Canoe the Hillsborough River
Probably the best kept secret in Tampa Bay. There are a handful of places to rent a canoe but the one we use is Canoe Escape. Take the two hour leisurely paddling trip and you'll see an amazing array of alligators, birds, turtles, and amazing plant life and landscapes. The river runs very slowly so this isn't strenuous. Plan on the whole adventure taking 3 1/2 hours from the time you park at Canoe Escape to the time you get dropped back off at your car. There is a lot of tree canopy so sunscreen is recommended but not critical. If you go when sun is out, gators will be on the shoreline. They won't bother you if you don't bother them.
canoe escape website here