Abstract: Adjustment is made of the position of a marine transportation system including a boat having a drive, a trimmable port tab and a trimmable starboard tab. The operation of the marine transportation system is monitored to provide an output distinguishing boat operation in an on-plane condition and boat operation in an off-plane condition, to provide an output distinguishing boat travel in a straight forward condition and boat travel in a turning condition and to provide an output distinguishing boat operation in a first heel condition in which the boat tilts to port and boat operation in a second heel condition in which the boat tilts to starboard. The port and starboard tabs are positioned at desired positions in response to the outputs. According to the embodiment, a heel adjustment operation of the boat is carried out during boat operation in an on-plane straight forward travel condition, only.

Abstract: A marine automatic steering apparatus in which a part or whole of its control circuit is doubled as dual steering control sections same in construction includes a non-volatile memory controlled by either of the dual steering control sections and in and from which data can be written and read out.