Minecraft wiki entry for Building_a_metropolis, associated text: Boats: If your metropolis is spread across several islands, then build a boat network. Have harbors at every island and make buoys in the water with signs directing people to other harbors. You can also have canals, but these might get in the way of your construction. Boats can also be used on land, moving especially fast on certain blocks. This is a great way to transport mobs!