A steering system includes: a steering wheel; a steering wheel sensor configured to detect an operation angle of the steering wheel; an actuator configured to turn an outboard engine; a plurality of turn angle sensors including a first turn angle sensor configured to detect a turn angle; and a control unit configured to calculate a controlling turn angle, and to drive the actuator to turn the outboard engine in accordance with a difference between the controlling turn angle and the turn angle. If an anomaly of the first turn angle sensor is detected, the control unit continues to drive the actuator based on information from a second turn angle sensor in a normal state, and drives the actuator so as to limit the turn angle of the outboard engine as compared with a case in which the first turn angle sensor is in a normal state.