I know what I would do if I saw them screwing with my stuff......and there wouldn't be any cutesy tricks involved.....it would, however, be a close encounter of the most unpleasant variety. Sound carries a long, long way on the water, and there would be plenty to listen to and no doubt as to what was going on. I'm sure that would end any desires by the offenders to try it again. (I'm not a strong advocate of tact. After all, you catch more flies with sugar than with vinegar....but who the Hell wants flies?)