Compass on Left hand, Computer on right..

[Thalassamania]

I can swing about 14 lbs on my lungs comfortable, makes this sort of thing a lot easier.

You're right, with smaller lungs, 15 lbs of gas riding on your suit bubble would be at the least uncomfortable, and at the worst downright dangerous since you'd have to be diving with your overpressure valve clamped shut.

 

[Rainer]

In any case, your point holds, not really a huge deal where you place the compass or BT, but it's important for newer divers to recognize there are pros and cons to these various choices both for the diving they are doing now and the diving they might be doing in the future.

 

[Thalassamania]

You hit on the key there. Often there are one or more over-riding needs (in my case it is the ability to swim a defined and reproducible transect) that "force" a bunch of other decisions into a given form. All divers need to thing about what those sorts of forcing functions commit them to.

 

[TSandM]

Yes, no way I'm compensating for thirds in cave-filled double 95s with my breath! And in caves, you don't want much air in your suit, either -- it turns around and bites you if the cave heads seriously downhill (and they do!) You may never find a good spot to lower your feet to get that annoying air out of them again.

Recreational, single-tank diving, I use the suit almost 100% for buoyancy these days, and venting is a matter of lifting my left arm a very small amount. So I could have my depth gauge on my left, but why would I want to change? I like the DIR idea of setting everything up in the beginning so that you will never have to change it as your diving changes.

 

[Thalassamania]

I agree that setting everything up to start and changing as little as possible from dive to dive is an excellent plan. My only caveat is that the decisions should be made on each diver's needs rather than by projection of the instructor's needs. In the case of scientific diving, navigation and transect running are so critical that they clearly define a lot of decisions.

That's one of the reasons I love my Citizens watch, the depth alarm means that I can run a depth transect on the beeps and concentrate on time for distance and compass for direction.

 

[Rainer]

I don't disagree that different dive requirements might necessitate wanting different gear configurations.

In the case of precise transects, having depth on the left wrist sounds useful (you could of course also keep a spare BT on the right wrist if you felt that desirable). That said, how convenient is the left wrist for such navigation decisions? I know for Reef Check (wife was recently certified), they also keep a compass on their survey slates. I believe many cave divers do the same when surveying. That is, in such cases, placing the compass directly in front of the diver at all times is desirable.

In any case, I've been quite happy with the compass on my left wrist. We've done ~1 mile scooter rides away from shore (open water, complex navigation) only to end up right back where we started (so two miles round trip), so it seems to be working for us. That said, wife just added a compass mount to her scooter this past weekend, which looks like it might be the way to go.

I agree that setting everything up to start and changing as little as possible from dive to dive is an excellent plan. My only caveat is that the decisions should be made on each diver's needs rather than by projection of the instructor's needs. In the case of scientific diving, navigation and transect running are so critical that they clearly define a lot of decisions.

That's one of the reasons I love my Citizens watch, the depth alarm means that I can run a depth transect on the beeps and concentrate on time for distance and compass for direction.

 

[Thalassamania]

I have a compass and depth gauge mounted on my Farallon Mk-6, makes life much easier and assures that the line of travel and the lubber line are the same.

If your carrying a slate for data, it is really nice to have two grips, one the left and one on the right edge and a compass up top in the center; but often I've go my hand full of other stuff and then I find (for me) that I like my gauges on my left so my "strong" right hand is free and mobile.