In general, ship types are classified by the purpose, ownership, configuration, size, construction and/or propulsion. As these properties are not mutually exclusive, ship types cannot be inclusively classified in a hierarchy - rather, a ship type defines a number of vessels by the properties this class shares. These can be broad distinctions, such as 'sail powered', or quite narrow - such as a single-class race boat. This article considers a number of ship types:
Vessels may be categorized by distinguishing features. These features are innate to the vessel, without regard to how it is used or operated. The primary distinguishing features consist of:
Including the concept of generations (i.e., semisubmersible generations), these are temporal based distinctions:
Haphardly, various groupings of vessels:
See workboat(type) Workboats are service ships with industrial or support roles. They tend to be rugged deep ocean ships.
Merchant vessels are ships which exist for the purpose of generating revenue for the owner. They may follow a schedule (liner) or operate as per their need (tramp). Merchant ships can be classed by the type of cargo they carry (bulk, general).
Naval vessels are armed ships owned by nations.
Government owned ships do not (generally) generate revenue, rather continuously cost the country of ownership money. Lifecycle and aquisition costs in a political apmosphere drive designs.