Merchant ship

A merchant ship, also called a merchant vessel, trading vessel, or merchantman, is a boat or ship used to move goods or carry paying passengers. This sets it apart from pleasure craft, which people use for fun, and naval ships, which serve military purposes. These vessels come in many sizes and shapes, ranging from six-meter inflatable dive boats in Hawaii, to Mississippi River casino boats holding over 5,000 passengers, to tugboats in New York Harbor, to 300-meter oil tankers and container ships at major ports, and even passenger-carrying submarines in the Caribbean.

Many merchant ships sail under a "flag of convenience" from a nation different from the owner's home country, such as Liberia or Panama, because those countries have more favorable maritime laws. The Greek merchant marine is the largest in the world; today, the Greek fleet makes up about 16 percent of global tonnage, making it the biggest single international merchant fleet currently, though not the largest in history. During wars, merchant ships may serve as auxiliaries to their countries' navies and are called on to transport military personnel and supplies.

**History**

**Definitions** The United States Coast Guard defines a "commercial vessel" as any boat or ship involved in commercial trade or carrying passengers for hire. In English, "Merchant Navy" without further detail refers specifically to the British Merchant Navy, while the United States merchant fleet is called the United States Merchant Marine.

**Name Prefixes** Merchant ship names often include a prefix indicating the vessel type: - CS = Cable Ship or Cable layer - LNG = Gas carrier for liquefied natural gas - LPG = Gas carrier for liquefied petroleum gas - MFV = Motor Fishing Vessel - MS = Motorship - MSV = Motor Stand-by Vessel - MT = Motor Tanker or Motor Tug Boat - MV = Motor or Merchant Vessel - MY = Motor Yacht - NS = Nuclear Ship - RMS = Royal Mail Ship - RRS = Royal Research Ship - RV = Research Vessel - SS = Steam Ship - SV = Sailing Vessel (may be further coded by sailing type)

**Merchant Ship Categories** The UNCTAD review of maritime transport groups ships into: oil tankers, bulk (and combination) carriers, general cargo ships, container ships, and "other ships," which includes liquefied petroleum gas carriers, liquefied natural gas carriers, parcel (chemical) tankers, specialized tankers, reefers, offshore supply vessels, tugs, dredgers, cruise ships, ferries, and other non-cargo vessels. General cargo ships cover multi-purpose and project vessels as well as roll-on/roll-off cargo ships.

**Cargo Ship** A cargo ship, or freighter, is any vessel that carries cargo, goods, and materials from one port to another. Thousands of these ships travel the world's seas and oceans each year, handling most international trade. They are usually specially designed for the job, often with cranes and other loading and unloading gear, and come in all sizes.

**Bulk Carrier** A bulk carrier transports bulk cargo like iron ore, bauxite, coal, cement, grain, and similar items. These ships are recognizable by large box-like hatches on deck that slide outboard or fold fore-and-aft for loading or discharging cargo. Their dimensions are often set by the ports and sea routes they serve, as well as the maximum width of the Panama Canal. Most lakes are too small for bulk carriers, but a large fleet of lake freighters has operated on the Great Lakes and St. Lawrence Seaway of North America for over a century.

**Container Ship**

**Tanker** A tanker is a ship built to carry liquids in bulk. Tankers range from several hundred tons, serving small harbors and coastal settlements, to several hundred thousand tons, designed for long-range haulage. They carry a wide variety of products, including hydrocarbon products like oil, LPG, and LNG; chemicals such as ammonia, chlorine, and styrene monomer; fresh water; and wine. Different products require different handling and transport, leading to specialized types like chemical tankers, oil tankers, and gas carriers. Among oil tankers, supertankers were designed to carry oil around the Horn of Africa from the Middle East. The FSO *Knock Nevis*, formerly known as *Jahre Viking* (*Seawise Giant*), was the largest vessel in the world, with a deadweight of 565,000 metric tons and a length of about 458 meters. Using such large ships is actually very unprofitable because they cannot operate at full cargo capacity, so supertanker production has stopped. Today's largest oil tankers by gross tonnage are the TI-class supertankers *TI Europe*, *TI Asia*, and *TI Oceania*, which are the largest sailing vessels currently. Even with a deadweight of 441,585 metric tons, they usually sail as VLCCs and use no more than 70 percent of their total capacity. Apart from pipelines, tankers are the only way to transport large quantities of oil, though they have caused major environmental disasters when sinking near coastlines and causing oil spills, as seen with the *Braer*, *Erika*, *Exxon Valdez*, *Prestige*, and *Torrey Canyon*.

**Coastal Trading Vessel**

**Passenger Ship** A passenger ship is a vessel whose main purpose is carrying passengers. This category does not include cargo ships with limited passenger accommodations, like the once-common twelve-passenger freighters where passenger transport is secondary to freight. However, it does include many classes of ships designed to carry large numbers of passengers as well as freight.