Ship

A ship is a large watercraft designed for travel across the surface of a body of water, carrying cargo or passengers, or in support of specialized tasks such as warfare, oceanography and fishing. Ships are generally distinguished from boats, based on size, shape, load capacity and purpose. Ships have supported exploration, trade, warfare, migration, colonization, and science. Ship transport is responsible for the largest portion of world commerce.

The word ship has meant, depending on era and context, either simply a large vessel or specifically a full-rigged ship with three or more masts, each of which is square rigged.

The earliest historical evidence of boats is found in Egypt during the 4th millennium BC. In 2024, ships had a global cargo capacity of 2.4 billion tons, with the three largest classes being ships carrying dry bulk (43%), oil tankers (28%) and container ships (14%).

Ships are typically larger than boats, but there is no universally accepted distinction between the two. Ships generally can remain at sea for longer periods of time than boats. A legal definition of ship from Indian case law is a vessel that carries goods by sea. A common notion is that a ship can carry a boat, but not vice versa. A ship is likely to have a full-time crew assigned. A US Navy rule of thumb is that ships heel towards the outside of a sharp turn, whereas boats heel towards the inside because of the relative location of the center of mass versus the center of buoyancy. American and British 19th century maritime law distinguished "vessels" from other watercraft; ships and boats fall in one legal category, whereas open boats and rafts are not considered vessels.

Starting around the middle of the 18th century, sailing vessels started to be categorised by their type of rig. (Previously they were described by their hull type – for example pink, cat.) Alongside the other rig types such as schooner and brig, the term "ship" referred to the rig type. In this sense, a ship is a vessel with three or more masts, all of which are square-rigged. For clarity, this may be referred to as a full-rigged ship or a vessel may be described as "ship-rigged". Alongside this rig-specific usage, "ship" continued to have the more general meaning of a large sea-going vessel. Often the meaning can only be determined by the context.

Some large vessels are traditionally called boats, notably submarines. Others include Great Lakes freighters, riverboats, and ferryboats, which may be designed for operation on inland or protected coastal waters.

In most maritime traditions ships have individual names, and modern ships may belong to a ship class often named after its first ship.

In many documents the ship name is introduced with a ship prefix being an abbreviation of the ship class, for example "MS" (motor ship) or "SV" (sailing vessel), making it easier to distinguish a ship name from other individual names in a text.