Sail

An assemblage of fabric used to catch the wind and propel a vessel. Sails can also be solid, though that is less common.

Triangular sails are commonly used on kayaks. The three vertices are known as:

head tack clew luff foot leach

the top forward bottom aft bottom the leading edge of the sail the bottom edge of the sail the trailing edge of the sail (also spelled leech)

The sail is raised and held up with a halyard. The clew is held into place with a sheet. The tack, if not fixed to the deck, is controlled with a guy.

Luff as a verb

To luff is to point up into the wind too high for the set of the sail. This causes the sail to become backwinded and the luff begins to flap. Luffing can be stopped by tightening the sheet and bringing the sail in closer to the boat. If sailing as close to the wind as possible, luffing indicates you are attempting to point too high - the only solution then is to turn off the wind or either tack or gybe to take a different course.

Tack as a verb

To tack is to turn into the wind, change direction and set the sail on the opposite side of the vessel. Tack is also used to refer to changing direction to sail towards the wind. Changing direction by turning away from the wind is to gybe.

See Fixed rig sailing. Kayaks sometimes use other types of sail - see Kite sailing and Umbrella sailing.