Biology interest is based on both land and water creatures, especially birds and large freshwater fish. Week-end frequency based on holidays and summertime, otherwise not too bad in the early morning when the best animals are active.
Very quiet setting, recommended to get there EARLY, 8am when the park opens, to beat any crowds and big dive classes (they arrive around 11:30 or 12 usually). Gentle current allows good introduction into handling your buoyancy on a drift dive. Gentle sloping landscape underwater, worst thing you'll run into is tall grass or a sunken log.
In various spots the spring feeding the river bubbles up from the sand, and from small caves, which is quite interesting the first time someone experiences it (seeing the sand "boil," feeling the temperature differences). Large alligator gar and turtles may come by to say hello