klausbh once bubbled...
Hi Mike,
I liked your post, respect your opinion, and strongly agree that we are talking about more than just a matter of equipment.
Here are a few of my thoughts in response to your post:
1. All else being equal, there is an advantage to having less pieces of gear. Combining a seperate watch and depth gauge to a single bottom timer is good. Combining a seperate line cutter and serrated blade to a single cutting instrument is good. You might not consider the tradeoffs of combining an inflator and a backup regulator worth it, but some do.
Of course simplification can be good. We need to think about what we want to simplify though. If the goal is to simplify and mistake proof emergency procedures, an apparent equipment simplification may or my not productive. I your examples combining cutting tool types simplifies a procedure because you only need to reach for "the knife". The same is true for the combination of depth gauge and timer.
2. Muscle memory is a real phenomenon, and it can be important. So is brain memory. It all comes down to training. When your inflator is in your mouth it's not on your shoulder. I'm sure you will agree that there are more difficult things to learn about SCUBA than that.
I agree. We always need to be able to reason. However, I think that having less things to do that require reasoning in an emergency is good. In an OOA situation there could be lots of things that require your attention. Do we ascent directly or go back to the line? Navigation? Do we have enough gas? Is this diver doin ok or are they about to panic? Ascent rate monitoring. Just some examples. I would rather not have to "think" about how to dump air. With the configuration I use, the only thing that's different in an OOA is that another diver has one of my second stages. Everything else is unchanged.
3. That divemaster might have been overweighted. I rarely even touch my inflator above 20 ft, because my bladder is virtually empty by then. Or was he positively buoyant the entire safety stop, staying down by clinging to the line?
You would have to know this DM but he wasn't over weighted and is one of the best recreational divers I've ever seen in the water. It was cold water though and he was wearing a heavy semi-dry wet suit and the other diver was in a two piece 7 mil. A lot of compression happens in the top 20 ft.
4. My procedure is to lift the inflator and dump. If I'm breathing from my AIR-2, that means taking it out of my mouth every now and then.
-Klaus
Shoulder dumps - hehehe - shoulder dumps - sigh.
Of course it can be done. By itself it isn't even tricky. It's just one more thing to have to practice and think about and it's one that we can eliminate.
IMO, if we're going to complicate a procedure, especially a critical one, there should be some real benefit. In this case I don't see one. As I said before this looks slick compared to an alternate on a sloppy long hose with the reg held to the diver by some little clip thingy that usually comes loose leaving the alternate to dangle but I don't like that solution either.
My solution is to just put my backup right under my chin on a hose just long enough to allow free movement of my head when using it.
Just looking at it from a systems engineering point of view, when ever we make a change we need to consider the impact on other parts of the system. Ideally, when we add something (equipment or procedure) the change is isolated and solves a problem or fills a need with zero effect on the rest of the system.
In this case you get rid of a hose. Now you need to change the ascent procedure. Now they add shoulder dumps. Now you have something else to think about and practice. It's a lot to go through to get rid of a hose that when sized well and routed well was never a problem. And all this assumes that the diver is going to practice using the device.
My bet is that most divers who use these things haven't practiced with them. I warn you though it's the bet is rigged. In almost 4 years of owning a dive shop I've argued this with many many people. Usually I get them with my first question which is..."Have you practiced with it?" They haven't and usually respond with "Oh, I never thought of that. I'll try it". This is a whole seperate issue, of course, but they're sold on the device to get rid of a hose (which is a pain the way they were taught to rig and carry it) and they assume they'll be able to use it when they need to.
The dive shop makes more by selling an air2 though than they do selling you a well sized hose and a piece of shock cord. LOL
