NOVELTY - The method involves constructing the seawall (6) having sufficient size to contain large sized heavy article, in the deck (3) using several empty marine containers (4,5). The upper opening of the sea wall is covered with a tidal protection tent. The large sized heavy article is carried out from the deck of the barge (1), after removing the tidal protection tent. The opening/closing section (7) is constructed to close the opening portion (X) of seawall using the empty containers, after bringing the large sized heavy article to the inside of seawall.    USE - Ocean transportation method for conveying large sized articles such as gas turbine/steam turbine, transformer, and generator, used in nuclear power station and thermal power station using ocean transportation barge (claimed).    ADVANTAGE - The large degree of freedom regarding the length, width and height of large sized heavy article can be enabled while conveying the large sized heavy article easily and preventing the contact of large sized heavy article with the sea water. Several empty containers can be used as a marine container at any time except during the construction of sea wall at the barge so that the container can be used efficiently. The inclination of the barge can be suppressed. The need for covering all the outer peripheral portions of side wall using the protection tent is eliminated so that the structure of protection tent can be simplified while enabling easier handling of tent, improving the operating efficiency of tent and reducing the cost for transporting the large sized heavy articles. The sea wall can be removed easily removed from the barge main portion while improving the operating efficiency of barge. The seawall having sufficient size to contain large sized heavy articles can be formed on the deck easily so that the deck-top can be used efficiently. The small sized heavy article can be conveyed easily using the light weight container, even if the size of barge is small.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for ocean transportation barge.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of ocean transportation barge.    Barge (1)    Deck (3)    Marine containers (4,5)    Sea wall (6)    Opening/closing section (7)    Opening portion of seawall (X)