Rule 12 of the Navigation Rules defines which sailing vessel has the right of way when two sailboats that are in sight of each other approach and risk of collision exists. Remember that “in sight” means visually; if you see a vessel on radar or AIS and not with your eyes, it is not in sight.
(1) When each sailboat has the wind on a different side, the vessel with the wind on the port side shall keep out of the way of the vessel with the wind on the starboard side. Starboard tack has right of way.
(2) When both sailboats have the wind on the same side, the vessel that is to windward shall keep out of the way of the vessel that is to leeward.
(3) If a sailboat on port tack (wind on the port side) can’t determine which tack the other vessel is on, the port tack vessel shall keep out of the way of the other vessel.
(4) When a sailboat overtakes another sailboat or a power-driven vessel, the overtaking boat always keeps out of the way, and it should keep going until well past and clear of the other vessel. Don’t cut in ahead of the vessel or cross in front of her. Rule 13 discusses overtaking. The text for Rules 12 and 13 is available at http://www.navcen.uscg.gov/?pageName=navRulesContent