PURPOSE: To provide a controller for automatically returning the attitude displacement of an outboard engine, generated according to the propulsion situation of a ship to the optimum state.

CONSTITUTION: Pressure sensors 16, 17 are provided in the upper and lower, opposite positions of the cavitation plate 15 of an outboard engine 1, and a controller 18 for detecting the attitude displacement of an outboard engine on the basis of differential pressure and/or differential voltage applied to these sensors 16, 17 is provided. The control signal of the controller 18 is transmitted to a PTT device (power-trim tilt device), and the PTT device drives a hydraulic motor for constituting the PTT device according to the control signal.