A boat is a watercraft of a large range of sizes designed to float, plane, work or travel on water. Small boats are typically found on inland waterways or in protected coastal areas. However, boats such as the whaleboat were designed for operation as a ship in an offshore environment. In modern naval terms, a boat is a vessel small enough to be carried aboard another vessel. An older tradition is that a ship has a weather deck fully enclosing the hull space, while a boat lacks a full weather deck; this is suggested as the reason why submarines are referred to as 'boats' rather than 'ships', as a cylindrical hull has interior decks but no weatherdeck. Another definition is a vessel that can be lifted out of the water. Some definitions do not make a distinction in size, as bulk freighters 1,000 feet long on the Great Lakes are called oreboats. Ships are generally distinguished from boats based on their larger size, shape and cargo or passenger capacity.
Boats have a wide variety of shapes, sizes and construction methods due to their intended purpose, available materials or local traditions.