cool_hardware52
Contributor
GDI:I dive a Zeagle dual bladder system with dual inflators and dual dumps. They have two models. Big Bertha (dual 65lb) and Little Bertha (dual 55lb). I have no problem with drag or streamlining and lets just say I have had a few cylinders on my person during some dives
Without engaging in debate about redundant bladders, I believe the original question concerned multiple OPV's on a single bladder. This is not necessary.
If you have redundant bladders each will need it's own OPV.
Tobin