Well... not to open a MOF debate... but, from experience I can tell ya' that there ARE times when getting that mask off your face to make breathing easier... MUH (Mask Under Hood) just would not be good here...
... and then there's that "Cold water incursion" issue with MUH that others mention... WARM is good... that's why I wear a hood... when I wear a hood...
... and, finally... umm... weaseling a hood on over the top of a mask (... and I imagine it might also depend on what SIZE mask you're wearing...)... just seems wierdly uncomfortable...
... if you're worrried about loosing a mask... carry a spare... or put a bungie on it...
... and then there's that "Cold water incursion" issue with MUH that others mention... WARM is good... that's why I wear a hood... when I wear a hood...
... and, finally... umm... weaseling a hood on over the top of a mask (... and I imagine it might also depend on what SIZE mask you're wearing...)... just seems wierdly uncomfortable...
... if you're worrried about loosing a mask... carry a spare... or put a bungie on it...