To provide a ship for underwater sightseeing, which allows sightseeing passengers to dive under the water on an underwater embarkation machine, to practice underwater breathing, and moves by propulsion force of a propulsion machine arranged on the ship, for underwater sightseeing.

The ship 1 is used for underwater sightseeing. A lifting machine 3 is arranged on the ship. An underwater embarkation machine 4 is suspended by the lifting machine. The underwater embarkation machine is moved up/down between the water surface level and the underwater level in a moving range of the lifting machine. The ship is equipped with an air supply device. Sightseeing passengers wearing an underwater breathing apparatus that receives air to be supplied from the air supply device get into the ship on the water surface level, and dive under the water in the moving range of the lifting machine, and practice underwater breathing and enjoy the underwater sightseeing, by moving the ship by the propulsion force of the propulsion machine 2 arranged on the ship.