Want BCD that gives me same buoyancy at any pitch angle

[Nemrod]

Funny. I have never noticed a difference in the way my reg breaths in any position, at any rec depth. The 1st stage is an unbalanced piston and the 2nd stage is a Hollis 500SE. Inhale and exhale are both easy in any position. Maybe the difference is so small that it's hard to notice.

Funny I hear this all the time and again all regulators conform to the laws of physics including your Hollis and if you position yourself as shown in the graphic you will notice a difference and it it is measureable and I have measured it in years past. The variation is less noticeable overall with a sh reg vs a dh and servo/pneumatic amplified regs mask the variation but it is always present.

N

 

[phoenix31tt]

I have also noticed that, thanks for the diagram. I have an Abyss 22 as well and experience the same thing, I guess the second stage also causes a variation as well? It's more noticeable on my octo which is a Mares MV.

 

[Storker]

Back plate and wing.

Not necessarily.

I dive a BP/W. I love turning on my back in the middle of the water column, looking up at the surface, but I discovered quickly (to my chagrin) that turning around on my back made me significantly more negative. Especially in a WS, where all my buoyancy is in the wing. Kinda frustrating the first times: You hang there, perfectly neutral, turn around to look up and discover that you're sinking. Another argument for having most of your buoyancy in your DS and only offsetting the weight of your gas with the wing...

 

[The Chairman]

Not everyone notices the difference. That doesn't mean that the difference isn't there, just that they aren't sensitive to it.

 

[scottwilson1]

That's all it is: pressure differentials. The regulator gives air at the ambient pressure it's at. Prone, your chest is a couple of inches shallower. Supine, the chest is a couple of inches deeper. Most regs have a work of breathing around an inch. In other words, that four inch swing is huge when it comes to breathing.

thanks for the info NetDoc

 

[Nemrod]

I have also noticed that, thanks for the diagram. I have an Abyss 22 as well and experience the same thing, I guess the second stage also causes a variation as well? It's more noticeable on my octo which is a Mares MV.

It is the location of the center of the ambient (second stage) diaphragm in relation to the center of the lungs that causes the differences in breathing (cracking) effort between the diver positions shown in the diagram.

N

 

[Airburnr01]

If it was this tough to figure out, I wouldn't dive. Especially in a dry suit, in cold water, at depth, in the dark (more stress, faster breathing) etc,etc,etc. I would be bobbing like a cork. I have read thru 30 + posts and there is no help for stupid, ignorance can be educated out. I think these folks have valiantly tried to show you the light, and there is no help. Flounder on.

Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[Kharon]

Funny I hear this all the time and again all regulators conform to the laws of physics including your Hollis and if you position yourself as shown in the graphic you will notice a difference and it it is measureable and I have measured it in years past. The variation is less noticeable overall with a sh reg vs a dh and servo/pneumatic amplified regs mask the variation but it is always present.

N

I never said my regs didn't obey the laws of physics. Nor did I say there was no difference. What I did say was that I don't notice it and maybe it's too small for me to notice.

Many people claim that writing on a CD changes the music in a noticeable way. Maybe it does but I sure can't hear it. Maybe I'm much less sensitive than others or maybe the people that can discern these things are far more sensitive than I. That doesn't change the fact that I can't tell the difference.

And, please don't condescend or patronize and tell me to "just go try it". In fact I did 2 dives on Lake George yesterday and just for $hits and giggles I did try it. Guess what. I still can't tell the difference.