Righting moment

When the wind pushes on the sails, the boat heels. Its weight and shape create a force that brings it back upright: the righting moment. The larger it is, the more the boat can turn wind force into speed instead of lying over.

Designers increase it with beam, low ballast (deep keel, canting keel) or water ballast. Rules sometimes limit it, because it is what makes a boat powerful.