Federal law from late 1800's applies
I wish I could remember the exact details but there was an article in the Miami Herald about the Florida shoreline & public access. In the article the author found out there was a federal law from the late 1800's that declared all navigable waterways were the property of the citizens of the US and therefore access could not be denied by anyone to these waterways. The law, if what's left of my memory works, specifically included the ocean coasts.