<p>Fig. 6. A keel on the bottom of the boat helps balance the force from the wind to balance the sideways momentum, prevent it from capsizing, and transfer the force of wind to motion forward.</p>

Fig. 6. A keel on the bottom of the boat helps balance the force from the wind to balance the sideways momentum, prevent it from capsizing, and transfer the force of wind to motion forward.

Image courtesy of Wikimedia Commons