In the post-war period more than 40 ships with chemical munitions containing more than 50 thousand tons of active mass of toxic substances were sunk in the Baltic Sea water area. By the present time due to intensive corrosion there is a possibility of ships depressurization and entry of mutagenic and carcinogenic pollutants into the Baltic Sea water area, which causes the necessity of their isolation. To solve this problem the method of underwater objects burial is developed, which consists in primary cleaning of the vessel from bottom sediments, their replacement by concrete mixture, hydrotransported from the board of the technological vessel with the use of polyfunctional equipment. It is proposed to use local coarse-grained material, extracted and prepared directly in the water area of works, as a mixture filler. The technical means developed for the works are reliable and simple in operation, highly productive, allow to prevent an ecological catastrophe in the Baltic Sea water area in the shortest possible time and with high efficiency.