Minecraft wiki entry for Water-powered_boat_transportation, associated text: Water-powered boat transportation is a flexible and reasonably easy way to transport mobs and villagers along arbitrary paths (even uphill‌[Bedrock Edition only]) using only the power of flowing water, without the need for any tools more exotic than a bucket and pickaxe, and needing only three common materials (water, buttons or signs, and common building blocks). No rowing, rails, minecarts, redstone gadgets, or bubble columns are needed, just a boat and water. With proper water management, one can construct flowing moats around arbitrary areas in which a boat can circle endlessly. The boat can even change elevation up or down using only the power of water flow.