What is the purpose of a 'keel' on a boat?

The purpose of a 'keel' on a boat is to increase stability in the water. The keel is a structural element that runs along the bottom of the hull, extending vertically downward in many cases. It is designed to counteract the forces of wind and water when the boat is in motion, providing a means of stability and balance. By keeping the boat upright and ensuring it doesn’t easily tip over, the keel allows for safer navigation, especially in challenging weather conditions.

In contrast to the other options, which do not accurately reflect the function of a keel, it's important to understand that while steering mechanisms, safety features, and width measurements play roles in boat operation, they pertain to different components of vessel design rather than the keel's primary purpose of enhancing stability.