What is the function of a rudder on a boat?

The rudder on a boat serves the vital purpose of steering. It is a hinged or pivoted device located at the stern (rear) of the vessel and is used to change the direction of the boat by redirecting the flow of water passing over its surface. When the helmsman turns the steering wheel or tiller, the rudder moves, creating a force that alters the boat's course. This steering capability is essential for navigating waterways, avoiding obstacles, and ensuring safe, controlled maneuverability.

While other options relate to important functions of a boat, such as generating speed (which is primarily the role of the engine and hull design), stabilizing the boat (often achieved through hull shape and ballast), or anchoring (which involves dropping an anchor overboard to hold the boat in place), they do not pertain to the primary role of the rudder itself. The rudder's sole focus is on steering, making it an indispensable component of a boat's navigational system.