Trim is the running angel of the yacht as it makes way in the water. Trimming a yacht means to either raise or lower the bow, hence adjusting the angle of the yacht with water level. The most efficient pitch attitude, changes with speed so trim tabs are adjusted based on speed and weight displacement to maintain an efficient pitch attitude.
A pair of movable ‘flaps’ mounted on the transom of a yacht. When interacting with the water they deflect the flow of water along the yacht. When lowered, the tabs create lift at the stern, lowering the bow. Along they create drag, reducing the efficiency of the hull shape.
The capability of outboards and stern drives to adjust the angle of thrust by tilting it ‘out’ or ‘in’.