On TVA lakes, you can fish around/under docks, just don't tie up to the dock or get on the dock. The dock itself is private but the water under and around the dock is public water. Some dock owners will try and run you off but as long as you are not tied up or on their dock they can't do anything. They might make noise and scare the fish, etc., and then others will chit chat with you and are nice people.