BCD wouldn't let air out

[Bob DBF]

...are you referring to taking three breaths off the REGULATOR while monitoring the SPG prior to entry? This is a critical last check to insure the tank valve is open, functional and pressure is stable.

I do the check myself and recommend it to others, however it does not insure the valve is completely open. Depending on the valve, 1/4 turn open may pass the check, a bit more it will pass for sure. So if the SPG starts bouncing as you descend, have your buddy open it.

Oh yeah, I learned 3 quick deep breaths. The idea is to test the flow, if the air flow is restricted by the valve, the pressure will drop.

 

[Esprise Me]

The one time my valve wasn't all the way open, the second quick breath caught it--I saw the needle move. Not saying it'll always work, but I'll always do it.

 

[ScubaWithTurk]

I have not read more then the first two pages but my first take is it is all due to a failure I see often.

Divers tend to neglect the buoyancy check when doing their pre-dive or buddy checks. Even if they check to see it inflates when they push the button, I often see them forget to check that all dumps are working correctly and that they can orally inflate.

These checks are something I speak about extensively when I am teaching an OWC and also when I see new divers on the boat who are about to bankroll in and have not fully checked their buoyancy compensator.