Outhaul

The outhaul is a fundamental sail control line used to shape the mainsail. As defined by Wikipedia, it is an element of the running rigging that attaches the mainsail clew to the boom and tensions the foot of the sail. It typically employs a block at the aft end of the boom and a cleat further forward to secure the line. By tightening the outhaul, the sail's foot is stretched, flattening the lower section of the mainsail and reducing its camber (draft). This is desirable in stronger winds to depower the sail and reduce heeling. Loosening the outhaul allows the foot to become fuller, increasing camber and generating more power in light airs. Proper adjustment is crucial for efficient sail trim. On many cruising yachts, the outhaul is a simple line led to a cleat on the boom, while racing setups may include purchase systems for finer control. For a deeper understanding of how lines like the outhaul interact with other deck hardware, see our guide on yacht rope handling and winches. Sail designer Frank Bethwaite recommended marking the boom with outhaul settings for different wind speeds, a practice still used by many racers. Explore more about sail handling and trim to master all your sail controls.