Minecraft wiki entry for Achievement_guide, associated text: As long you live in the ocean, this achievement is easy to achieve. If you don't live in the ocean, you need to find one. Create a map using a cartography table, so it only costs one paper instead of nine. Then, add a pointer by adding a compass to an empty map. After an empty locator is created, use the map and zoom in from scale level 1:1 to 1:8, which requires 3 papers if zoomed in using a cartography table. As you fill the map, you having a high chance to find ocean ruins, since it's commonly generated in the ocean, but rarely on lands. This method is very effective for frozen ocean biomes and deep variants since dolphins don't spawn here. Keep your eyes peeled, ocean ruins are made of a block, which resembles the ocean floor, in regular ocean, cold ocean, frozen ocean, and their deep variants ruins primarily made out of stone brick as the ocean floor is gravel, while in warm, lukewarm, and their deep variants primarily made out of sandstone as the ocean floor is sand.