What does leech tension affect?

• A. It increases lift
• B. Let you point the boat close to the wind but are not as powerful
• C. It decreases hull speed
• D. It increases power upwind

Answer: (B)

Leech tension controls how twisted the sail is along its trailing edge. When you tighten the leech, the sail becomes flatter and twist is reduced. A flatter sail up close to the wind helps the flow stay attached and lets you point higher toward the wind. However, with less twist and a flatter sail, the driving power you get from the sail decreases. So you gain the ability to sail closer to the wind, but you don’t have as much power available. That’s why the effect described is that tightening the leech lets you point closer to the wind while reducing overall power.