What component helps in guiding a boat to move forward or backward?

The propeller is a vital component in a boat's propulsion system, enabling it to move forward or backward. When the engine drives the propeller, its blades rotate through the water, generating thrust. This thrust propels the boat in the desired direction, with forward movement achieved by rotating the propeller in a standard direction and reverse movement generated by changing the direction of the rotation or using a separate reverse gear.

Understanding the role of the propeller is crucial for safe and effective boat operation, as it directly affects how the vessel responds to steering and throttle inputs. In contrast, the beam refers to the width of the boat, the gunwale is the upper edge of the boat's sides, and the stern is the back part of the boat; while these parts are essential for the overall structure and design of the vessel, they do not contribute to movement in the same way the propeller does.