Minecraft wiki entry for Acquiring_a_conduit, associated text: If you are fortunate enough to find a shipwreck in reasonably shallow water (enough for you to dive down, linger for about 5 seconds, and return to the surface), go straight for the map chest. This is located in the lower section of the stern of the ship. You likely have to open a door to get into that section. Open the chest, get the map (not the blank pieces of paper, but the paper with a mark on it), and don't be distracted by anything else. Return to the surface immediately after obtaining the map. If you want to explore the ship, save it for another breath.