A paddle steamer is a steamship or riverboat powered by a steam engine that drives paddle wheels to propel the craft through the water. In antiquity, paddle wheelers followed the development of poles, oars and sails, where the first uses were wheelers driven by animals or humans. Modern paddle wheelers may be powered by diesel engines. Save for tourism and small pleasure boats (paddle boats), paddle propulsion is largely superseded by the screw propeller and other marine propulsion systems that have a higher efficiency, especially in rough or open water.