Our daughter and husband drove down to Fort Myers from Rotonda West today and were delighted to see several manatees.
From Junction 141, on the I75 just north of Fort Myers, turn east onto Palm Beach Boulevard. Apparently there is a sign for Manatee spotting boat trips but they said they drove about a mile, parked in the Lee County Manatee Park (75 cents)and were rewarded by seeing lots of Manatees from the bank of the river.
During the cold weather they are coming up river seeking the warmer water coming from the power station on the river.
I think the Manatees return back down the river in the afternoon - they were the between 11am and noon.