The long-tail boat, known as Ruea Hang Yao (เรือหางยาว) in the Thai language, is a type of watercraft native to Southeast Asia, which uses a common automotive engine as a readily available and maintainable powerplant. A craft designed to carry passengers on a river may include a lightweight long canoe hull, up to 30 metres, and a canopy. There is much variation among these boats, some have evolved from traditional craft types, while others have a more improvised look—the sole defining characteristic is a secondhand car or truck engine.