Steering a boat is different from steering a car; moreover, it differs in three distinct and important ways. In a car, the front changes direction and the back follows the front around the curve. In a boat, the rudder kicks the back to one side or the other and the craft basically skids around the curve. The pivot point for a car is at the center of the front bumper. The pivot point for a boat might be well forward of the front, if it is a powerful planing hull, or well aft of the front for a sailboat.
Steerage wayLike the steering in a car, a boat rudder has no effect if the boat is standing still. Unlike a car, however, the rudder has little effect at low speed and becomes increasingly effective as the boat moves faster. This speed, which allows the rudder to steer the boat, is called steerage way.
Prop walkWhen in reverse, as the propeller moves the boat backward by pushing water forward, it also moves the stern somewhat sideways. This motion, called prop walk, tends to kick the stern to the left if the prop is right handed, and therefore rotates clockwise as seen from astern, or to the right in the much less common case of a left handed prop. It is most evident at high engine RPM when the boat has no steerage way on and is standing still or barely moving. Prop walk can be useful for turning the boat. This works only in reverse, however, and only when pivoting in the direction of the prop walk. On an unfamiliar boat, test for prop walk by revving the engine briefly in reverse, perhaps while still tied up at dock, and watching to see which way the stern moves. When prop walk is not wanted, reduce it by keeping engine RPM low, in reverse, until you have steerage way on.