If compass on the right can cause interference, why are there instructors that mount the compass to their DPV? I would think that would cause interference as well.
It's a good point. I'm telling you what he literally wrote. I'm not telling you he was right, or that the logic still applies with respect to modern scooters.
Truth be known, it could have been a gut feeling or maybe he had a "noisy" scooter. Remember, this whole thing emerged in the mid 90's and some things have changed since then. Maybe scooters have better shielding now? Dunno...
If DPV interference does occur, I completely understand the reasoning ... but since DPV dives are a small % of overall diving, it seems silly to not have compass on the right arm as standard configuration, and just prescribe switching to the left for DPV.
Well... in an airplane you wouldn't change the location of the artificial horizon depending on whether or not it was raining outside and for the same reason (absolute familiarity) instruments always go where they go. No exceptions. This actually makes some sense regardless of whether or not you agree with the location of the compass or the reasons they give for it.
The one thing you need to understand about the DIR config is that standardization *is* a big deal in DIR. If you adopt the system, what you need to know is where the compass goes. Period. It doesn't even really matter why. It just goes there.
Creating a configuration that can work for every type of diving is a great ideal, but we already make significant changes such as tank size depending on the type of dive it is, so why should compass placement be any different?
Singles vs doubles is a lot bigger of a difference than switching your compass to the left arm when you go on a DPV dive, imo. Plus if DIR instructors are mounting compasses to their scooters, that really invalidates the entire standardization idea.
You kind of wrote those like it was meant to be one thought, but I see it as two.
The first thing you seem to be saying is something along the lines of, "why should it matter how I configure my gear" and the second thought is, "some instructors aren't standardizing, so why should I".
Let me start with the 2nd bit. There may be, over time, good reasons to re-configure. In theory (practice may be another thing) if the DIR configuration is changed, then it should be changed for everyone, all at once. This information should be propagated to the community by GUE instructors and nobody else. So in terms of "where the compass goes", all I can really tell you is what is written. Your GUE instructor will tell you if this is still the standard place for it, or if there has been a change over time. (things can change, books don't, and I'm not a GUE instructor).
On the first bit, DIR divers, for better or for worse, take standardization seriously. Jablonski cites "efficiency" and "safety" as the underlying reasons for complete standardization. It's true that the sky will not fall if you put the compass on the other side, but strictly speaking, it's no longer a DIR configuration if you do. All hard-core DIR divers accept the the need for absolute standardization as a fundamental underpinning of the system. This is something that you need to either accept or not. Many people do not. All DIR divers do.
R..
