These words denote types of hollow structures, capable of floating and of carrying considerable weight, that are used to move goods and people over water. Vessel , in accordance with its original meaning of a hollow receptacle, suggests a large structure, usually in terms of its function of carrying goods or people or of being engaged in a specific type of commercial enterprise: a merchant vessel ; a passenger vessel ; a whaling vessel .

Ship is generally applied to large seagoing vessels when the type of propulsion is being stressed: a steamship ; a motorship ; a sailing ship . Ship also carries the implication of a vessel that has distinctive and even personal qualities for the men who sail in it, and is traditionally referred to by the feminine form of the personal pronoun.

• The captain and the crew all went down with the ship ; The Bounty was a notorious ship ; She was a gallant ship .

In literature and in figurative uses, ship suggest poetic and emotional overtones that are not inherent in any of the other words here considered.

• "I have seen old ships sail like swans asleep"; "Sail on, O Ship of State!"; Pray for our Ship , the Church.

Boat and craft may both be used as general designations for all these structure. Craft is more generalized than boat in that it does not have any specific connotations as to size, use or means of navigation. Although it is somewhat indefinite in meaning, craft may be used in the singular. Our craft was moving at nine knots. More commonly craft is a collective noun: hundreds of sailing craft ; a harbour full of small craft ; a fleet of fishing craft . Boat is applied loosely to watercraft of any size: to cross the river by ferryboat ; to go to Europe by boat ; to race a sailing boat . In a narrow sense, boat is applied to any small, open craft propelled by oars, sails or an engine: a rowing boat ; a speedboat ; a lifeboat . According to an old naval rule, if a vessel can be hauled out of the water it’s a boat ; otherwise it’s a ship .