I shall henceforth keep my distance from divers sporting a prosthetic derrière...Years ago, I watched a video on YouTube where someone rubbed a plastic bottom (I think this was around 150 feet deep, and overseas - not Florida or the Caribbean) - a decent sized shark (maybe 5 or 6 feet long?) came from behind, reaching around and appeared to intend to bite. I didn't hear of any injury, but this happened fast, and was worrisome to watch.