Tack (sailing)

Tack is also a nautical term both for the lower, windward corner of a sail.

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

[1] The maneuver of changing a sailing craft's course from one tack to the other during which the wind direction is brought across the bow is called tacking; with the wind direction brought across the stern, it is called jibing for fore-and-aft rigged sailing craft, or wearing ship for square-rigged vessels.

[2] 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 is considered to be that opposite to the site on which the mainsail is being carried.

[4] 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.