IIRC from my law classes 50 years ago, Admiralty Law (federal Maritime Law) only applies to documented vessels. If the state set up a boat registration system, and the boat is registered in one of those states, state, not federal, law applies. And as has been pointed out in earlier posts, property liens vary considerably from state to state. The differences between documented boats and state-registered boats have both baffled and enriched lawyers for decades.I believe that the Marina's rights fall under Federal " Maritime" law and not state law. (Here in the U.S. at least) Not sure if it only applies to Navigable waters.
And none of this takes into consideration the confusion of liens (or any other legal matter) against vessels outside of the country they are registered/documented in. Being a Florida registered boat (not documented) in the Bahamas in the '80s gave both Bahamian and US local Customs all kinds of consternation when I cruised the boat in the Bahamas. Canada just didn't care when I trailered the boat and cruised there.
Stuart Mariner 19 #4133 Sweet P
Yeopim Creek, NC