Leech (Sail)

The trailing edge of a sail between its head and clew.

On most fore-and-aft sails the leech is the aft edge, but ‘trailing edge’ is the more general definition and also applies to sails whose orientation is less conventional. Its shape may be supported by battens and controlled by sheet tension, twist, mast bend, vang or a leech line.

A leech that is too loose can flutter and fatigue the cloth, while excessive tension can hook it to windward and distort airflow. Tears, batten-pocket damage and leech-line chafe require attention because loads concentrate along this edge.