ElectricZombie once bubbled...
Sure, here's why.
You have to remember that AirIIs and the like, are typically purchased by beginning divers or those who probably don't dive regularly. They probably do not practice enough, and are not proficient with basic skills.
You are kidding. This is the same as with any Air Source, I teach my students skills with both alternate Octopus and Air2's as any good instructor would. It is up to the Diver to have the nessasary skills to use the equipment they have purchased and to seek additional training for it.
During an out of air emergency, the donor donates from his mouth and switches to his AirII. Now, the donor has his reg/inflator/deflator in his mouth. During the ascent, the donor must constantly struggle to release air from the combo reg/inflator in his mouth. Some will take the AirII out of their mouth, vent the air and return it to their mouth. This is fine but remember, these are divers who don't dive or practice a whole lot. Most would not be comfortable taking the reg out of their mouths which will make venting the excess air harder. You now have the potential for an uncontrolled ascent or a lung overexpansion injury if a diver hold his breath while venting. The AirII just adds to task loading in divers who are not prepared to handle the added stress.
Vent/Dump the Air from the opposite shoulder dump, all good BCD's have two shoulder dumps not just one. You should never need to add air to the BCD while accending, you should practice OOA problems often so if and when the time comes you will be ready for it.
We used to have AirIIs here at the University until we complained enough to get at least a regular octo. We would notice the problem that I described, plus a few others. Many times, the students would go for the AirII and accidentally grab the flexable snorkel tube instead. The corrugated hose on the AirII is not very comfortable and wants to pull the reg out of your mouth. The AirII is not the best breather either. It will get you from point A to point B but, it feels like you are breathing through a straw. A basic low end backup reg will out perform an AirII anyday.
Having breathed from a Scuba Pro Air2 at 160Ft to the surface I found it delivered more than enough air in the OOA situation. I have never seen a problem with students or certified divers grabbing the wrong hose when going for an Air2, again this is a training issue, like any equipment, if you are not trained to use the kit, then you should not be diving with it.
Overall, the AirII creates more problems than it solves. Remember, you need to keep it simple, especially for new divers. It increases chance for injury and does not perform very well.
As long as proper training has taken place with the equipment it presents no more problems than any other sort of Second stage device
The bungied backup seems to be the best solution in my experience and is what I recommend.
For Technical and extended range Diving I would, agree however in recreational Diving the Air2 is a great way to reduce a hose from your First Stage.
I'm not anti-AirII just because it's not DIR, but because they do not seem to be the most logical and safe option. This is just my conclusion based on my experience.
IMHO
After approx 800 Dives with an Air 2 @ Recreational depths
Approx 200 OOA training exercises
and three real OOA scenarios
I have no issues with the ScubaPro Air2 it functions very well at recreational depths, provided correct training and buddy preparation, it has proven in my experience no more task loading then a Bungy rig or traditional Octo placement
