This reg did have a venturi adjustment, and the point I was trying (poorly) to make was at either extreme, it was still doing this. And to clarify, it wasn't freeflowing, it was just giving me a hair more air than I was drawing. For example, if I drew REALLY hard (which I did once or twice to see what was going on), I'd get even more. If I drew very gently, I got less, but regardless, there was a slight impression of positive pressure. I have heard from some other divers that around 60' or so, it can be harder to draw air, so maybe this is by design? I get the impression from reading that this reg (again, Zeagle ZX-2 or something) is a "high performance" reg, so perhaps it's supposed to do that. I thought that using my tongue to reduce the airflow was appropriate and effective.
BTW, my instructor did tell me about the adjustment, and when I asked about the airflow issues between dives, he suggested that the cranking down the switch might help -- that's why I later adjusted it at depth (I couldn't find the switch so I removed it from my mouth, found the switch, cranked it down, and replaced it).
This is the same regulator I used in the pool sessions, and it wasn't doing this in the pool. I didn't notice it until I was aroound 50'-55'.
Could I have knocked it out of adjustment by having it in my dive bag and getting it bumped around? I tried to protect it by wrapping my wetsuit around it somewhat, but it may have gotten squished or jarred.
...or is it more likely that it just wasn't adjusted for depth?
