This is a bit harder to get to get to, but there is a boat ride that leaves from Hubbards Marina, which is linked below.
This is very close to the Bellwether and provides great access to Ft. DeSoto State Park using a ferry. They also have sunset cruises (free beer and wine included), dolphin watching, and snorkeling.
The Sirata offers Jet skis and hang gliding. It also is located right nextdoor from the Bellwether.
Tradewinds has a large waterslide that you can buy a day pass for. The waterslide is two doors down and is visible from the Bellwether.