Create massive industrial sci-fi spaceships with a brutalist aesthetic. The ships should resemble deep-sea submarines — long, heavy, and functional, with riveted steel plating, external pipes, sonar domes, fins, and periscopic sensors. Emphasize blocky, angular structures, exposed machinery, and a utilitarian design — no sleek or elegant curves. Use dark matte metal textures, harsh shadows, and minimal lighting, except for a few glowing orange or red signal lights. The overall look is oppressive, raw, and built for war, floating in deep space like underwater leviathans.