When we talk about going fast upwind, one of the biggest players in your speed game is draft—the depth and position of the belly of your sail. It controls how much power you generate, how well you point, and how controllable the boat feels as the wind builds. And one control more than any other helps you tune this on the fly: the downhaul also known as the cunningham. What is the draft? Draft is the maximum curve in the sail. A deeper draft gives you more power—great for acce

When we talk about sail shape, most sailors think about draft depth or position. But one of the most influential features is the leech ....