JPH0557960B

A marine autopilot apparatus having a microcomputer for controlling a rudder control loop formed of at least a rudder servo amplifier, and a power unit, for detecting an abnormality concerning the steering of a rudder and for indicating an alarm concerning the detected abnormality and the like. A representing alarm indicator lamp classifying the abnormalities into a single or plurality of groups and for collectively indicating the abnormalities in the form of the single or plurality of groups. A general-purpose indicator for indicating various data at least concerning the steering, set values and respective contents of the abnormalities detected and a rudder control collective alarm circuit for indicating the occurrence of the abnormality in the rudder control loop. The rudder control collective alarm circuit is driven when at least one of a plurality of alarm points within the rudder control loop, and the power unit exhibits an abnormal condition.