PURPOSE: To make it possible to sail a ship at the maximum speed and as well to aim at enhancing the efficiency and accuracy of sailing, by correcting the course of sailing in accordance with data of the azimuth, wind direction, wind speed and course, and as well by always correcting the angles of sail and rudder in accordance with the outputs of a ship speed computing device and a compensating device.

CONSTITUTION: Sailing data obtained by a computing device 8 in an autopilot is transmitted to a ground radio station from a transmitter 17, and a course change information is received from the ground radio station into the device 8. Meanwhile, a ship speed computing device 4 computes the difference between a desired value and the maximum ship speed which has been beforehand computed in accordance with the present wind direction and wind speed and azimuth, and delivers it to the device 8. Further a compensating device 7 receives feed-back data from sailing and rudder angle detectors 12, 15 and data from azimuth and wind sensors 5, 6 to perform compensating computation the result of which is delivered to the device 8. The computing device 8 receives a course indication signal and a course change information signal, and selects an indication value determined by the difference of the change value. Further, the computing device 8 selects an optimum sailing azimuth in accordance with possible sailng speed information, wind direction and speed information, and correction data. Further, the output of the computing device 8 is delivered to sail and rudder drive devices 10, 13 so that the angles of sail and rudder are subjected to feed-back control, thereby the maximum speed sailing is made possible.