Ocean or river, the rules are the same. We own over a mile of the Jefferson River, here in SW Montana. Our deed is a homestead dating back to 1864. We pay the taxes for the hard ground UNDER the river, but of course not the water. There are are times that "drifters" coming down the river think the beaches along our part are public property. Some are so insistent, that I now carry a gun most of the time up here. My wife & I came across a couple that just wanted a rest & to eat lunch. We let them stay. I think one needs to play the hand dealt at the time. You cannot stop people from use public water. I don't think we should.
Last century there was a landowner in CO trying to prevent paddle boats off his river/land. He owned the land under the water and did not like the constant trespassing on his land. Not sure whatever happened to his case but it does seems like after many years it was decided. I just can't remember the decision.
We own land and while we do not have frequent trespass issues we do have problems every year or so. Some $%^&*( piece of %^&*( just dumped some trash near our gate. The %^&* lazy, good for nothing %^&*( threw the trash into down slope into the woods. He did this on a Friday and I did not see the trash until Monday morning when it started to ran for a few days. By the time I could clear a trail to the trash, it had been at least 5 days so the garbage was rather ripe. If the ^&*( son of a ^%&*( had just left the garbage at the gate it would have been easier since I was going to the dump on Monday morning when I saw his waste. If the trash had not been so ripe I as going to go through the trash and return it to sender.
The $%^&*() guy that did this was most likely working on a neighbors house. However, in the past we have had "neighbors" dump yard waste and used cat scat on our land. One twit dumped trash on the land behind us which took more effort than taking the trash to the dump where he could have dumped for FREE. The dump is right behind the only two grocery stores for 20 miles so the ^%&*()_ lazy ^&*() could easily have taken the trash to the dump when getting groceries instead of spending all of the time he did to dump in the woods.
There are ^&*()&*()^%$$% on land and they don't change when they get a boat.
The abandoned boat problem can easily be solved if the state wants too. There are laws in place to deal with abandoned cars and the same legal process could be used with derelict boats. Given how much FLA makes off of boat registration and the boat use tax, the state can afford to remove derelict boats.
The derelict boat issue is just a red herring to prohibit boats from anchoring.
Later,
Dan