Tack (sailing)

A tack is a nautical term both for the lower, windward corner of a sail and, separately, for the windward side of a sailing craft (side from which the wind is coming while under way—the starboard or port tack. Generally, a boat is on a starboard tack if the wind is coming over the starboard (right) side of boat with sails on port (left) side. Similarly, a boat is on a port tack if the wind is coming over the port (left) side of boat. However, confusion can result when a boat is on a 'run', with the wind coming directly from astern and the mainsail and jib/genoa are on opposite sides of the vessel (wing-on-wing). Therefore, the windward side is defined as the side opposite to that on which the mainsail is being carried. On a starboard tack the mainsail is carried on the port side. On a port tack the mainsail is carried on the starboard side. It is the position of the mainsail that determines the tack.