So, other than OW buddie diving, we are in complete agreement. There is NO student training on signalling to their instructor they are in trouble. This isn't in any training manual, isn't taught, and is an issue that all respondants can not document whatsoever. Students are NOT taught how to signal if they need help, nor is this part of any training syllubus. And no one here can find any documentation otherwise.
(This is NOT the same as ending a dive, for any reason.)
(And reffering to nebulus hand signals that could be subject to wide interpertation, dosen't cut it either.)
No, not at all. You’re being quite obtuse here, if not downright trolling.
Students are given multiple hand signals to communicate with. While some can be a little vague the intent is to signal that something is wrong and they either need time, help, or to go to the surface.
As has been previously discussed, you don’t need to tell someone “if you need help, ask for it”, none the less all but the most incompetent instructors will make sure that point comes across.
So no, I don’t agree with your conclusion at all. Sorry the evidence doesn’t satisfy your (non-realistic) opinion, but that’s a you problem, not an us problem.