A tilt and trim system for the outboard drive of a marine propulsion unit wherein the popping up action is effectively damped without positive stops that could cause abrupt stopping and possible damage. The second list is merged with the one or more tags in order to generate the first list which is sent to the first data processing node. Since the error signal is a difference between two laser beams coming from an identical laser source, the variation of laser power could be eliminated. Subsequently, a default frame rate is changed to a value that has been preset for the program type. The optical system is then calibrated so that this relationship corresponds to in-phase beams when the optical system is aimed at boresight.