Confidence votes 173K. There are three kinds of answers: ones that are mostly right, ones that are mostly wrong, and those that once were right but now are wrong. A steamboat uses an external combustion engine. A burning wood or coal fire heats the water in a boiler until the steam pressure is very high.This pressure is released into the drive mechanism to turn the engine shaft, normally connected to one or more paddlewheels that move the boat through the water.onfidence votes 173K. There are three kinds of answers: ones that are mostly right, ones that are mostly wrong, and those that once were right but now are wrong. A steamboat uses an external combustion engine. A burning wood or coal fire heats the water in a boiler until the steam pressure is very high.