Minecraft wiki entry for Trading, associated text: A few advantages about fishermen still exist: First, they have the cheapest coal trade compared to other coal-trading professions (10:1 instead of 15:1), so it can be useful if the player has a lot of coal from mining or killing wither skeletons. Second, all four types of fish they buy can be farmed in large quantities, with tropical fish and pufferfish having the better deals among the four. Third, they buy one boat for one emerald, a reasonably good deal.