Editing Ship (section)

=== Merchant ship ===
{{Main|Merchant ship}}

[[File:Container ships President Truman (IMO 8616283) and President Kennedy (IMO 8616295) at San Francisco.jpg|thumb|Two modern [[container ship]]s in [[San Francisco]]]]

[[Merchant ship]]s are ships used for commercial purposes and can be divided into four broad categories: [[fishing vessels]], [[cargo ship]]s, [[passenger ship]]s, and special-purpose ships.<ref>UNCTAD 2007, p.&nbsp;xii uses a similar, but slightly more detailed classification system.</ref> The [[UNCTAD review of maritime transport]] categorizes ships as: 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, [[Reefer ship|reefer]]s, offshore supply, tugs, [[dredger]]s, [[Cruise ship|cruise]], [[Ferry|ferries]], other non-cargo". General cargo ships include "multi-purpose and project vessels and roll-on/roll-off cargo".<ref name="UNCTAD" />

Modern commercial vessels are typically powered by a single propeller driven by a [[diesel engine|diesel]] or, less usually, [[gas turbine engine]].,<ref>{{Cite web|url=https://www.marineinsight.com/main-engine/different-types-of-marine-propulsion-systems-used-in-the-shipping-world/|website=www.marineinsight.com|access-date=2020-05-14|title=Different Types of Marine Propulsion Systems Used in the Shipping World|date=25 August 2019}}</ref> but until the mid-19th century they were predominantly square sail rigged. The fastest vessels may use [[pump-jet engine]]s.{{Citation needed|date=April 2008}} Most commercial vessels such as container ships, have full hull-forms (higher [[Block coefficient]]s) to maximize cargo capacity.<ref name="Witherby">{{cite book | title=21st century seamanship | publisher=[[Witherby Publishing Group]] | publication-place=Livingston | date=2015 | isbn=978-1-85609-632-4 | page=38}}</ref> Merchant ships and fishing vessels are usually made of steel, although aluminum can be used on faster craft, and fiberglass or wood on smaller vessels.<ref name="Witherby434">{{cite book | title=21st century seamanship | publisher=[[Witherby Publishing Group]] | publication-place=Livingston | date=2015 | isbn=978-1-85609-632-4 | page=434}}</ref>  Commercial vessels generally have a crew headed by a [[sea captain]], with [[deck officer]]s and [[engine officer]]s on larger vessels. Special-purpose vessels often have specialized crew if necessary, for example scientists aboard [[research vessel]]s.

Fishing boats are generally small, often little more than {{convert|30|m|ft|sp=us}} but up to {{convert|100|m|ft}} for a large tuna or [[whaling ship]]. Aboard a [[fish processing vessel]], the catch can be made ready for market and sold more quickly once the ship makes port. Special purpose vessels have special gear. For example, trawlers have winches and arms, stern-trawlers have a rear ramp, and tuna seiners have skiffs. In 2004, {{convert|85800000|t|LT ST|sigfig=3|lk=on}} of fish were caught in the marine capture fishery.<ref name="fao11">UNFAO, 2007, p. 11.</ref> [[Anchoveta]] represented the largest single catch at {{convert|10700000|t|LT ST|sigfig=3}}.<ref name="fao11" />  That year, the top ten marine capture species also included [[Alaska pollock]], [[Blue whiting]], [[Skipjack tuna]], [[Atlantic herring]], [[Chub mackerel]], [[Anchovy|Japanese anchovy]], [[Trachurus|Chilean jack mackerel]], [[Largehead hairtail]], and [[Yellowfin tuna]].<ref name="fao11" />  Other species including [[salmon]], [[shrimp]], [[lobster]], [[clam]]s, [[squid]] and [[crab]], are also commercially fished. Modern commercial fishermen use many methods. One is fishing by [[Fishing net|nets]], such as [[Seine fishing|purse seine]], beach seine, lift nets, [[gillnet]]s, or entangling nets. Another is [[trawl]]ing, including [[Bottom trawling|bottom trawl]]. [[Fish hook|Hooks]] and lines are used in methods like [[long-line fishing]] and [[hand-line fishing]]. Another method is the use of [[fishing trap]].

Cargo ships transport dry and liquid cargo. Dry cargo can be transported in bulk by [[bulk carrier]]s, packed directly onto a [[general cargo ship]] in break-bulk, packed in [[intermodal container]]s as aboard a [[container ship]], or driven aboard as in [[roll-on roll-off ship]]s. Liquid cargo is generally carried in bulk aboard tankers, such as [[oil tanker]]s which may include both crude and finished products of oil, [[chemical tanker]]s which may also carry vegetable oils other than chemicals and [[gas carrier]]s, although smaller shipments may be carried on container ships in [[tank container]]s.<ref name="Gubbins" />

[[Passenger ship]]s range in size from small river ferries to very large [[cruise ship]]s. This type of vessel includes [[ferry|ferries]], which move passengers and vehicles on short trips; [[ocean liner]]s, which carry passengers from one place to another; and [[cruise ship]]s, which carry passengers on voyages undertaken for pleasure, visiting several places and with leisure activities on board, often returning them to the port of embarkation. [[Riverboat]]s and [[ferry boat|inland ferries]] are specially designed to carry passengers, cargo, or both in the challenging river environment. Rivers present special hazards to vessels. They usually have varying water flows that alternately lead to high speed water flows or protruding rock hazards. Changing siltation patterns may cause the sudden appearance of shoal waters, and often floating or sunken logs and trees (called snags) can endanger the hulls and propulsion of riverboats. Riverboats are generally of shallow draft, being broad of beam and rather square in plan, with a low freeboard and high topsides. Riverboats can survive with this type of configuration as they do not have to withstand the high winds or large waves that are seen on large lakes, seas, or oceans.

[[File:Albatun Dod.jpg|thumb|''Albatun Dos'', a tuna boat at work near [[Victoria, Seychelles]]]]

[[Fishing vessel]]s are a subset of commercial vessels, but generally small in size and often subject to different regulations and classification. They can be categorized by several criteria: architecture, the type of fish they catch, the fishing method used, geographical origin, and technical features such as rigging. As of 2004, the world's fishing fleet consisted of some 4 million vessels.<ref name="fao25">UNFAO, 2007, p. 25.</ref>  Of these, 1.3 million were decked vessels with enclosed areas and the rest were open vessels.<ref name="fao25" />  Most decked vessels were mechanized, but two-thirds of the open vessels were traditional craft propelled by sails and oars.<ref name="fao25" />  More than 60% of all existing large fishing vessels{{efn|UNFAO defines a large fishing vessel as one with [[gross tonnage]] over 100 GT.}} were built in Japan, Peru, the Russian Federation, Spain or the United States of America.<ref>UNFAO, 2007, p. 28.</ref>