The outhaul controls and shapes the mainsail. Ease the outhaul to increase draft and power up the sail. Tighten the outhaul to flatten the sail and reduce drag and heel in heavy air.
Typical boat length:
Small Boat: 22' - 28' (6.7 - 8.5 m)
Midrange: 29' - 34' (8.8 - 10.4 m)
Big Boat: 35' - 42' (10.7 - 12.8 m)
Suitable for dinghies or small keelboats. A flexible cable shackles to the sail and enters the boom through a wire block. Placing a block aft of the cleat allows the crew to pull from a variety of positions.
A simple external outhaul system. A cascade of two 2:1 tackles produces a 4:1 advantage.
This 5:1 internal outhaul is popular on small offshore boats.
A 6:1 internal outhaul system is popular on small-to medium-sized offshore boats using a traveler car to carry the clew of the mainsail.
Mainsails that furl into the mast are loose-footed and usually have a ball bearing outhaul car that rides the length of the boom. The outhaul starts at the car, leads through the clew block on the sail, back to the sheave on the car, and into the boom where it leads to a winch.