Tips for backmounting an AL19 pony?

[afieldofblue]

I used to use the Pony Tamer system but it required bands / brackets on the primary tank.... Now I have the Quickdraw system and won't ever go back. Rock solid attachment.

Thanks - how adaptable is the Shark system in terms of primary tank length? Would it be possible to use with a short tank like a steel 10L or is the valve hooking pole too long and only fit for AL80 style long tanks?
The typical rental steel tank in Japan is the 10L steel, and I'm wondering how a mount like this would fare should longer / aluminium tanks be unavailable.

Typical Japanese steel tank vs. Japanese aluminium

steel rentals



thanks

 

[justinthedeeps]

No, not practical for multiple reasons - major one is that I'm in Japan and tanks need to be KHK certified to be filled, and very few types of cylinders are imported here - a pony itself is hard (near impossible...) to find, the one I'm buying was actually re-KHK certified, including the valve, in Japan, which is a complex process.
See the O2+N2 restamping (instead of air) + official Japanese markings

View attachment 895410 View attachment 895411
Most people using smaller cylinders (for rebs or stages) will use non-KHK cylinders, and fill them privately (which is illegal). They cannot be hydro'ed as well. Same goes for valves.
The seller will have it rehydro'ed for me before shipping. It's a unicorn here, where DOT certified tanks cannot be filled or hydro'ed.
So LP50 twinsets... not going to happen in my neck of the woods.

The other issue is weight for shore dives with a camera, and price of fills, equipment cost, manifold, all for limited benefits - it's just not practical.
I'ved dived with a 3L pony a few times in the past (borrowed rig) and really liked it. It was strapped-on (don't remember exactly how, this was a while back) but not floppy at all.

Only dived there briefly so far, thanks for giving some context re: some of the odd ways SCUBA there seems to be held behind vs. modern global standards (hard to find DIN/convertible valves too?)

 

[justinthedeeps]

As another diver who has dived a bunch of setups, Including singles, twinsets, sidemount, rebreathers, DPVs, full sized camera rigs etc,

You wouldn't catch me dead hardwaring a pony to a backmount single, when it is sooo much simpler, easier, more modular, separately portable etc etc to just side-clip on the pony per "stage" practices.

If you're experiencing chest clutter etc, then there a lot of ways of mitigating that by adjusting and snugging up the rigging (commonly way too much slack and play/dangling), using shockers or bungees on the top end, low-clipping the top to a second chest D ring, all of that is much easier than clamping ponys onto backmounts (especially when traveling or hiring/using cylinders you don't own etc)

 

[afieldofblue]

Only dived there briefly so far, thanks for giving some context re: some of the odd ways SCUBA there seems to be held behind vs. modern global standards (hard to find DIN/convertible valves too?)

Yes, Japanese diving is definitely in some sort of cultural bubble, where isolation reinforced both by language issues and a relative indifference to what is going on elsewhere, unfortunately.
DIN / convertible valves are pretty much only found in operations run by European foreigners or tech friendly shops, Japanese or foreign, but these rarely do tank rentals only. After years with no issues on convertible valves including in relatively remote east Bali, I've had to dig out the yoke adapter again...

And when it comes to cylinders and valves there is an added layer of complexity with Japan's own High Pressure Gas Safety Act regulations, which requires tanks to be KHK certified to be legally useable in the country (DOT tanks cannot legally be hydro'ed or filled here).
The 19cu pony I found is a Luxfer which was re-certified in the Japanese system (doing this is something of a bureacratic nightmare, I looked into it and it implies send the tanks to Tokyo, with translated DOT documentation etc...), so I will be able to get it filled here.

Other divers using smaller cylinders (stages, rebreather cylinders, ponies etc) just skip the Japanese certification and fill their tanks independently (or transfill), but this is actually illegal and would cause issues in an accident investigation...

 

[afieldofblue]

As another diver who has dived a bunch of setups, Including singles, twinsets, sidemount, rebreathers, DPVs, full sized camera rigs etc,

You wouldn't catch me dead hardwaring a pony to a backmount single, when it is sooo much simpler, easier, more modular, separately portable etc etc to just side-clip on the pony per "stage" practices.

If you're experiencing chest clutter etc, then there a ways of mitigating that by adjusting and snugging up the rigging (commonly way too much slack and play/dangling), using shockers or bungles on the top end, low-clipping the top to a second chest D ring, all of that is much easier than clamping ponys onto backmounts (especially when traveling or hiring/using cylinders you don't own etc)

Thanks but as explained above, I shoot video, especially super macro, where I am almost lying on the ground due to camera/screen consideration, and want nothing on my chest or under my arm.
To give an example, I rig my LPI hose otherwise it's in the sand, and in this kind of context I know for sure will be pushing the slung tank + reg out of the way behind me. Meaning I would probably end up rigging it behind me anyway, which defeats the purpose.
I'll only do solo shore dives with this setup (no boat/travel), and for entries/exits much prefer having nothing dangling other than the camera rig if I need to clip it because it's a little hairy.

Backmounted is much easier for this application, and will make my life easier for walk-in entries/exits with the camera. Most clamping solutions offered here are pretty straightforward, and simply imply clipping one single camband/strap to the primary tank, which is fine with me.

There's really no reason for me to add the complication of separate portable element to the kit. It's quite the opposite of what I'm after for this application.

 

[justinthedeeps]

Thanks but as explained above, I shoot video, especially super macro, where I am almost lying on the ground due to camera/screen consideration, and want nothing on my chest or under my arm.
To give an example, I rig my LPI hose otherwise it's in the sand, and in this kind of context I know for sure will be pushing the slung tank + reg out of the way behind me. Meaning I would probably end up rigging it behind me anyway, which defeats the purpose.
I'll only do solo shore dives with this setup (no boat/travel), and for entries/exits much prefer having nothing dangling other than the camera rig if I need to clip it because it's a little hairy.

Backmounted is much easier for this application, and will make my life easier for walk-in entries/exits with the camera. Most clamping solutions offered here are pretty straightforward, and simply imply clipping one single camband/strap to the primary tank, which is fine with me.

There's really no reason for me to add the complication of separate portable element to the kit. It's quite the opposite of what I'm after for this application.

You're already adding the extra cylinder, regulator, hose etc, in either approach. So side clipping is not more complicated than trying to hard clamp cylinders together. And when you go to change cylinders, it's a bigger pain to faff around with the "back pony" config than to simply set aside the small pony stage. And keep things modular.

In regard to filming, there are hundreds of professional filmers who have no trouble getting world class footage (including supermacro subjects at sand level) while employing bailout cylinders of various sizes if/as needed.

I have no trouble doing macro with stages, provided that cylinders are appropriately rigged and clipped (and often bungeed) so that it doesn't actually get in the way. There are several ways of clipping bailout stages, you could even clip the top end onto a hip or tail D ring if you wanted to, provided that the cylinder is open, the gas is breathable (MOD) and you give yourself easy access to the second stage on a necklace reg.

 

[justinthedeeps]

Re: boat and shore logistics I see your reasoning about a single-unit / multi-cylinder approach feeling simpler for entries and exits. A lot of Seattle/Vancouver divers dive this way

But having more weight affixed higher up on the rig isn't necessarily great either, in testy conditions

For Hawaii rough lava shore dives, I sometimes just hurl a stage in first, by itself! Quick clip it onto a hip ring after initial entry, walk/swim out a bit further, reclip/reposition as necessary. Modularity gives options

Depending on the site conditions you could also use a tagline to assist pulling stage cylinders in and out of the water (though I have not needed to yet, including with camera gear and DPV..)

 

[afieldofblue]

You're already adding the extra cylinder, regulator, hose etc, in either approach. So side clipping is not more complicated than trying to hard clamp cylinders together. And when you go to change cylinders, it's a bigger pain to faff around with the "back pony" config than to simply set aside the small pony stage. And keep things modular.

In regard to filming, there are hundreds of professional filmers who have no trouble getting world class footage (including supermacro subjects at sand level) while employing bailout cylinders of various sizes if/as needed.

I have no trouble doing macro with stages, provided that cylinders are appropriately rigged and clipped (and often bungeed) so that it doesn't actually get in the way. There are several ways of clipping bailout stages, you could even clip the top end onto a hip or tail D ring if you wanted to, provided that the cylinder is open, the gas is breathable (MOD) and you give yourself easy access to the second stage on a necklace reg.

Understood, but it's not what I would like to do at the moment.
As for professional videographers, they don't have the same constraints as I have, in that they have an HDMI screen and can position themselves over the rig. I don't have an HDMI output on my rig, and use an screen magnifier on the housing, meaning I need to be at housing level.
It's all kitchen stuff. I work on a quadripod, and make microfocus adjustements to the camera, for which I need to be horizontal camera level, not above. This means very low, and the last thing i want in these situations is a cylinder clipped on me rather than on the tank, behind me.

But frankly, do i really need to go in this here again, in a thread where i specifically asked for advice on backmounting options?

I totally understand why people might prefer slinging, or sidemount, or even twinsets or rebs, and I also know why I don't find it practical to it for what I do at the moment, let's just leave it at that.

And in a few month or years I see the light and move on to a sling, I'll make sure to credit you and Gamon for have tried to show me the errors of my ways.

I've noticed this something of a constant in threads on the subject, and it's the second time in this one.
I'm sure it's coming from good intentions, and I appreciate the time taken to share of knowledge and opinions, but I also don't think what I'm planning on doing is wrong, or at least to the point that I should need to justify the choice of backmounting a 19cf pony tank in this manner.

Thank you.

 

[gamon]

I've noticed this something of a constant in threads on the subject, and it's the second time in this one.
I'm sure it's coming from good intentions, and I appreciate the time taken to share of knowledge and opinions, but I also don't think what I'm planning on doing is wrong, or at least to the point that I should need to justify the choice of backmounting a 19cf pony tank in this manner.

Thank you.

There's no right or wrong, however your stubborn and closeminded attitude doesn't do you any favors. You've chosen to disregard a proven and superior technique because you have decided, without even trying it, that it won't work for you.

A constant in many threads besides the highly opinionated answers is that often a person will start a thread and ask the wrong question expecting to get right answers that support their often incorrect way of thinking and get defensive when few or none agree with their suggested technique.

 

[happy-diver]

Duck and cover duck and cover, the slingers are coming the slingers are coming

Plenty to say but not much diving substance

Beware the slingers!