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.

Sail corner

The tack is the corner on a fore-and-aft sail where the luff (the forward edge) and foot (the bottom edge) connect^[1] and, on a mainsail, is located near where the boom and mast connect.^[1] On a square sail or a spinnaker, the tack is the windward clew (lower corner) and also the line holding down that corner; when the vessel changes course to have the other vertical edge of the sail to the wind, the other clew becomes the tack.^[2]

Wind direction on sailing vessel

As a point of reference, tack is the alignment of the wind with respect to a sailing craft under way. If the wind is from

When a boat is running with the wind coming directly from astern and the mainsail and jib are on opposite sides of the vessel, the windward side opposite to that on which the mainsail is being carried. On a starboard tack the mainsail is on the port side; on a port tack the mainsail on the starboard side.[4]

References