My stepfather had a house on Lake SantaFe near Gainesville, FL when I was in HS (20+ years ago). I used to go out to the lake and swim all the time. Viz was a murky brown 10-15 feet, I guess. And, there were definitely alligators in the water, I'm sure. However, I never saw them.
However, the alligator population in Florida has increased over those 20+ years. I don't think I'd go take a swim in low-viz water anymore.
Springs, spring-fed rivers (Ginnie, Rainbow River) yes - I would, and have dived in those - just a few weeks ago at Rainbow River. Saw turtles, etc.... but didn't see Alligators.
Today happens to be the start of a 5 week Alligator hunting season down here. They started issuing a limited number of permits to help control populations.
The attached photo was taken by my uncle who lives on Lake Seminole (near the FL/GA border in GA). This was sunning itself in his back yard.....
I'd much rather dive with sharks.
Anyone else?