Patent ID: 8376791

Claim:
A method of controlling a surface drive for a watercraft ( 100 ) with at least one drive unit ( 140 ) comprising a thrust tube ( 105 ) which directs a propeller shaft ( 106 ) and trimming and steering actuator mechanisms ( 180 , 181 ) that are controlled by an electronic control unit ( 130 ), the thrust tube ( 105 ) being vertically pivotable within a trimming range (τ_G) around a trim angle (τ) around a hinge point ( 111 ) attached to a transom ( 104 ) and horizontally pivotable within a maximum steering angle (σ_L) around a steering angle (σ), the propeller shaft ( 106 ) being hingedly connected to a drive train ( 125 ) at the hinge point ( 111 ), and the surface drive being operable in at least one automatic operating mode and at least two different operating ranges (S 3 , S 4 ), the method comprising the steps of: automatically changing the operation mode when the operating range changes; automatically controlling the adjustment of the trim angle (τ) in at least one controlled operating range (S 3 ) in a controlled automatic operating mode, with the detection of values of preset control parameters, where the automatic control adjusts the trim angle (τ) to achieve a preset desired trim angle (τ); and automatically regulating the adjustment of the trim angle (τ) in a closed control loop in at least one regulated operating range (S 4 ) in a regulated automatic operating mode, with detection of values of preset control parameters, where the automatic regulation adjusts the trim angle (τ) to achieve either a defined maximum rotational speed (n_ 40 ) or a maximum headway speed of the watercraft (v_ 40 ).