A SCOW is a flat-bottomed boat with a blunt bow and a square stern, often used for carrying cargo. It is typically propelled by oars, sails, or a motor. A TUG is a powerful boat designed to pull or push other vessels, usually through the use of a tow line. Harbor boats are vessels that are used in harbors and ports to transport goods, passengers, and other materials. The two most common types of harbor boats are scows and tugs.