A hull is the main body of a ship or boat, designed to provide buoyancy and stability in water. It is the structure that keeps the vessel afloat and protects its interior from water. Hulls can be made from various materials, including wood, metal, and fiberglass, and their shape can vary depending on the type of vessel and its intended use. The design of a hull affects how a boat moves through water, influencing speed and maneuverability. Different types of hulls, such as displacement hulls and planing hulls, serve specific purposes. Displacement hulls are efficient for cruising, while planing hulls are designed for high-speed travel.