To provide a foldable ship which is easy in transportation and high in safety.

At transportation, a main ship body is folded and accommodated in one or more boxes or traveling bags, and the main ship body can be transported by using a vehicle, a tram car or an airplane. When used as a ship, the main ship body is swollen, one or more boxes or traveling bags are set at the inside of the main ship body and made to serve as an auxiliary and supplementary floating body (floating storage) of the main ship body. Furthermore, the main ship body is well utilized as a case, a floating body and a floating storage such as a trunk.