A semisubmersible water surface navigation ship with even draft comprising at least two lower hulls, which can be submerged under water to reduce resistance and have a shape affording low friction resistance, and which are equipped with lifting and diving planes, at the bow and stern parts, and an upper hull above the water surface being connected to the lower hulls by way of water breakers. In order to keep an even draft or trim during navigation, the lifting/diving force capacity of the lifting and diving planes is designed to be greater than the buoyancy change of the water breakers owing to loads such as waves and wind. Steering rudders, propellers and water ballast tanks are installed in order to cause the ship to navigate or lie to under any one of a shallow draft state, a semisubmerged state and a deep submerged state. The upper hull is provided with superstructures with sufficient reserve buoyancy for maintaining the stability of the ship under the deep submerged state. Barges carrying cargoes can be mounted on or dismounted from the upper hull in the deep submerged state, and thus they can be loaded and unloaded in an integrated manner.