What kind of forces does a semi-balanced rudder typically counteract?

A semi-balanced rudder is designed to effectively counteract thrust and drag forces that act on a vessel during movement. By utilizing its particular design, which includes a portion of the rudder placed forward of the pivot point, it can create a moment that helps to offset the hydrodynamic forces generated by the vessel's movement through the water. This design allows for improved maneuverability and a stronger steering response when dealing with the forces that are generated by thrust—pushing the vessel forward—and drag—resisting this forward motion. Thus, the application of a semi-balanced rudder is particularly effective in managing these two interacting forces to help maintain the desired course and stability of the vessel.