IOA is the wetter park. USF has a water play area but you can take off your shoes before going in.
On Popeye, it's a good idea to take off your shoes and put them in the middle compartment. You have to wear them into the ride, but once there, you should be able to put them away. If not, then hold your feet up, because getting your shoes and socks soaked will make your feet waterlogged later in the day.