I don't think this is so much the "government" as it is a council of local homeowners who don't want to share what they have with others. Talking about "urinating" and "rude behavior" makes the homeowners the victims, and therefor entitled to do as they please. People who have ocean- and river-front property always complain about swimmers, fishermen, and other folks in an effort to retain the exclusivity of their property, usually mentioning vandalism, littering, and other "rude behavior" to justify themselves.

Someone will go diving, be cited for violating the ordinance, and then it will work its way through the courts. If the law violates federal law, it will be rolled back, after the lawyers get paid.