Still, no one answers the question - absent ANY other indicators, what would lead a rational person, be they rescue or otherwise, assume a diver is in distress just because his mask is on the forehead?
I am very safety concious and have vast experience in safety, emergency activities, have actually rescued persons and even been recognized for life saving. Before getting into scuba I snorkled for decades and never heard of this mask thing, nor would I ever think a diver/snorkler is distressed, or in danger, just because the mask is on the head. I think someone came up with this a long time ago and we may just be stuck with it. But I am still going to do it...........