|It's not really a "hole"|
So when I lived in Florida, I spent a fair amount of time snorkeling in the river, and this was the prime location. The rocks and seaweed among an otherwise bare sandy bottom hosted numerous species of crabs, shrimp, and small fish, the barnacles would attract puffers and burrfish, the shallows would allow frequent sightings of stingrays and cownose rays, and the deeper sections were the realm of the dolphins and manatees. The docks visible in the background also provided their own opportunities. While not exactly a "swimming hole," it was one-stop shopping for an amateur naturalist.
Those rocks had to be treated with respect, though. The barnacles and oysters all over everything, easily visible here, are as sharp as glass, and most trips garnered at least one cut (I still have a scar on my ankle from an oyster.) Overall though, it was a pretty neat area for a little roadside spot off the Eau Gallie Causeway.
This is a composite of two images, part of a 180° panoramic project. And I'm assuming you didn't miss the heron back there...