Well, to drift the thread, my student, who was the owner of the plane, and a licensed PPL, while landing on the water under my supervision, made a handling error, which I could not correct in time. We both went out through the windshield, as the plane went over in the water. I did not undo my seatbelt, I ripped it out of the plane instead. Were we not wearing lifejackets at the time we were thrown into the lake, I. for certain, and possibly he too, would have drowned. I insist now, as I did for all my previous flights, including that one, that all occupants wear a lifejacket for overwater flights, or flights for which a water landing is intended. It would not be possible to retrieve and don a lifejacket from a sinking plane - if you're not wearing it when you exit, you're without it. If you're injured in the collision with the water, you might not be able to keep yourself afloat. .