Long-tail boats are very common around Southern Thailand. This picture was taken at Koh Phi Phi Ley. They use a simple engine that is often seen in automobiles, but they make a put-put sound that is rather loud. Thais used them for everything from fishing to ferrying people around. They are called a long-tail boat because the propeller is mounted on the thrust shaft and juts out behind the boat a couple meters. It can be lifted from the water and rotated around making long-tail boats easy to maneuver.