I saw some completely overweighted ("I need at least 18 lbs.") maniac try to stop himself from crashing into some hard coral, and since he didn't understand that diving is done in three dimensions and on three axes, he proceeded to break off 4 coral heads and smash some fans for good measure with his tank; then, he swish-swashed around the other way taking out the hard corals he was trying to avoid in the first place, finally crashing FACE FIRST into a big old fire coral patch...he didn't touch anything with his hands though (hahaa). I winced and almost spit my regulator at that point from sheer hilarity (although you're not happy about what you are seeing, what are you going to do?). That guy's face was absolutely bloody when he finally came up, and I told him that "getting some people to pee on on his face" might help...he replies: "I've heard of that."