A regulator 2nd stage (the part you actually breathe through) delivers air at the same pressure as the water surrounding the 2nd stage. For it the breathe naturally and effortlessly the 2nd should be positioned at the same depth as the center of your lungs. If your lungs are lower than the 2nd, it will be delivering air at a pressure less than the pressure in your lungs, and you will have to work harder to draw it down, just as if you were using a long snorkle. If the pressure on the diaprha If your lungs are higher than the 2nd it will be delivering air at a higher pressure, and seem to be breathing exceptionally easy, or even "force feeding" you air. When you lift your head up to look up you raise it higher above your lungs, which increases the work of breathing.
This is, BTW, due to the immutable laws of physics and not the design of the regulator, so it hold true for every regulator made with this configuration, though it will seem more pronounced on a regulator that is already hard breathing, or delivers only a marginal amount of air - it's always amusing when people boast how their regs breathe absolutely the same in every position - it just doesn't work that way unless God has suspended the laws or nature for that marque. However, new or nervous divers tend to notice it more than more experienced divers, who have usually become so accustomed to the phenomenon that they don't even notice it anymore. The new Zeagle appears to be a very good reg, by the way, and should breathe as well in this respect as any other top reg. However the problem could be a sign that the shop didn't set up the regs right before deliver - new regs out of the box should always have a touch-up tune/check before being put into service. Or if your 2nds have an external adjuster it could be a sign you have it set too "tight".
QUOTE]Originally posted by MightyDiver
Is this normal to have a very hard time trying to draw air through your second stage when you look straight up at the surface? This is the only time it requires effort to draw a breath on my second stage. Happens every time though.
I am using a new Zeagle Flathead VI. My husband has the exact same model and he says it's tough for him, too. Doesn't matter if we're at 40' or 20' depth, still happens. [/QUOTE]