The Ocean Railway is a massive transportation system designed by the Pig Army in Mother 3.5. It's a train of sorts built over a long bridge with tracks that travels between Nova Island and Supernova Island. The beams are held up and made of concrete, but aren't fixed into any point on the ocean floor as the ocean terrain around the islands strangely slopes downwards far too quickly. Instead, large floating rafts hold up the support beams from the bottom, and are fastened in such a way that they span the entire bridge from one island to the other. A single train goes back and forth across the bridge during the day, but the conductor sleeps during the night.