Strobing
Well I must admit that I flash. An old habit to see and be seen. I used to do it on helicopters too, but that was more of a strobe effect due to the vibrations. The point Fluke made about chat on 121.5 is far more annoying, and far more serious than the occasional 'good evening' light beams.
Perhaps one day when the person that is asking for a position report relay on an emergency channel will be down there in a dinghy using his last fading transmission, to be then stepped on by some @rsehole.
P.S. I am not a badge holding member of the Guard Police, but I feel like joining sometimes.