If you keep the boat
in the water
you will probably have to register the boat
in the state where the boat is moored, even if you live in a different state. So if you live in VA but the boat is in MD you would register the boat in MD.
To place a permanent mooring
you will have to check local regulations
but most likely some agency somewhere will have some say in the matter. Hopefully someone from the area can help with that.