I got certified for open water diving through Scuba Monkey at Manatee Springs. Dove there for 3 days, also pretty much every spring and coastal reef are great dives. Just drive straight to Florida and you'll never run out of options.
This was a camping trip to Manatee, didn't dive this day as just wanted to paddle with my lady. (Dive instructor didn't want us to take pictures during lessons so no dive shots but it's a beautiful sight)
Manatee, Gators and turtles abound.
The full hook-up camp sites are pretty sweet too.