Changing course to increase the TWA. After changing tack a skipper will often bear away a few degrees below a close-hauled point of sail in order to accelerate to maximum hull speed before gradually heading up to a close-hauled point of sail.
Head up
Changing course to decrease the TWA. When running before the wind and after a gybe a skipper will often head up a few degrees above the optimum TWA for fastest VMG in order to accelerate to maximum hull speed before gradually heading down to that optimal TWA for a run.