Minecraft wiki entry for Ocean, associated text: Oceans are vast expanses of water, going from sea level all the way down to the ocean floor, which is at a depth of roughly Y=45. The seafloor is fairly hilly, featuring multiple peaks and valleys, and is mostly covered by a one-block layer of gravel, though some clay, dirt and sand patches may generate near the peaks. Ravines can occasionally generate on the ocean floor, forming underwater trenches. Some seafloor peaks may reach high enough to form islands on the surface of the ocean; these islands are typically small and may have very sparse vegetation with very little grass and oak trees. The seafloor is often covered with seagrass and kelp, with "forests" of kelp frequently reaching close to or even touching the water's surface. Fish, squid and dolphins frequently spawn within oceans. Shipwrecks and ocean ruins generate within all oceans, while deep ocean variants can occasionally generate ocean monuments.