Air Buddy Revisited; Semi-Solo Diving

[jsnorman]

I don't want to rehash the previous two threads on Air Buddy, except to note that for the pro AB folks (all two of them), the agnostics (including several who questioned what possible advantage AB could offer), and the many skeptics (none of whom had actually used the AB), all of the posts focused on use of the AB as a replacement for the alternate air source (typically octo) in a buddy breathing situation. That isn't what I bought my AB for (in fact, I would never give up my pony to a panicked buddy!)

There are two reasons I bought my AB but I would like input on what more experienced divers think **in light of my specific intended use**. I have not yet dived the AB and I am planning to spend some quality pool time before going out. So I would really appreciate some thoughtful and experienced divers' responses.

But first things first ...

1) Why I Bought the Air Buddy

There are two circumstances that led me to buy my Air Buddy (along with a 6 cubic foot pony tank).

First, my buddies seem to often be suicidal idiots. In the past 9 years, I usually have met my buddy on the boat (my "real" buddy unfortunately must care for our children whilst I dive, at least for now). I have already had to rescue my "buddy" in two cases in that time, due to utter stupidity on my stranger-buddy's part (in the first, my erstwhile buddy's 1st stage started freeflowing, and he later admitted he hadn't had his regulator serviced in several dive trips; in the second my buddy sucked his tank dry and never told me he was low). One of these rescues happened while I was still a relative novice myself (on my first night dive too!) and I was really turned off of stranger-buddies. I got over it obviously, but my distrust of stranger-buddies continues even though I must rely on them if I want to continue diving.

Second, I took up UW photography several years ago and I have started to get more serious about it. In my last couple of trips, my stranger-buddies have been frustrated by my slow pace and zoomed off without me. Which, really, was fine with me because I didn't really want another rescue under my belt (just kidding, kinda sort of). After this happened the first time, I bought a Spare Air unit (the "large" one at 3 cubic feet), but as has been addressed elsewhere that would hardly do the trick for anything other than an emergency ascent if I am at depth.

So, this time out I got my pony bottle and the Air Buddy to replace my Spare Air cylinder. I haven't used it yet, and I am honestly seeking opinions on it from folks who have more experience and hopefully HAVE used it.

I do not intend to replace my octo (which is already streamlined through use of Oceanics integrated second stage + BCD inflator hose). Rather, I view the AB as a failsafe given the fact that, in essence, I am often relatively alone in the water.

Consider that the AB provides a secondary air source (pony), secondary first stage regulator, *and* secondary second stage (the AB itself). I have seen a first stage fail and if that happened to me while I was snapping shots of a some coral head at a 100 feet, my octo would be of little use. Moreover, I have had a buddy grab my primary out of my mouth I would much rather have a completely independent, alternate air source in that situation.

Also, streamlining is very important to my photography, so having just got rid of my octo (or rather moving my octo to be a part of the BDC inflator hose), I really don't want to add my octo **back** if I don't have to.

So that is why I bought the AB as part of my hopefully failsafe pony setup. To reiterate, I am not going to get rid of my octo (why would I since its already integrated with my BCD!).

2) Alternatives

Here are the alternatives I thought of for my situation (a situation, by the way, that I don't think is uncommon), my intended setup is (b):

a) Use a "normal" second stage, attached to the pony and pony 1st stage. I was thinking about on the the streamlined octo setups like the Oceanic Slimiline 2. Still, its an extra hose and takes up a D ring on my BCD. Also, the addition of a hose and second stage creates at least two additional points of potential failure (the hose and hose connection itself, and the second stage). However, it is easy to use and I can pick a second stage with a good record of safety from a trusted company like Atomic or Oceanic.

b) Air Buddy attached directly to pony and pony first stage. Very streamlined (for a pony). One disadvantage is that I don't have any easy way to get to the tank; I would have to remove my BCD underwater, and release the pony strap - not a huge deal, but it does make me rethink whether I should just use an octo and hose. I would really love a quick release strap that I could use to pull the pony off my back without removing my BCD, but I cannot find anything like that. Another disadvantage is that Air Buddy's have relatively limited use, and it is a small company. I would really prefer my lifesaving equipment come from a more established company.

c) Air Buddy attached to a hose. I don't see any real advantage to this, especially since there are really tiny second stages not much bigger than the Air Buddy available, and I would still have a hose hanging off me and use a D ring to hold the air buddy. True, the Air Buddy shoudl be less prone to failure versus a traditional second stage (simpler design, less moving parts) but that is offset by the unknown quality of a small company with a limited market (IMHO).

d) Stick with the Spare Air. It is very small and easy to streamline, easy to use, and provides enough air for a controlled emergency ascent from 60 or so feet. Of course, at greater depth I am probably risking DCS to make it to the surface before the Spare Air runs out, but even that is still better than running out of air totally in a massive failure situation. I do not go below 130 feet FYI.

e) Stop diving on boats with buddy strangers, and wait a few years for my kids to grow up before taking up scuba again. Okay, this one was just for completeness. Not a chance!

Would love input, advice, similar rigs, other ideas.

My first post FYI, great board!

 

[vladimir]

Air Buddy, Spare Air, and a 6 cubic foot pony, all in the same post? Sounds trollish.

 

[*dave*]

Air Buddy, Spare Air, and a 6 cubic foot pony, all in the same post? Sounds trollish.

ya think? nah....

 

[Thalassamania]

I have an AB. I was given it nine years ago. It has been used irregularly. It has never had any sort of service or maintenance except a rinse after most dives. It still works fine.

That said: I think that three cubic feet is no where near enough, and six cubes is not a whole lot better unless all your dives are really shallow. The question here is not the delivery system, it is the volume behind it. When I started using a pony it was with a 13, I soon changed that to a 40. I see that as a sensible minimum.

As to the delivery system: regardless of what the nay-sayers tell you, if they've not used an AB they have no idea what they are talking about, if you are comfortable with it and practice with it regularly, I'm sure that it will serve you fine.

 

[bkotheimer]

JS, do some searches here on the boards. There are TONS of threads on Spare Air and on pony tanks. There are even tons of posts that merely index all the tons of previous posts, so I won't even attempt it here.

What you'll find is that, by and large, the members of the SB community who DO believe in pony bottles are in favor of a 19cf tank or more and are all about rigging it like a stage bottle and slinging it. I use only a 13 myself, and it's backmounted with a second stage on a hose bungied to the side like a stage bottle.

I doubt you're trolling. You wrote way too much for that. And I feel you on the insta-buddy situation, especially the way they leave you in the dust when you're trying to get a couple of good shots.

 

[=C=]

2) Alternatives

Here are the alternatives I thought of for my situation (a situation, by the way, that I don't think is uncommon), my intended setup is....

Would love input, advice, similar rigs, other ideas.

My first post FYI, great board!

Sooo if I understand correctly you would like to dive alone, buddies are troublesome, and air is your only concern.

There is a system that exists where as your bcd/AIR2 is on a separate supply of air and you can switch to breath off this supply or use both supplies together.

Manifolded doubles could be a solution for you. You don't have to have steel 120s there are other options.

If you do decide to dive alone and understand its risks (air being just one of them) I would recommend the SDI solo diver class which could benefit you... There are several threads on SB about it...

 

[jsnorman]

What you'll find is that, by and large, the members of the SB community who DO believe in pony bottles are in favor of a 19cf tank or more and are all about rigging it like a stage bottle and slinging it. I use only a 13 myself, and it's backmounted with a second stage on a hose bungied to the side like a stage bottle.

Thanks. Okay, it looks like I definitely underestimated my air supply needs as it seems I should be thinking of 2-4 times that volume. Does anyone know of a good simulator that will take into account pressure changes on ascent to determine what I realistically need for the emergency air supply? I know I could probably figure it out with moore's law and all, but its been a long time since my chemistry class in college, and to be honest that was not my best subject :shocked2: What I want to do is assume worst case (for me) of starting at 130 feet and ascending at the maximum safe ascent rate (which I know varies by depth). The calculation seems fairly complicated. I had assumed 30/fpm, which means I am at the surface in a little over 4 minutes if I lose my main tank at 130 feet. Naively I guess, it seemed like a 6 cubic foot tank would give me 4 minutes by the simple (and probably wrong) math that an 80 gives me an hour.. but I am not taking partial pressure and all that into account so I am totally open to reconsidering this, I still have plenty of time to get a bigger tank before my next dive in April. I am a pretty calm diver, I have been in emergencies and do not panic (myself anyway, can't say that for my buddies lol).

And no, I am not trolling. Sorry to those who thought I was, but I made it clear I did do searches on this before posting, and found and read in full the two prior threads on Air Buddy. I don't think those threads really addressed using the Air Buddy as a redundant backup which is why I am posting this. I DO understand Spare Air at 3 cubic feet merely prolongs my death; I bought my Spare Air in the middle of a dive trip on Grand Cayman after being abandoned by my "buddy" while I was taking pictures decided against using it after that trip when I did some research on it (on this board) ... long time lurker, first time poster. Hopefully that appeases the haters ;-)

 

[jsnorman]

I have an AB. I was given it nine years ago. It has been used irregularly. It has never had any sort of service or maintenance except a rinse after most dives. It still works fine.

Thal, thanks I do really appreciate your original post and experience with AB. I love the simplicity of the thing especially since it is a backup that needs to be totally reliable and moving parts and points of failure = bad.

How do you rig the pony and AB on your setup? I thought I read in your previous posts that you attach the AB to a hose on your pony, and use the AB/pony in lieu of your octo - is that right?

What you'll find is that, by and large, the members of the SB community who DO believe in pony bottles are in favor of a 19cf tank or more and are all about rigging it like a stage bottle and slinging it. I use only a 13 myself, and it's backmounted with a second stage on a hose bungied to the side like a stage bottle.

Re slinging the tank, is there a good source of info on this? I did some searches but the term is too common and I am getting a lot of unrelated crap in my search results... I have seen pictures on this board of a "slung" tank, and I found the DIY-scuba site which shows how to rig the pony for a "sling"... but I don't really understand how the tank is actually hooked on to the BCD plate and what equipment to use. I don't have a technical rig, so maybe that is part of the problem. Also, the sling method really seems likely to bump against coral while I am taking pictures, but I know many others use it. Any more info would be appreciated.

Sooo if I understand correctly you would like to dive alone, buddies are troublesome, and air is your only concern.

There is a system that exists where as your bcd/AIR2 is on a separate supply of air and you can switch to breath off this supply or use both supplies together.
...
If you do decide to dive alone and understand its risks (air being just one of them) I would recommend the SDI solo diver class which could benefit you... There are several threads on SB about it...

Yes, that is correct though totally alone I probably wouldn't do as I always boat dive with a group .. but effectively I am alone on most dives when I bring my camera, even if there is another photographer to buddy with me we are usually both so absorbed in our shots that I would like to start thinking like a solo diver for safety. I am aware of the solo diver class and I plan to take it in the summer if I can find someone in Chicago who will offer it (hint!).

For the system you refer to, do you mean that I can just put the LP hose off my pony regulator to my BCD, rather than using my primary tank? Hmmm that is interesting because I can use my BCD combination octo/inflator hose to breath off of and I wouldn't need another second stage. I had not thought of doing that before, but it seems like a pretty good solution now that I think about it (if that is what you meant). Are there downsides to that setup? What other solutions should I consider?

 

[Cave Diver]

Thanks. Okay, it looks like I definitely underestimated my air supply needs as it seems I should be thinking of 2-4 times that volume. Does anyone know of a good simulator that will take into account pressure changes on ascent to determine what I realistically need for the emergency air supply?

Might I suggest the following article to you?

Rock Bottom and Gas Management for Recreational Divers | Spherical Chicken

 

[*dave*]

Thanks. Okay, it looks like I definitely underestimated my air supply needs as it seems I should be thinking of 2-4 times that volume. Does anyone know of a good simulator that will take into account pressure changes on ascent to determine what I realistically need for the emergency air supply? I know I could probably figure it out with moore's law and all, but its been a long time since my chemistry class in college, and to be honest that was not my best subject :shocked2: What I want to do is assume worst case (for me) of starting at 130 feet and ascending at the maximum safe ascent rate (which I know varies by depth). The calculation seems fairly complicated. I had assumed 30/fpm, which means I am at the surface in a little over 4 minutes if I lose my main tank at 130 feet. Naively I guess, it seemed like a 6 cubic foot tank would give me 4 minutes by the simple (and probably wrong) math that an 80 gives me an hour.. but I am not taking partial pressure and all that into account so I am totally open to reconsidering this, I still have plenty of time to get a bigger tank before my next dive in April. I am a pretty calm diver, I have been in emergencies and do not panic (myself anyway, can't say that for my buddies lol).

You'll need to know what your RMV is, to start. Let's assume it's .5 CFM. At 130, you are at 5ATA, so your consumption at that depth is 2.5CFM, assuming you are as relaxed at depth as you were when you determined your SCR to be .5. If something renders your primary gas supply unusable, there is a high likelihood that this will excite you to the point that your rate of consumption will double. Figure you'll burn 5CFM at that point. How's that 3CF looking, now?

Passing off a pony or a SA to an OOA diver who doesn't have enough experience to plan and execute a dive would likely present more hazard than doing an OOA ascent as you were taught during OW class. If they are ignorant enough to go OOA, I wouldn't be surprised if they were over weighted and had poor or non existent ascent skills, not to mention a SCR that is likely higher than 1CFM. You pass them 3CF of gas at 130' and you likely have just set them up for a second OOA. Do the math: 1CFM RMV=2CFM when stressed. 2 CFM*5ATA=10CFM. From 130, you're looking at 4:20 to reach the surface with a gas supply that will last about 20 seconds.

Moore's law? Great for figuring out MIPS and scale, but has nothing whatsoever to do with diving. I'd recommend getting educated on gas consumption before contemplating adding gear. I fear the only thing you will get from following the path you are on is a false sense of security.