Regulator Performance when Vertical

[Kevrumbo]

I noticed in this thread help with my brand new Atomic B2 that the performance of a regulator while vertical in the water can be a concern. I like to pull up into a vertical position once in a while - better field of view, better situational awareness, and it gives my neck a break. Is this a first stage or second stage issue? And, are there certain designs or brands that are better when vertical than others or is it just tuning?

Thanks.

second stage isn't being assisted when vertical.

All regulators are impacted by diaphragm orientation. I.e. why they freeflow when you put them in the water mouthpiece up, and stop when you rotate them mouthpiece down.

Poseidon regulators are not impacted by orientation up or down, but are impacted by orientation side to side. You can be upside-down and they will breathe exactly like they do right-side up or anywhere in between. They will freeflow when the diaphragm is face down, and be a bit stiff when the diaphragm is up *roll side to side*

It has nothing to do with diaphragm orientation relative to the surface, it has to do with relative depth of diaphragm, mouthpiece, and diver's air canal. If the mouthpiece (and diver) are deeper than the diaphragm, it's harder to breathe.

. . .

No . . .it's neither a first stage or second stage regulator performance issue, but actually a immersion physiological effect of pressure differential and a negative static lung load while being vertical in the water column which can make work-of-breathing and ventilatory metabolic CO2 elimination difficult especially under heavy physical exertion, regardless of how well tuned or the highest performance breathing machine rating your reg may achieve.

Refer to this video to clearly see this phenomena:

(And go to 12:25 minute mark in the video below for a description of negative static lung load in the vertical trim position):

To reduce or eliminate negative Static Lung Load (SLL): Open Circuit divers should return to horizontal trim or a breathing position with head & upper body slightly tilted down (see fig D) past horizontal. . .

 

[scrane]

I noticed in this thread help with my brand new Atomic B2 that the performance of a regulator while vertical in the water can be a concern. I like to pull up into a vertical position once in a while - better field of view, better situational awareness, and it gives my neck a break. Is this a first stage or second stage issue? And, are there certain designs or brands that are better when vertical than others or is it just tuning?

Thanks.

I think it was pretty well established in that thread that the regulator was not functioning properly and needed service.

 

[tdallen]

Yes, but it was also presented in that thread as a general characteristic of some/all regulators which led to this post. That said, I'm still trying to parse my way through Static Lung Load which seems to indicate the issue is more a physiological reaction of the body then any mechanical attribute of regulators... The questions are simple but the answer never is, lol.