Abstract: A trim tab apparatus capable of causing the stern of a vessel to be raised or lowered relative to the surface of the water in which it rests. A trim tab plane can be pivotally attached to one or more arms that can be attached to a vessel by one or more brackets. When the trim tab plane is rotated in an aft direction as a vessel is moving, the force of water passing under the trim tab plane causes the vessel stern to be raised. If the trim tab planes are rotated in a fore direction as the vessel is moving, water is forced across the top of the trim tab planes causing stern-drag, so that the vessel stern is lowered in the water.