In a ship steering system for an out-drive device including: an out-drive device; a hydraulic actuator configured to turn the out-drive device; a hydraulic controller configured to control the hydraulic actuator; a ship steering device configured to instruct a traveling direction to the hydraulic controller; and an emergency ship steering device capable of at least instructing the out-drive device to turn, the emergency ship steering device is capable of controlling the hydraulic actuator without involving the hydraulic controller.