Quote: (Originally Posted by
silent running)
My AP buddies all complain about the super tight stock OPVs and how they only activate by pulling on the dump cord, a design feature which may help facilitate pressure tests on the surface, but which certainly isn't convenient in the water, either during a slow ascent or even potentially injurious during a fast, emergency ascent. And why is the OPV nearer to the bottom of the CL? A great feature, if you dive upside down and like pulling on a string.
None of my 5 AP buddies used the OPV and vented through their noses or around their mouth seals, which I try to minimize as I don't like messing with my mask seal too much or letting any water into the loop through the DSV.
I am assuming that your "AP buddies" are actually opening their OPV after they have done their pressure test?
There have been cases of lung over expansion injuries due to people either forgetting to do so or not being aware that this step is necessary. The AP OPV works just fine, it just shouldn't be necessary for it to be triggered. A diver should EASILY be able to recognize when there is a pressure differential and vent gas out their lips or nose or both without the OPV ever releasing. The OPV is there for those "once in a blue moon" situations where due to task loading or some emergency the diver is not paying attention to things and the OPV releases gas to prevent injury.
Now if the diver is consciously venting gas out the OPV by pulling on the string, that's a different story. It works great, and the diver may choose that method instead of venting out his lips, or he may use both, but it works great. As long as they have the OPV open and not shut down, I really can't understand what their complaint about the AP OPV would be. I have never experienced a problem with it, nor have I ever heard anyone complain about it.