NOVELTY - An elastomer composition contains (b) nonhydrolizing hydrophobic liquid as a surface hydrophobilizing agent.    USE - The elastomer composition is useful as coated film on articles or structure which are used on the surface of water or under water; e.g.,water-proof sheet for buildings and tunnel, agricultural sheet, a protective sheet for buildings and vehicles, mesh sheet, mesh screen, polycarbonate roof, acrylic board wall, polycarbonate wall, guard rail, signals, road marks, guide plate, high-way wall, inner board of tunnel, road lamp, bridge, chimney, wall paper, mat, table cloth, fan, marking film, advertising plate, post, electric , tent, car, aircraft, ship and train, kitchen tools, e.g., dishes, fan, kitchen food and cooking table; furniture, wall household products, roll blind, artificial curtain artificial tatami, sofa, table, desk, door, cover for illuminating tools, ceiling, carpet, mat, bath tube, lid for bath tab, toilet seat, toilet, window, show case, mirror, lens, goggle and shield of helmet. The film of the composition is useful as cover film for solar battery, displays for electrical and electronic equipments, covers, mold-releasing film, film for agricultural house, electrets. The composition is also useful as sealant material, hydrophobilizing material and various kinds of additives. The composition is also useful as a lubricating agent, a fiber-treating agent, a conductive rubber, molding material and wax material. The composition is also useful as coated film on structure and articles in or under water, e.g., bent, concrete block, wave-breaking block, communication cable facilities, marine power generation instruments, a marine rig, fishing articles, power-generating articles, marine cable and transfer fishing articles. The composition is also used for living body-compatible articles, e.g., artificial blood vessel, organs, implanting tools, catheter, enlarging tools, binding equipment for surgery, in-vivo tube, connecting tube, separating film, flaw-covering material, test tube, laboratory dish, cultivating equipment and analyzer for biological substances.    ADVANTAGE - The coated film or film is highly hydrophobilized and prevents the surface from adhesion of stain including hydrophilic stain and has good weather resistance, chemical resistance, optical properties, e.g., transparency, mechanical properties, e.g., strength and elongation, good adhesion to base material, thermoresistance and heat yellowing resistance.    DETAILED DESCRIPTION - An elastomer composition comprises (a) elastomer and (b) nonhydrolizing hydrophobic liquid as a surface hydrophobilizing agent. INDEPENDENT CLAIMS are also included for a method of preventing articles or structure from adhesion of marine organisms