A navigator draws a route on a chart to navigate a ship from an origin port to a destination port. Then, the navigator sails the ship based on the route. In other word, the navigator misidentifies the route there is a possibility of running aground. In order to prevent navigator's misidentifies, this study proposed a sea route display system which displays the sea route on the surface of the sea by using augmented reality so that navigator may grasp the ship's position from the sea route easily. Effectiveness of the developed system was carried out with actual ship experiment.