When you stop for fuel, keep in mind that other boats may be waiting to get to the fuel dock. Do not leave your boat to pick up groceries or hang out in the bait shop. Tie up securely, follow proper fueling procedures, pay the bill and move away to another docking area or guest slip if you need to do other business ashore.
If you are already safely docked in the marina and there is no dockmaster or helper around to assist boaters as they dock and undock, it is courteous to assist others in your vicinity with their lines. This may sound like an oxymoron, but boating is like a fraternity of individuals. Everyone has a right to their space but everyone provides assistance whenever necessary.
Make sure to keep the area around your slip clear. Roll up and stow hoses, place power cords in such a manner as to not trip a passerby who is looking up at your new radar reflector. Keep buckets, mops, tackle, docking lines and other items stowed in their proper place, not strewn around on the dock. When finished with carts or other equipment at the marina intended for common use, be sure to put it back where it belongs so others have access.