If your left hand is closest to the mast, then you are sailing port. Overtaking vessels must yield If you are sailing behind someone it is your responsibility to steer sail around them at a safe distance, as they are unable to see you. When on the same reach the downwind sailor has the right of way. Don't Jibe into another sailor 5.
Commercial vessels have the right of way over everyone.
It is the Windsurfer's responsibility to keep clear of commercial vessels including barges. Most vessels cause suction from their propellers and create stern wakes. Many may have have a cable extending several hundred feet to a partially submerged log raft. These vessels can block the wind, leaving you unable to maneuver. Believe it or not Barges can easily sneak up on you.