Get bumped by a manatee snorkling and you will sh!t yourself! They are huge, you are looking through a mask and you freak at first because you have no idea what this huge thing is next to you.
My buddy landed a 6 ft bull shark in the intracoastal waterway a few weeks back. He was anchored about 150 ft from the sandbar I take my kids to!
In salt water, EVERYTHING is swimming around you. At Peanut Island (just inside Palm Beach inlet) I have seen 3 ft barracuda sitting idle only inches from groups of people drinking beer in waist deep water.