When I asked this question a few years ago, people mentioned Sebastian Inlet. We intend to try that out this March. This is from the Florida State Park site:
FISHING MUSEUM TALKS
Fishing Museum talks are on Thursdays at 1:00 p.m. Join a Park Ranger for an informative interpretive program at the Sebastian Fishing Museum on Thursdays, at 1:00 p.m. Some of the topics covered are sea turtles, manatees, Florida snakes, land crabs, history of Sebastian Inlet, sea beaning, flounder fishing, snook & redfish fishing, pompano fishing, surf fishing, fishing though the seasons, how to smoke fish and how to garden for Florida's butterflies. Interactive recreational interpretive program topics include, how to make and throw a castnet, barrier island plant identification walk, a leisurely stroll along side of Sebastian Inlet, bird watching, beach walk and canoe/kayak tours. For information on upcoming programs call (321) 984-4852 or (772) 589-9659. The Fishing Museum interpretive programs are not held on holidays or in June and July. NO PETS.
Call (321) 984-4852 for more details.
Also, we went to the Harborside Oceanographin Instititue in Ft. Pierce and saw manatees in the inlet there.
Bobbi