An air ejecting unit is configured to eject air into water from an air ejecting outlet provided in a ship bottom of a ship body. An air recovery device is configured to recover the air into the ship body from first to third air recovery inlets provided in the ship bottom. The first air recovery inlet is provided to cross the center line. The second air recovery inlet is provided to project on a port side from the first air recovery inlet. The third air recovery inlet is provided to project on a starboard side from the first air recovery inlet. The second and third air recovery inlets are arranged on a bow side from the first air recovery inlet. Each of the first to third air recovery inlets includes a plurality of air recovery holes.