BE AWARE-- It is illegal to interfere with them in any way --do not touch, do not ride -- you may look, and film, and that is all. Please watch for the "Manatee Zone" speed limit signs - they're mammals, and need to breathe air just as you and I do.
Unless they've been harassed by someone, they're very docile and approachable. Normally they move slowly and deliberately, but their tails are immensely strong, and they *can* move fast if they want.
I was snorkeling in the ocean off Hollywood (Florida) Beach when I got that I'm-being-followed feeling and turned to look behind me. Out of the corner of my eye I saw part of a huge grey body behind me. Having recently watched 'Jaws' (again), naturally my first thought was
Turning on around, I found a large manatee behind me. We looked at each other for several minutes. Little tiny eyes, nostrils closed up, thin short back hair, green algae on the back, tiny minnows swimming above that huge back... an amazing few minutes. When the manatee left, very leisurely, the backwash from the tail was really something! After that encounter, and being of a rotund physiognomic persuasion myself, I feel that I have, in the parlance of my American Indian ancestors, been adopted as a spirit-brother of the manatee tribe. Hence my moniker.