Gator Park is situated on the eastern edge of the Everglades on SR 41 which runs between Miami and Naples. There are several similar places nearby and many others offering airboat rides all along this road. We chose this one because it was advertised and we had coupons reducing our admission to $18.
The highlight was the airboat ride. This was on a largish airboat with about five rows of seats all at the same level so it would be best to be in the front row for the best experience. As explained by others, the beginning and end is through a narrow channel at slow speed looking out for wildlife, mainly alligators of the 6-8 feet variety. Once in the open the thrill part of the ride starts, speeding across the water and grass.
Back at the start point there is then a short show which in our case consisted of a presenter displaying up close a baby alligator and then a slightly larger one with its mouth taped up. It is possible to hold the larger one and have your photo taken with it ($2 if you use your own camera, $5 if their's). The presenter then gets in with a very docile larger alligator to demonstrate a few things like its jaw reflex action.
There are more alligators in pens and some snakes to look at. A souvenir shop and eating area are also to be found although it does not look like much of the profits have been spent on it lately.
The staff actively solicit tips so have some dollar bills handy.
I found this a fairly average experience. As there is plenty of wildlife to see in the National Park then it's the airboat ride that is of the main interest. I would recommend that you do your homework first to find out what others think. The smaller the airboat the more exciting it is but generally more costly.