planman:This question is simply out of interest from an international angle. In New Zealand a diver who surfaces and puts his/her mask on top of their head is considered "in distress". Is this the case in other parts of the world.
I'm glad you asked. From what I have seen, MOF begins as an unconcious reaction early on and is embedded into behavior if not corrected. I've heard more than a few instructors teach that MOF is a sign of distress or that it just makes you look like a dork. It doesn't matter to OW students when they get in the water and become task loaded with new skills and physical challenges.
It means nothing in the places I dive, but I'll check a diver if they go MOF. Usually just a look.