Who thought I would have created such a lively topic. I think the responses generally go to my original point, most divers think it odd, some think it necessary, but no one seems to know how it started and why it is taught, in some circles, anyway. To repeat myself, there is no logic that, ABSENT any other indicators, one diver would assume another diver is in distress because the mask is on his forehead. Add to this that MOST of the time said diver/s is/are in a group just bobbin around enjoying the water.
Mask on forehead, much more comfortable and so easy to transition on or off with just one hand.
I agree that safety is paramount, but so is common sense............................