All good suggestions,
but it's still a little early for them to be at the power plants and up in the rivers and springs,
the reason I say that is because our Gulf water temperature is still in the upper 60's,
I have personally seen 5 manatees in the Gulf and Tampa bay waters within the last week,
I believe they are slowly eating their way toward their winter "shelters",
judging from the direction they were all traveling,
Manatee's are never in much of a hurry,
they'll continue their travel as long as the water temp allows.
I frequently see manatees always as a delight for the passengers on my charter boat, here are some pictures,
the first one was a young calf he stayed around my boat for more than 30 minutes
approaching snorkelers one by one, they are very affectionate
(it is illegal to harass or pursue them, but legal to pet them if they approach you)
the other two were having a "make out session" right next to my anchored boat (awesome)
then one beached himself and allowed my first mate and a couple of tourist to "scratch his back"
then rolled over so they could rub his belly (incredible)