Information about the status of Florida beaches is somewhat confusing. The conventional answer is - beaches are public. However, though it is true that the 825 miles of Florida beaches below the "mean high water line" are public, there is private ownership of dry sand beyond the "line," which in essence prevents public usage of the beach. In fact, according to the state’s Department of Environmental Protection, at least 60 percent of Florida beaches are private, offering little or no public access;
There have been several legal challenges to private ownership - and in some cases the court ruled in favor of the public, especially in areas that were traditionally used by the public. In practical terms, publically accessible beaches are open to the public, though sections of beaches adjacent to resort complexes and luxury condo buildings are often sectioned off, as within them beach services are rendered to the beach front property's residents and guests.
Here's a link to public access of beach and coastal areas