SeaJay
Contributor
Blue Space once bubbled...
Not true mine has a bottom dump and so does my buddies which is last years model.
I'm sorry... I was unclear on that one.
The Balance has ONE bottom dump... On the right hand side, if I recall. The Black Diamond has two... One on each side.
I personally prefer one to two... But only if the wing is of the "O" design. With a "U" shaped design, having only one bottom dump means that if you are horizontal or inverted and go to dump, you can only dump the air from one of the wings... You have to go vertical to get the rest of the air out. Having a dump on each wing (like the Black Diamond) enables you to dump from both sides of the wing and more effectively get all of the air out.
...Which is why I personally prefer an "O" shaped wing... Because I only have to have one bottom dump, yet I can still get all of the air out of just one side.
This is especially useful if your hands are full of lights, reels, artifacts, or whatever (handling your buddy's OOA?) and you only have one hand to spare.
Speaking of bottom dumps, I have found the Halcyon bottom dump to be of particular great design... Unlike most BC's, their singles wing is of an "O" shaped design (as is the Scubapro Knighthawk, come to think of it)... And with only one bottom dump on the LEFT side... Opposite of most BC's. Why the left side? Well... Because an OOA is handled almost exclusively with the right hand... So it's the left hand that's available. It also allows you to control both your inflation and deflation (no matter whether you use the top or bottom dump) with only one hand... The left one.
...Which is why people are recommending having your gauges on your right wrist... So that during your ascent, you can be simultaneously dumping (or adding), and looking at your gauges, no matter what position you are in.
That's what the DIR guys are calling a "holistic" system... And that's why they are saying that it's "all or nothing" and that it's a bad idea to "pick and choose." One thing sorta leads to another, and it's the whole system that supports itself, not just a few individual items.
...But I am not plugging DIR... And I am not saying that anyone should dive any certain way. I'm simply pointing out that train of thought and why those guys dive like they do.
...And why I chose the BC that I chose.
YMMV.