowboys barrelshooting that big ol fish).

Now let the battle begin!

 

[JDMerk]

I just bought a 19 today for those same day same ocean dives while spearfishing. Would have bought a 30 but they are too big to back mount...Life is all about compromises, however more air is always a good thing.

 

[Doc Harry]

14 to 19 cubic feet is fine. I use a 14 myself when I'm traveling and can't fly with my doubles. It's small and doesn't get in the way. I wouldn't mind having a 19, though.

 

[LeadTurn_SD]

I would question whether a pony is needed for dives that will not go beyond 45ft....

1+

In some cases a pony is certainly prudent even for depths this shallow, but you need to evaluate the dive environment & hazards, your skill level, your physical conditioning, etc., to determine what your "safe depth" is. By "safe depth", I mean the depth below which you would need a redundant air supply to make it to the surface in the event of an immediate catastrophic air loss (quite rare). Above your "safe depth" you are confident you can swim yourself up to the surface in a controlled manner on a single breath.

I would want a pony at shallower depths for cold & low viz conditions than I would in warm & high viz conditions.

I dive in generally good conditions. I was trained to CESA from 60' in the 70's, and I do still practice CESA's (but not often enough) from about 40' these days... so my personal "safe depth" is about 40-50 feet. I won't go below that depth without redundancy (or a buddy!).

Best wishes.

 

[dumpsterDiver]

Instead of buying a pony, get a decent BC. That thing is very old and the design is obsolete and will tend to ride up on you and be uncomfortable.

 

[SCUBA482]

I dive with a 19cf pony and don't notice it at all strapped to my steel HP100. I haven't "needed it" but have deployed it for practicing purposes. I have found there is a very sufficient amount of air in a 19cf tank. There are plenty of folks who argue to manage your gas properly and no need for a pony, but if there is one thing you MUST have underwater I'd vote for air. Thus to me the most critical redunant item would be an alternate air source. Too many arguments against a Spare Air, and for what it's worth you can buy a 19cf pony bottle, 1st & 2nd stage for the same price as a Spare Air. I also use an Air 2 vs. octo on my BC and reg setup and I like the ability to hand off the pony if in a real pinch with a buddy or just the extra piece of mind the pony provides. I can't speak to smaller bottle volumes other than mathmatically, but for the sizes and volumes you might as well go for the 19cf.

As for the gear, depends upon your budget and intentions I guess. Being a life support system, I'd have my LDS check things out to be sure they are serviceable and if money isn't an option consider acquiring new or newer gear. Just my 2 cents.