In some areas in Galveston Bay you can "beach" a Hobie Cat by sailing up to the "islands" next to the ship channel. Then as the ships pass they displace all the water. Suddenly you are looking out over several 100 yards of sand as the water gets sucked away from where you are standing (make sure you hold on to your sail boat). The water does come back though and that can get interesting.
I've heard about the wake surfers but I've never seen them. Looks like fun.
After reading this I would not be surprised to see the "personal watercraft" types with the SeaDoos, etc. start jumping these wakes after they read this. If they are not already. Some of those guys are real crazy.