Pony Bottle....what is a good size 19, or 30?

[babs13]

I'm thinking of getting a pony bottle and was wondering which size is better...an AL 19 or AL 30? My general dive profile is typically under 100ft.

After doing some calculations, an AL 19 would take me up for 120 ft with a 1 minute deep stop at 60ft, 1 for OOA switch, going up ~30ft/minute, and 3 minute safety stop. I'm left with about 1.5 cubic ft, if on Al 19.

Would it better to get an AL 30 for the sake of more air, or stick with an AL 19?

[CaptnJack]

30, slung like a stage so you can see the SPG and valve. Highest resale, most useful now and in the future (e.g. can convert to a nice O2 bottle)

[Sounder]

Al30 minimum, Al40 would be great too. +1 for slinging it like a deco bottle w/ a high performance reg and spg...and practice with it too.

[Sockmonkey]

I'd normally say an AL40 to keep standard with most everyone else carries for deco... but a 30 might make more sense given your size. And +1 for slinging it.

-Eric

[Tangfish]

Sling a 40. Don't just think about your gas consumption, think about your buddy's. Also, a 40 is pretty standard for diving that you might eventually get into. I started with a 30 and now I have 2 40s and 2 80s. The 30 is my 100% O2 "hangover mix" now.

[Ken G]

I would go for the 40cf as well. You can hardly tell the difference when your in the water and you have 25% more gas in reserve. But a 30cf will work just fine too

[John Rawlings]

We're starting to sound like a chorus line!

+ 1 for an AL 40.

+ 1 for slinging it.

For all the reasons mentioned above. Plus, as an added attraction, if you ever decide you don't want it anymore, you can sell a well-maintained AL 40 in a heartbeat!

- John

[dsteding]

All the 40 proponents seem to be taking a tech diving perspective . . . I'd do the 30, because, well, for recreational NDL diving, 30 cf is plenty to get you to the surface. Since it is a pony bottle, it really is just to get one diver to the surface, and since it is an NDL dive, the "safety stop" is optional. Honestly, if you go OOA on an NDL dive, then do the switch to the pony, my guess is your ascent rate is gonna be a heck of a lot faster than 30 fpm, and your safety stop is gonna be shorter than 3 minutes at 15 fsw. Which is okay, because you haven't drowned.

And, it is worth noting the OP asked between a 19 and a 30, not what size generally . . . kinda like someone asking between TDI and IANTD and someone coming back with GUE. Just sayin'.

[CaptnJack]

All the 40 proponents seem to be taking a tech diving perspective . . . I'd do the 30, because, well, for recreational NDL diving, 30 cf is plenty to get you to the surface. Since it is a pony bottle, it really is just to get one diver to the surface, and since it is an NDL dive, the "safety stop" is optional. Honestly, if you go OOA on an NDL dive, then do the switch to the pony, my guess is your ascent rate is gonna be a heck of a lot faster than 30 fpm, and your safety stop is gonna be shorter than 3 minutes at 15 fsw. Which is okay, because you haven't drowned.

And, it is worth noting the OP asked between a 19 and a 30, not what size generally . . . kinda like someone asking between TDI and IANTD and someone coming back with GUE. Just sayin'.

Yeah the 19 is marginal recreationally. The 30 is enough for now, and as an O2 bottle (if you go this route) is plenty for some pretty big dives. If you chose not to use it as a real deco bottle, its resale to people who do want an O2 bottle is much better than trying to sell a 19. A 30 is not really much longer than a 19 and actually rides better due to its length.

If you have an OOA event diving recreationally do what Doug suggests, beat feet for the surface with your buddy. Short safety stop shallow IF it looks like you still have the gas, blow it off if you're huffing on the 30 and its <700-1000psi. Running out of gas twice is REALLY bad.

[Tangfish]

All the 40 proponents seem to be taking a tech diving perspective . . . I'd do the 30, because, well, for recreational NDL diving, 30 cf is plenty to get you to the surface. Since it is a pony bottle, it really is just to get one diver to the surface, and since it is an NDL dive, the "safety stop" is optional. Honestly, if you go OOA on an NDL dive, then do the switch to the pony, my guess is your ascent rate is gonna be a heck of a lot faster than 30 fpm, and your safety stop is gonna be shorter than 3 minutes at 15 fsw. Which is okay, because you haven't drowned.

And, it is worth noting the OP asked between a 19 and a 30, not what size generally . . . kinda like someone asking between TDI and IANTD and someone coming back with GUE. Just sayin'.

You're just saying that b/c you're a tank pimp and want more units in circulation, people upgrading, etc.

[Sockmonkey]

You're just saying that b/c you're a tank pimp and want more units in circulation, people upgrading, etc.

Pimp? Or tank ho?

-Eric

[Dusty2]

OK now from a strictly rec diver! I have been using a a pony for quite awhile. and won't dive without it. I started with a 19 and later went to a 30. I found that the 19 can go pretty fast if you are stressed or the slightest bit panicky. Your a pretty small gal and a 30 should be more than enough. As for slinging it???? I'm not a proponent of the tech side and would rather have mine out of my way. I mount mine on my main tank where it is totally hands free. I will 100% agree with the full SPG and quality second. If you go to the pony you are the one who is going to be breathing it and you want something as good as your primary. I have an spg on a medium length hose that I clip to my right D ring where it falls pretty much right at my hand when needed. I dive solo allot and and have to be totally sure that my equipment is where I need to be and completely dependable. When you go to a pony regardless of what you chose or how you decide to carry it. Get used to using it! from time to time switch over to it when you have plenty of air left in your main and breath it down to 6 or 7 hundred psi then switch back to your main so you get used to where it is how it feels and how long it lasts at given depths. You want to be completely confident that when you need it it will be there for you and you know exactly what to expect from it. In addition this assures that it is exercised regularly and the air in it is fresh. I would highly suggest that the second on the pony be an adjustable one so you can back it off to assure it doesn't leak air or free flow.

Just my 2 PSI

[Sounder]

One consideration for slinging it - if it's on your back and you get entangled in something, it may be a lot harder to free yourself. Moreover, if you have a leak from the valve or first stage, you won't see it if it's on your back. When slinging, you can see the whole thing quite easily, yet it's out of the way. If you need to detach it, you can unclip it from your d-rings or just simply cut it away. You can't cut a "pony tamer" style back-mount away, nor can you easily detach it underwater.

Tom Nic isn't a techie, and isn't in the DIR camp - he slings his bail-out. I'd bounce the question off him and see what he says. I know he has "whys" behind his election to carry it in a slung manner and is glad to discuss them.

Barbara - if you'd like to TRY slinging a 30 or 40, there are plenty of people in your circle of friends who would gladly go for a dive with you and bring one for you to try out.

[dsteding]

You're just saying that b/c you're a tank pimp and want more units in circulation, people upgrading, etc.

Actually, owning four 40s and one 30, I'm maxed out. I know, cats, dogs, dancing in streets . . .

[Pinkpadigal]

Babs,

What type of diving do you do? How large is your main bottle? What is your air consumption like? How long are your dives...do you quit because you are low, or cold? What type of enviroment do you dive in? Are you diving with a buddy or solo?

[airsix]

I'm not a tech diver, and I say sling it. Looking at divers with slung bottles you'd think they're in the way and bumping around, etc. They aren't. It's really slick. You don't even notice it. You can even sling your scooter that way and again, you hardly even notice it's there. It's quite awesome actually. I was personally amazed when I tried it. Plus you can hand off a slung bottle to another diver. Your reserve is for both divers. If you're going to put your reserve in a separate bottle you need to make sure that bottle can be used by both divers (and that it's big enough for both).

-Ben

[babs13]

After everyone's thoughts, doing the 40 makes sense. I just thought it would be a bit large for me as I'm not the biggest person. But, if I'm going to do it, might as well do it right.

+1 for slinging it, which I'll have to figure out how to rig. Looks like Bdub's link on Eric's bottle "stripper" post has a pretty good instructions on rigging. I slung Bob's 40 on a dive and I didn't really notice it underwater. I really liked how it was a pretty streamlined underwater, easy to sling to buddy, and that the reg/ gauges was easy to reach and see. Though I'm not close to tech at this juncture, the larger tank makes more sense as its also air for my buddy.

So, I'll be welcoming my little pony as the 5th member of my growing tank family.

Thanks for everyone's advice! :angry:

[bigsky]

1+ for slinging
but for a different reason
you are diving on a charter
someone comes up very bugeyed and out of air
you donate a reg
their very next step is to surface
trust me on this
that person will not let go of your reg
you are going up even if you do not want to
but if you donate a sling reg
and they will not calm down
you can hand them the bottle and back away
a little seperation can be a good thing

[lamont]

One problem with backmount, particularly diving solo, is that you can't monitor it for bubbles at the first stage. I've also seen people diving backmounted ponies with no SPG and bubbles off their first stage. With backmount you also have to figure out where to put the SPG and the pony regulator so that its easily accessible and so that the pony reg doesn't free flow without you noticing it, and so that it is always easily deployable (fatalities have occurred with full pony bottles, but with second stage pony regs that were trapped and not deployable). The backmounted pony config also often has the valve out of reach of the diver during the dive. Typically when diving slung bottles they are charged and off so that the gas will not free flow out of the bottle and this leverages the easy access to the valve -- with a backmounted pony you'll probably want to keep the valve on, which increases the risk of a free flow during the dive.

While all these problems can be solved on backmount with a bunch of thought, the slung pony solves all these issues, and gives you the ability to easily hand it off.

[Pez7378]

1+ for slinging
but for a different reason
you are diving on a charter
someone comes up very bugeyed and out of air
you donate a reg
their very next step is to surface
trust me on this
that person will not let go of your reg
you are going up even if you do not want to
but if you donate a sling reg
and they will not calm down
you can hand them the bottle and back away
a little seperation can be a good thing

[Sounder]

While all these problems can be solved on backmount with a bunch of thought, the slung pony solves all these issues, and gives you the ability to easily hand it off.

...and it looks cool too.

[CaptnJack]

1+ for slinging
but for a different reason
you are diving on a charter
someone comes up very bugeyed and out of air
you donate a reg
their very next step is to surface
trust me on this
that person will not let go of your reg
you are going up even if you do not want to
but if you donate a sling reg
and they will not calm down
you can hand them the bottle and back away
a little seperation can be a good thing

Not going to happen. They will mug you for your primary reg; they are not going to give that up for your pony nor an octo for that matter. While you fumble to try and pass that pony to them, unsure of where to clip it etc... They will probably drag you to the surface (actually they should insist on ascending lest they hoover through your remaining gas too).

Even if you did pass off the bottle...
I would NEVER let a diver who just went OOA ascend alone on a pony bottle, they have no primary buoyancy anymore if they overdump their BC they will probably sink and not remove the reg to orally inflate until the pony is dry. If they are in the condition you are so concerned about, they are probably too panicked to ditch their weights at the surface as well. A safety stop is not a deco obligation. Save their life first, then worry about going to the chamber if you somehow take a hit - takes 5 or 6 hours but its no big deal.

A little separation goes against nearly every recreational agency's OOA teachings and will probably kill them.

[rjw]

1+ for slinging
but for a different reason
you are diving on a charter
someone comes up very bugeyed and out of air
you donate a reg
their very next step is to surface
trust me on this
that person will not let go of your reg
you are going up even if you do not want to
but if you donate a sling reg
and they will not calm down
you can hand them the bottle and back away
a little seperation can be a good thing

I agree.

[John Rawlings]

I would NEVER let a diver who just went OOA ascend alone on a pony bottle....

Uhhh...where exactly was it that you think bigsky said he would let the diver ascend alone? I don't believe that he commented on that at all. Knowing him as I do, I do not believe for a second that he would ever just hand off a pony bottle and leave the diver to get themselves out of trouble on their own.

- John.

[Mongodives]

Sling a 19, small out of the way and as you calculated if you have something catastrophic at 120fSW you have enough air to ascend safely.
If you really want to know, I'm sure there are enough people on this board with enough equipment to let you try before you buy.