A fair and balanced look at Air2s and other combination inflators

[CuzzA]

I don't want to speak for DD, but I believe there's a thread on here where he did a bounce dive to retrieve a stuck fish from a hole in ~60 fsw, no skip breathing or holding his breath, All with just his 13 cu ft. pony. Clearly a 13 works for him. I wish his ban was up. Soon, I think.

We had 3 o rings extrude today, fortunately all top side. And there's little chance we're diving doubles in 50 feet with 4 guys on a 26 ft. pitching boat doing repetitive diving. Nor would we refit all of our tanks with H valves.

 

[Nemrod]

That there is the #1 reason I dove with a pony on single tank dives in COLD water (Tobermory). Even on shallow(ish) dives like the Niagara II (which is usually one of the coldest damn dives in Tobermory), even at 70' compared to the Arabia or Forest City at >100'), I've seen freeze flow after freeze flow. Diving a 19 - 30 gives you the gas to get it shut down and thawed. You can also hand it off and ascend independently.

Nothing wrong with pony bottles...

I never could figure the P-bottle hate either? First it was that to use the p-bottle you had to switch regs, so very hard to do ya know. Now, side mount divers do that and it is the darling of the SCUBA configurations. To me a pony bottle rig is simply a hybrid, asymmetric set of independent doubles (upon which the diver does not count the p-bottle as supply).

And off the edge of the reef, but since so many here advocate pony bottle sizes significantly close to the back gas capacity, why not include the pony bottle as gas as long as both the pony bottle and the back gas ALWAYS have enough gas to complete the dive to a safe conclusion? Either source fails just go to the other JUST as a side mount diver would do (or independent doubles back mounted).

Would a side mount diver using a pony bottle back mount the pony?

N

 

[2airishuman]

double 72's are roughly 60lbs empty. A 120 and AL19 is roughly 50lbs, so I'll give you that, but you have to add the ballast in there as double 72's will require significantly less ballast than a 120/19 combo. Somewhere between 8-10lbs, so if you're wearing that and can remove it, then you're at a wash. I also find them easier to walk around with than big singles because they sit close to your body and you don't have to make two trips or have a swinging bottle on your side that can catch any waves.

To each his own, I just don't see the point in them when light doubles are cheap and easy.

Not sure what 120s and 72s you're looking at. I have a pair of Worthington X7-120s and a pair of PSTs. All four of them are about 1 pound negative and 40 pounds when empty, the Worthingtons maybe a pound heavier and a pound more negative. AL19 is 6 pounds and neutral, empty. My LP72s are 28 pounds and neutral when empty.

So 46 pounds and neutral for the 120+19 and 56 pounds and neutral for the 2xLP72. Same amount of gas so that's a wash weight wise. 10 pound advantage to the 120s.

There are some Faber FX71s out there that are 24 pounds and slightly negative when empty that would make great doubles. They're hard to find new and nearly impossible to find used, though, and expensive, and they take 6.9" bands which are also difficult to find. I paid under $200 each for my 120s and an FX71 twinset including bands and manifold would set me back $800. There's no way I'm going to go out and buy 4 twinsets like that to replace my four 120s at those prices.

I don't want to speak for DD, but I believe there's a thread on here where he did a bounce dive to retrieve a stuck fish from a hole in ~60 fsw, no skip breathing or holding his breath, All with just his 13 cu ft. pony. Clearly a 13 works for him. I wish his ban was up. Soon, I think.

I occasionally use my pony tanks on dives for practice. I switch at depth then continue the dive on the pony until the SPG is down to 100 PSI or so. My way of internalizing the amount of air and amount of time they have. And the thing is, that you can put together a spreadsheet or something and do gas planning, and make a bunch of overly conservative assumptions about SAC and ascent rate and safety stop and time before ascent starts and so on, and convince yourself that no pony is big enough so you ought to just dive doubles. I have a 13, a 19, a 40, and a 72 and choose among them (and my twin 100s) based on the nature of the dive.

 

[kelemvor]

Get yourself one of these. Magnetic-Hose-Holder-Black-Body

I took the plastic clip off and just put the split ring directly on my left shoulder d ring. I moved the d ring down to the right position on my shoulder harness. Be sure to put a thin coat of silicone caulk over the magnet. Neodymium magnets will eventually rust.

Looks like a great solution, I ordered one. I usually coat things with clear nail polish instead of silicone.

Came in the mail today. It came with a plastic clip, but it should be easy enough to put a bolt-snap on instead. The magnet is surprisingly strong.

Not sure what 120s and 72s you're looking at. I have a pair of Worthington X7-120s and a pair of PSTs. All four of them are about 1 pound negative and 40 pounds when empty, the Worthingtons maybe a pound heavier and a pound more negative. AL19 is 6 pounds and neutral, empty. My LP72s are 28 pounds and neutral when empty.

There's a huge price premium when you go to "real" doubles. You have to buy new valves and a manifold, and bands which (unless you find em used) is going to be several hundred dollars... and then you have a doubles setup that's difficult to convert back for a single tank dive. Oh, and you might need some training, especially when it comes to manipulating isolators and such. The alternative I chose was to go sidemount, but that still required a new bcd and some training. With a pony you can also use rental tanks and just bring it along. So you don't even really need to own anything other than the pony. Doubles have their place, but imo it's only the best option for tech ow or cave.

Personally, I think it's irrelevant. I wouldn't bother with an air2 on a technical dive. I do use an air2 on recreational dive. Each configuration has it's place. Use the best tool for the job, and in my opinion an air2 is a great tool for single tank recreational dives. Less stuff to deal with.

 

[tbone1004]

@2airishuman you are correct on the weights and we agreed there, but you forgot to factor in ~4lbs for the bands and hardware, and another 3-4lbs for the manifold crossbar. That stuff is annoyingly heavy, so maybe 6 ish lb buoyancy advantage to the 72's instead of 8, but wasn't sure which 120's you were diving since the fabers are neutral.

 

[CuzzA]

Came in the mail today. It came with a plastic clip, but it should be easy enough to put a bolt-snap on instead. The magnet is surprisingly strong.

Excellent. Yes they are quite strong. I just connected mine direct to the d ring with the small split ring to keep a lower profile. A bolt snap may want to push the magnet and Air2 out away from you. Don't forget to coat the magnets.

 

[kelemvor]

Excellent. Yes they are quite strong. I just connected mine direct to the d ring with the small split ring to keep a lower profile. A bolt snap may want to push the magnet and Air2 out away from you. Don't forget to coat the magnets.

I tried one on my SPG this weekend. Took some getting used to, and I'm not sure I'll keep it on the spg. It didn't affect SPG operation, but if you don't reattach the magnet successfully, you might have a dangling gauge. After a few more dives to get used to it, it seemed like less of a problem.

It didn't affect my compass when attached to the spg, either .