Leech Meaning in Sailing

The leech represents the back (trailing) edge of a sail, stretching from the top corner (head) to the rear corner (clew). The shape and tension of the leech are critical for the sail’s aerodynamic performance and for controlling how much ‘twist’ the sail has. Sailors adjust the leech using a ‘leech line’ or by changing the tension of the ‘main-sheet’ and ‘boom vang.’ One specific example involves a sailor noticing the leech of the sail is vibrating or ‘fluttering’ and pulling the leech line tight to stop the noise and wear. A ‘tight’ leech provides more power in light winds, while an ‘open’ leech allows the boat to spill excess air in heavy gusts. Proper management of the leech is essential for balancing the boat’s speed and its tendency to lean. It is the final exit point for the wind as it passes over the sail.