I was walking into Uncle Bill's boathouse, and Mother was there.  She said "Shhh-you'll scare him away."  She was trying to catch a fish.  When I looked down, I saw it turn and swim slowly away.  It was huge and black-about 2 or 3 feet long.  It swam right between the open jaws of an alligator, which did nothing.  As I walked along the edge around the inside of the boathouse, I saw that there were two or three great crabs in the water-all about 12-15 feet wide, not counting their long, wavy arms.  It was very unnerving.  I thought no one would believe me.  They were just like monsters in a horror movie.