A navigation method for a ship which includes: a plurality of main generators that feed power to navigation equipment used in normal navigation and appliances for the living quarters provided within a ship body; and an emergency generator that feeds power to emergency equipment in case of fire or flood. The navigation method includes: an emergency power feeding step for feeding power to the emergency equipment using the emergency generator when at least one of the plurality of main generators is disabled due to fire or flood; and a return-to-port power feeding step for feeding power to return-to-port equipment, required for navigation for returning to port, using the main generators and the emergency generator after the fire or flood has subsided.