To the OP: You have had a very good insight. One of the challenges of diving with a variety of buddies is the lack of standardization of equipment and equipment configuration. It is very important to go over equipment before a dive, so that each diver knows how the other will share gas, dump weights, and CONTROL BUOYANCY. The last concept is often omitted. I learned it the hard way, trying to mentor someone and in the last effort to help him get neutral (in ten feet of water), grabbing his inflator and discovering that, instead of buttons, it had colored PLATES to control it. It was the weirdest thing I have ever seen, and I had no idea how it worked.
When we bought our original gear, my husband and I decided it was a good idea to get essentially the same equipment and configure it the same way, for this reason. (Long before I ever heard of DIR diving.) Since then, I have moved to diving with a whole GROUP of people who have made that decision, because I think it enhances safety. But if that is not possible for you, you just have to try to brief your buddies on your gear and how it works, and hope they can remember it in an emergency. As you found out in your class, what you are really doing is betting you never have one.
I don't like the Air2, which is what I started out with. I found it to breathe poorly and be very awkward to use, but I will admit that part of it was that I had a standard length hose on my primary regulator. Sharing gas on a 24" hose is uncomfortable. I recommend that anyone who is using an Air2 have a longer primary hose. There is a reason octopus hoses are generally 36" or 40".
When we bought our original gear, my husband and I decided it was a good idea to get essentially the same equipment and configure it the same way, for this reason. (Long before I ever heard of DIR diving.) Since then, I have moved to diving with a whole GROUP of people who have made that decision, because I think it enhances safety. But if that is not possible for you, you just have to try to brief your buddies on your gear and how it works, and hope they can remember it in an emergency. As you found out in your class, what you are really doing is betting you never have one.
I don't like the Air2, which is what I started out with. I found it to breathe poorly and be very awkward to use, but I will admit that part of it was that I had a standard length hose on my primary regulator. Sharing gas on a 24" hose is uncomfortable. I recommend that anyone who is using an Air2 have a longer primary hose. There is a reason octopus hoses are generally 36" or 40".