Air2 plus safe second

[Standingbear56]

The instructor also could also have a 2nd safe second so that s/he can teach or familiarize students with different air sharing methods. As a regular sport diver however, as long as you are comfortable with it and know how to use your Air II properly (ie donate your promary, NOT the Air II) there is no need for you to have an additional safe second. I have however seen people with an Air II style Alternate Air Source AND a Spare Air. Hmmm, wonder what kind of looks I'd get if I ever hooked up DA Aquamaster's bandoleer set up and went on a tech dive????? The photos would be priceless!
George
PADI MSDT 33859
Prime Scuba

 

[24940]

To be fair, your basic math should be applied to both ways.

Based on your math,

Air 2 removes one additional hose. It must be less failure point.
Air 2 is an integrated design, so it adds a failure point.

So, it is even.... Am I right?

Not in the context of this thread. The OP is asking about using an AIRII and a secondary. It's a risk vs benefit debate. Adding a third reg might be useful if you had to share air between three people, but I don't know anyone gas planning for that scenario. I've yet to be mugged by an OOA diver, much less two. As an instructor, I'd be pretty worthless to allow a student to go OOA or even close to reserves on checkouts.

I thought we agreed that the proper training is a "must" on any gear configuration in the previous posts. So, the button confusion can't be a problem factor on Air 2 users after being taught and practiced properly. A diver must know their gear.

Ideally, I agree. Realistically, that's not been my observation. I watched a certified diver trying to dump air by pushing the purge button on his AIRII last month. Granted, that's a diver problem, but given the nature of the incident the device is designed to accommodate, how many divers do you feel are adequately prepared to handle an OOA in a relaxed, thoughtful manner?

You are using the same reg for the primary and second? I am using the different regs for the primary and second. My seconds including Air2 aren't different with my primary ones that much, specially in the rec. range. I can breathe my Air 2 at 130ft without any issue... I can breathe my back up (R190 and R380) on my double sets without any issue as well. Actually, some agency recommends this NON-balanced 2nd stage as a back up because they believe that it is less failure point and easy to fix in UW. So, if you believe that Air2 is in the same league with the entry level stages like R190 and R380, do I choose a wrong back up?

Yep, ATX200 primary and secondary. I wouldn't place the AIRII in the same class in terms of breathing. In terms of ergonomics, I find a standard inflator more intuitive. I've used my AIRII at depth and survived, but I wouldn't want to deal with it in an actual OOA.

Just to be clear, you aren't really endorsing the configuration the OP is referencing, are you? Two secondaries and an AIRII?

 

[DA Aquamaster]

Thought I recognized you.

It's basic math. Virtually every piece of gear is a potential failure point. Add another reg, another hose, another.... and you are adding another potential failure point.

Many of the AIRII type combos I've seen (Including the one I own) have the inflate and deflate on opposite sides and in direct alignment. I've seen more than a few divers depressing both at the same time.

I use the same reg for my secondary as I do for my primary. I'm not going to bother pulling up specs on one vs the other, but I don't think you will argue the AIRII breathes as easy as a high performance second stage.

The bold portion of your statement is not limited to the context of this thread. Many inflators have the buttons in line and on the same side - it does not take a diver long to figure out and remember which is which. So the button placement on integrated octo/inflators has no real bearing on anything.

In fact I'd argue you could make a case the other way. One of the most common generic inflators has the buttons on the side and on the end giving it perhaps a slight advantage training wise over the first couple dives, but their shrader valve mechanisms are much more failure prone and being unbalanced they make very precise additions of air more difficult.

An Air 2 does eliminate one hose that can leak as well as one dynamic o-ring on the octo's inlet fitting. The Air 2 combines an inflator (no more complex than a non integrated inflator) and what amounts to an R190 second stage (no more complex than any unbalanced Octo). So in the end, it is less complex with fewer failure points.

In the extreme, if you also dive with an octo, all you have added in comparision to an inflator is a very simple lever, poppet and seat for the second stage portion of the Air 2.

The only reliability argument that can be made is that if your Air 2 fails open and freeflows, you have to disconnect it which leaves you with no low pressure inflator. Of course you still have the manual inflate capability and/or a dry suit. On the other hand, if your octo freeflows, you are pretty well screwed unless you have doubles and can turn off the post with the freeflowing reg.

At worst it is a wash and at best the advantage is with the Air 2. If for example you shoot a lift bag with an Air 2 and it "freeze flows" in very cold water, you disconnect it for 15-20 seconds to let it thaw, reconnect it and continue the dive. If you do the same with an octo or second stage, you can't disconnect it and you are again screwed unless you have redundant doubles.

So in effect, an Air 2 offers substantial advantages in terms of reduced failure points.

 

[24940]

So in effect, an Air 2 offers substantial advantages in terms of reduced failure points.

Primary Second=potential failure point, but the benefits are rather apparent.
Secondary Second (Including AIRII)=potential failure point, but the benefits are rather apparent.
Third Second =potential failure point with what benefit?

Adding a third second stage adds a failure point that would not exist with two second stages..

 

[Hoosier]

Not in the context of this thread. The OP is asking about using an AIRII and a secondary. It's a risk vs benefit debate. Adding a third reg might be useful if you had to share air between three people, but I don't know anyone gas planning for that scenario. I've yet to be mugged by an OOA diver, much less two. As an instructor, I'd be pretty worthless to allow a student to go OOA or even close to reserves on checkouts.

NO..... Please look at my initial post in this thread. I used your phrase ONLY on Air2.

Ideally, I agree. Realistically, that's not been my observation. I watched a certified diver trying to dump air by pushing the purge button on his AIRII last month. Granted, that's a diver problem, but given the nature of the incident the device is designed to accommodate, how many divers do you feel are adequately prepared to handle an OOA in a relaxed, thoughtful manner?

It is a contradictory argument. We have already agreed on the pre-requisite proper training on any gear configuration?

If not, why an entry level tech divers keep practicing the basic 5 drills? Nothing is different with the rec. divers. Proper training and practicing.....

Yep, ATX200 primary and secondary. I wouldn't place the AIRII in the same class in terms of breathing. In terms of ergonomics, I find a standard inflator more intuitive. I've used my AIRII at depth and survived, but I wouldn't want to deal with it in an actual OOA.

Like I addressed, it is a debatable opinion and your preference. I am using ATX100 primay and second. MK25AF/G250HP +R190, and MK17/G250HP + R380 for the double and MK25AF/S600 + Air2 for the single. I can't notice any difference.

Again, I haven't seen and read any accident report on Air2 except a serious inflator failure on the tech oriented wings (I also have it).

Just to be clear, you aren't really endorsing the configuration the OP is referencing, are you? Two secondaries and an AIRII?

NO.. same as above.



I am NOT trying to change your preference and gear configuration here. (Who cares whatever you are using). But, from your initial post, I am just trying to make clear that there is nothing wrong with Air2 based on the technical, scientific, and legitimate facts instead someone tells it.

Just my 2 bar.

 

[24940]

We both know where this debate leads.

I own an AIRII and used it for over a year. I've evaluated both configs by diving them and have found the AIRII to be wanting in some aspects.

FACT:There is not an AIRII type inflator made that breathes as well as my ATX200.
FACT: Using an AIRII as a regulator causes more stress on the jaw than a standard secondary.
FACT: It is easier to control buoyancy with the inflator in you hand than it is in your mouth.
FACT: Placing inflate/deflate buttons on opposite sides and in alignment requires greater care to insure both buttons are not simultaneously pressed than a standard inflator with dump on the top and fill on the side. Ergonomically, it makes no sense.

It's personal choice as to whether or not we consider the benefit of losing a single hose is worth disregarding those facts. If they aren't considered important factors by you, that's fine. They were for me.

I teach both to my students and they can choose which they would prefer to dive.

OMG, I'm in a AIRII vs Octo debate.

DA, thanks for your input here. I'd like to respond to your points with a few counters, but I need to take a breather. Care to join me in a spare air thread?

 

[RJP]

This thread has become a parody of itself!

- Debating the trade-offs between the number of failure points in a "second secondary" vs a "third secondary"

- Suggestions that a redundant Air2 + octo combo might only be useful "for a solo diver diving doubles?"

 

[24940]

Well, it may be a parody of itself, but it made a believer out me. I'm replacing my primary and secondary with AIRIIs.

 

[scubastaci]

Thank you for all of your........input. I guess what I was looking for was a "no, not really necessary" or a "sure, what could it hurt" kinda response. I can say without a doubt (since we are practicing OOA's in class) that my Air2 is a little harder to get air out of than my Primary, but as long as I can breath and slowly make my way to the surface, it will be fine!
Since my hubbie and I are the only one's in class that have the air2, we are practicing the give your primary scenario. We will be buddying up with other members of our class so they too can understand what to do when they encounter someone who has an air2 as their second. As far as inflating the bc, we had to do that both ways. As the diver OOA I had to manually inflate my vest while on his primary and vise versa. I had no problems inflating my BC while on my air2. Biggest problem I had on the OOA practice is that my husbands mouthpeice is bigger than mine, so it took a little longer to put back in while manually inflating my BC.

 

[24940]

no, not really necessary...


Welcome to SB, btw.