A trimaran is a type of three-hulled craft, which is a boat or ship with three separate hulls. It is typically used for recreational sailing and racing, as well as for commercial purposes such as fishing and transportation. The main hull is usually larger than the two side hulls, and the side hulls are connected to the main hull by outriggers. Trimarans are known for their stability and speed, and they are often used in long-distance sailing.