Pony tank thoughts/advice?

[sonofzell]

Good morning all!

Relatively new (<50 dives) diver here... purchased a few used tanks earlier this year, one of which was an older 19cf pony. It was sort of a bonus add-on to the sale, as it's significantly older and was out of hydro. It just came back from hydro/viz this week, and I'm just curious to hear anyone's thoughts or suggestions on using it.

I dive purely for recreation; the vast majority of my diving is done at my local quarry in PA (Dutch Springs) and around the FL treasure coast where we typically visit family a few times a year. I only obtained my aow cert this year, so I haven't been able to get out off the NJ coast yet... any other dive opportunities are tropical vacations (which are few, far between, and for which I would typically rent tanks anyway).

As for the pony, I've never dove with a redundant tank before, and truthfully haven't felt a dire "need" for one, but since obtaining this one as somewhat of a gift, it seems silly not to at least try it out. I had a spare octo with a 24" hose and an old first stage that I threw on it. Both seem to operate perfectly, although I can't help feeling the hose is a bit long for backup use (??). I've ordered a button spg, but now I'm to point of considering exactly how the heck I plan to carry this extra bottle. In case it's relevant, I typically try to be a "minimalist" diver; I use a back inflate bc with dual straps and most often use a single al80 cylinder (unless I'm renting and end up with something different).

1. I've seen a lot of articles that suggest pros/cons to "mounting" vs "slinging" pony tanks. As a rec only diver with no plans to stage dive in the near future, I'm inclined to believe the former is likely best suited for me... I welcome any thoughts regarding the benefits of either method.

2. For attachment, it's somewhat unclear on the exact method(s) of including a second bottle. The tanks I purchased recently have D ring attachments towards the bottoms, which the seller indicated he used "for ponies". I should have (but didn't) ask him to elaborate, and I have to admit, I'm simply not sure exactly HOW these were used. The rings are positioned such that there is a ring on either side of the tank (3/9 o'clock relative to my body); I can only assume they acted as mount points to "sling" the pony on either side of the body, using a shoulder ring to attach the top (??). The only other configuration I could see would be if the pony were simply "hanging" off the ring at the bottom of the main cylinder (which would seem pretty counter-intuitive and arguably dangerous to me).
I've seen products that attach ponies to the main bcd straps, using either their own cam straps or using a "bag" of sorts. I'm curious if there's any perceived advantages/disadvantages to either.

3. Lastly, if I presume that my pony will be "mounted" to the primary tank, what is the typical deployment method? Looking at products online, it's unclear if there's any sort of release mechanism to separate the tanks quickly, and with my wing-style bladder, it doesn't seem like I'd be able to easily grab the pony at depth with my bc on. With the "bag style" mounts, I even envisioned mounting the pony in an inverted position, so that I could reach around under the wing, release the closures around the pony neck and allow it to slide out downward. Again, this seems wildly unsafe, and the thoughts of dropping a spare tank inadvertently, in or out of the water, literally make me cringe! The only deployment method I can imagine then for an ooa emergency would be removing my bc to separate the backup tank for use. While this would seem like a very sensible method to me, I'm somewhat surprised that I haven't really been able to find any instructionals that support or invalidate doing this.

I'm sure I may be making this more complicated than it needs to be (that's kinda my thing lol), so I'm eager to hear anyone's suggestions on the best way for me to begin using/practicing diving with a backup bottle. Although it's not necessarily something I would have sought out on my own, I'm certainly all for any safety redundancies now that I have it. I also know it's a requirement for many off-shore jersey dives, which I'd like to start doing more of in the next few seasons.

Thanks in advance for any suggestions or guidance you may have to offer!

Cheers,

Kirk

 

[Marie13]

Sling your pony.

Get a stage kit from DGX. Make sure it’s for the right diameter tank.

If you have an AL19, X-small is the one you want.

DGX Premium Webbing Stage Strap Kit

You clip pony to left chest D ring and left hip D ring (or D rings in approximate locations if you have a jacket BC). Before you rig the tank: measure distance between the chest and hip D rings. Then on pony measure that distance from middle of valve opening down tank. Mark with a sharpie. That’s where the bottom worm clamp will go.

40” hose is standard pony length.

Don't mount your pony to your back tank. Causes a number of issues. Trying to find the thread that had a lot of discussion about this recently.

 

[Marie13]

This is the thread I was referring to with tank mount pony discussion.

Steel HP 23 vs Al 19 redundant air source

 

[JohnN]

Good morning all!

Relatively new (<50 dives) diver here... purchased a few used tanks earlier this year, one of which was an older 19cf pony. It was sort of a bonus add-on to the sale, as it's significantly older and was out of hydro. It just came back from hydro/viz this week, and I'm just curious to hear anyone's thoughts or suggestions on using it.

I dive purely for recreation; the vast majority of my diving is done at my local quarry in PA (Dutch Springs) and around the FL treasure coast where we typically visit family a few times a year. I only obtained my aow cert this year, so I haven't been able to get out off the NJ coast yet... any other dive opportunities are tropical vacations (which are few, far between, and for which I would typically rent tanks anyway).

As for the pony, I've never dove with a redundant tank before, and truthfully haven't felt a dire "need" for one, but since obtaining this one as somewhat of a gift, it seems silly not to at least try it out. I had a spare octo with a 24" hose and an old first stage that I threw on it. Both seem to operate perfectly, although I can't help feeling the hose is a bit long for backup use (??). I've ordered a button spg, but now I'm to point of considering exactly how the heck I plan to carry this extra bottle. In case it's relevant, I typically try to be a "minimalist" diver; I use a back inflate bc with dual straps and most often use a single al80 cylinder (unless I'm renting and end up with something different).

1. I've seen a lot of articles that suggest pros/cons to "mounting" vs "slinging" pony tanks. As a rec only diver with no plans to stage dive in the near future, I'm inclined to believe the former is likely best suited for me... I welcome any thoughts regarding the benefits of either method.

2. For attachment, it's somewhat unclear on the exact method(s) of including a second bottle. The tanks I purchased recently have D ring attachments towards the bottoms, which the seller indicated he used "for ponies". I should have (but didn't) ask him to elaborate, and I have to admit, I'm simply not sure exactly HOW these were used. The rings are positioned such that there is a ring on either side of the tank (3/9 o'clock relative to my body); I can only assume they acted as mount points to "sling" the pony on either side of the body, using a shoulder ring to attach the top (??). The only other configuration I could see would be if the pony were simply "hanging" off the ring at the bottom of the main cylinder (which would seem pretty counter-intuitive and arguably dangerous to me).
I've seen products that attach ponies to the main bcd straps, using either their own cam straps or using a "bag" of sorts. I'm curious if there's any perceived advantages/disadvantages to either.

3. Lastly, if I presume that my pony will be "mounted" to the primary tank, what is the typical deployment method? Looking at products online, it's unclear if there's any sort of release mechanism to separate the tanks quickly, and with my wing-style bladder, it doesn't seem like I'd be able to easily grab the pony at depth with my bc on. With the "bag style" mounts, I even envisioned mounting the pony in an inverted position, so that I could reach around under the wing, release the closures around the pony neck and allow it to slide out downward. Again, this seems wildly unsafe, and the thoughts of dropping a spare tank inadvertently, in or out of the water, literally make me cringe! The only deployment method I can imagine then for an ooa emergency would be removing my bc to separate the backup tank for use. While this would seem like a very sensible method to me, I'm somewhat surprised that I haven't really been able to find any instructionals that support or invalidate doing this.

I'm sure I may be making this more complicated than it needs to be (that's kinda my thing lol), so I'm eager to hear anyone's suggestions on the best way for me to begin using/practicing diving with a backup bottle. Although it's not necessarily something I would have sought out on my own, I'm certainly all for any safety redundancies now that I have it. I also know it's a requirement for many off-shore jersey dives, which I'd like to start doing more of in the next few seasons.

Thanks in advance for any suggestions or guidance you may have to offer!

Cheers,

Kirk

+1 to what @Marie13 said. Sling the pony and put a button gauge on the first stage. The only purpose of the button gauge is to confirm you have air in the tank when you start your dive. That pony is not part of your gas planning, it's there in case poo hits the fan. If you mount it to your tank, and it decides to leak you may never notice it.

A final bit of advice is to use a DIN valve and first stage. If poo does impact the fan, you really don't want to have two knobs that could be turned in a moment of haste

 

[RyanT]

If you mount it to your tank, and it decides to leak you may never notice it.

Just to add to @JohnN's already good advice, if you mount the pony to your main tank, the center of gravity will be higher. It will tend to want to roll you out of trim. By slinging the pony, you lower its center of gravity and it will ride much more comfortably.

 

[Bob DBF]

I choose to sling my pony because I choose on which dives I feel it is appropriate to take the pony. Attaching it to a tank, in my case, means changing it between tanks from dive to dive, which could get inconvenient and/or costly depending on how it's done.

 

[scubadada]

Hi @sonofzell

I sling my pony and use the webbing kit from DGX cited by @Marie13 The proper setup is shown on the DGX website

I chose to use a full size SPG on a short hose rather than a button gauge, to make it easier to follow cylinder pressure if necessary. I turn my pony on before a dive, others choose to charge it and then turn it off. With the valve, regulator, and SPG right in front of me, I would be aware of any gas loss. I use my pony for solo diving.

I assume you dive with a buddy. To be adept at carrying and deploying a pony is a valuable skill, nevertheless. In an OOA situation, you could use it yourself or hand it off to another diver. If you decide on solo diving, you will already have the skill. You should periodically practice deploying it, to keep your skill up.

It is a good idea to know how much gas you might need for an intended purpose. For example, to make a normal direct ascent from 130 feet, it would take a little over 4 min. Most recommend using a increased RMV value, perhaps twice your avg RMV, to account for the emergent situation. If you use a RMV of 1.0 cu ft/min, that would be 12.9 cu ft. Some would add a minute on the bottom to take care of issues, that would be 4.9 cu ft. Some would also add in a routine SS, that would be 4.4cu ft. Time at the bottom, a normal ascent, and a 3 min safety stop at a RMV of 1.0 cu ft/min would take 22.2 cu ft, a bit more than you would have in an AL19. Of course, if push came to shove, you could make a faster ascent and you could skip the SS on a no stop dive. I would encourage you to make some sample calculations using your own RMV. My example is pretty reasonable, it appears that an RMV in the 0.5s is about average for the 362 divers who have responded to my SB poll
Average Gas Consumption

Take care, good diving,

Craig

 

[sonofzell]

Wow guys - thank you. Great advice as always!

The benefits of slinging vs mounting are pretty clear, and to be honest it seems like the "easier" option anyway. Although I really have no desire for the added bulk, I'm definitely going to make some test runs with it to gain some comfort and familiarity. With practice, I hope to become proficient with the extra tank when I don't really need it so it's not a distraction when I do!

"40” hose is standard pony length" @Marie13 This is definitely longer than I would have thought to consider but makes perfect sense if giving the extra air to a buddy. Is there a standard practice for managing the hose? I know there are retention bands, but in terms of the actual hose position, is it common to coil the hose or any other strategies for keeping the second octo easily accessible (yet out-of-my-way)?

I'm also curious as to why you suggest a left-side mount. With no rationale behind it, my "vision" of a slung pony would be on my right... I'm certainly not averse to either, it seems more ergonomic in my head. Is the left side recommendation in order to isolate the pony from the primary tank's regs/hoses? I'm just curious if your suggestion is arbitrary or a purposed placement... If I'm practicing slinging a pony, I surely want to practice it properly.

"use a DIN valve and first stage" @JohnN Duly noted and understood. As mentioned, I'm really working with spare parts as of now, which consists entirely of yokes. I'll certainly keep your suggestion in mind if/when I get to the point of investing in carrying the pony more often, but your reasoning is not lost on me!

"I assume you dive with a buddy" @scubadada 99.9% of the time, yes. I will occasionally go solo on shallow inland spots (specifically Blue Heron Bridge which I try to hit at least once a year). My 15yo daughter just certified ow this summer, so the majority of my diving is done with one or both of my girls. With the oldest heading to college in the fall (in FL for marine biology), I plan to jump on this opportunity for us both to gain a lot of practice with a second tank! She's never dove without me, so you can imagine the sleepless nights I have in store sending her 1,000 miles away and knowing she's going to be logging dives like crazy... ANY additional safety skills we can develop in the meantime are more than welcome!

I'm also curious about what people's experiences are with weighting when adding a redundant tank. The s19 isn't crazy in terms of size or weight, but I imagine it's reasonable to expect that I might want to reduce / redistribute pocket weight to compensate for the extra cylinder(???)

 

[Marie13]

Standard is on the left.

Hose just goes in a U shape and gets stuffed under the retention band(s).

 

[rjack321]

I'm also curious about what people's experiences are with weighting when adding a redundant tank. The s19 isn't crazy in terms of size or weight, but I imagine it's reasonable to expect that I might want to reduce / redistribute pocket weight to compensate for the extra cylinder(???)

weight yourself so you are neutral when they are both empty, because the 2nd valve and reg can be a little heavy you may get to take off a pound or 2