Port and starboard are

nautical Seamanship is the art, competence, and knowledge of operating a ship, boat or other craft on water. The'' Oxford Dictionary'' states that seamanship is "The skill, techniques, or practice of handling a ship or boat at sea." It involves topic ...

terms for

watercraft A watercraft or waterborne vessel is any vehicle designed for travel across or through water bodies, such as a boat, ship, hovercraft, submersible or submarine. Types Historically, watercraft have been divided into two main categories. *Raf ...

and

spacecraft A spacecraft is a vehicle that is designed spaceflight, to fly and operate in outer space. Spacecraft are used for a variety of purposes, including Telecommunications, communications, Earth observation satellite, Earth observation, Weather s ...

, referring respectively to the left and right sides of the vessel, when aboard and facing the bow (front). Vessels with bilateral

symmetry Symmetry () in everyday life refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is Invariant (mathematics), invariant und ...

have left and right halves which are

mirror image A mirror image (in a plane mirror) is a reflection (physics), reflected duplication of an object that appears almost identical, but is reversed in the direction perpendicular to the mirror surface. As an optical phenomenon, optical effect, it r ...

s of each other. One asymmetric feature is where access to a boat, ship, or aircraft is at the side; it is usually only on the port side (hence the name).

Side

Port side and starboard side respectively refer to the left and right sides of the vessel, when aboard and facing the bow. The port and starboard sides of the vessel always refer to the same portion of the vessel's structure, and do not depend on the position of someone aboard the vessel. The port side is the side to the left of an observer aboard the vessel and , towards the direction the vessel is heading when

underway Underway, or under way, is a nautical term describing the state of a vessel which is unconstrained from horizontal translational movement relative to the water and the ground. "Way" arises when there is sufficient water flow past the rudder of a ...

in the forward direction. The starboard side is to the right of such an observer. This convention allows orders and information to be communicated unambiguously, without needing to know which way any particular crew member is facing.

Etymology

The term ''starboard'' derives from the

Old English Old English ( or , or ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the Early Middle Ages. It developed from the languages brought to Great Britain by Anglo-S ...

''steorbord'', ''steor'' meaning steer, and ''bord'' meaning side. Before ships had

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw ...

s, they were steered with a steering oar on the right hand side of the ship, because more people are

right-handed In human biology, handedness is an individual's preferential use of one hand, known as the dominant hand, due to and causing it to be stronger, faster or more Fine motor skill, dextrous. The other hand, comparatively often the weaker, less dext ...

. The "steer-board" etymology is shared by the German ''Steuerbord,'' Dutch ''stuurboord'', Icelandic ''stjórnborði'' and Swedish / Danish / Norwegian ''styrbord'', which gave rise to the French ''tribord'',

Italian Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, a Romance ethnic group related to or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance languag ...

''tribordo,'' Catalan ''estribord'', Portuguese ''estibordo'', Spanish ''estribor'' and

Estonian Estonian may refer to: * Something of, from, or related to Estonia, a country in the Baltic region in northern Europe * Estonians, people from Estonia, or of Estonian descent * Estonian language * Estonian cuisine * Estonian culture See also

...

''tüürpoord''. Since the steering oar was on the right side of the boat, it would dock on the left side. In Old English, this side was known as ''bæcbord.'' An Anglo-Saxon record of a voyage by Ohthere of Hålogaland used the word "bæcbord" ("back-board") for the left side of a ship. With the steering rudder on the starboard side the man on the rudder had his back to the left side of ship. German ''Backbord'', Dutch ''bakboord'', Icelandic ''bakborði'', Swedish ''babord'', Spanish ''babor'', Portuguese'' bombordo'', Italian ''babordo'', French ''bâbord'', and Estonian ''pakpoord'', are all

cognate In historical linguistics, cognates or lexical cognates are sets of words that have been inherited in direct descent from an etymological ancestor in a common parent language. Because language change can have radical effects on both the s ...

. From around 1300 the term ''ladde-borde'' was used, from

Middle English Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman Conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English pe ...

''ladebord'', ''lade'' meaning load, and ''bord'' meaning side. ''Ladebord'' was changed to ''larboard'' in the 1500s, possibly by association with starboard. This side was also called ''port'', since it was the docking side. The ''

Oxford English Dictionary The ''Oxford English Dictionary'' (''OED'') is the principal historical dictionary of the English language, published by Oxford University Press (OUP), a University of Oxford publishing house. The dictionary, which published its first editio ...

'' cites this usage since 1543. ''Larboard'' sounds similar to ''starboard'' and in 1844 the

Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...

ordered that ''port'' be used instead. The United States Navy followed suit in 1846. ''Larboard'' continued to be used well into the 1850s by

whaler A whaler or whaling ship is a specialized vessel, designed or adapted for whaling: the catching or processing of whales. Terminology The term ''whaler'' is mostly historic. A handful of nations continue with industrial whaling, and one, Jap ...

s. In chapter 12 of ''Life on the Mississippi'' (1883) Mark Twain writes ''larboard'' to refer to the left side of the ship ( Mississippi River steamboat) in his days on the river – circa 1857–1861. Lewis Carroll rhymed ''larboard'' and ''starboard'' in "Fit the Second" of '' The Hunting of the Snark'' (1876).

Importance of standard terms

The navigational treaty convention, the

International Regulations for Preventing Collisions at Sea The International Regulations for Preventing Collisions at Sea 1972, also known as ''Collision Regulations'' (''COLREGs''), are published by the International Maritime Organization (IMO) and set out, among other things, the "rules of the road" o ...

—for instance, as appears in the UK's Merchant Shipping (Distress Signals and Prevention of Collisions) Regulations 1996 (and comparable US documents from the US Coast Guard)—sets forth requirements for maritime vessels to avoid collisions, whether by sail or powered, and whether a vessel is overtaking, approaching head-on, or crossing. To set forth these navigational rules, the terms starboard and port are essential, and to aid in ''

in situ is a Latin phrase meaning 'in place' or 'on site', derived from ' ('in') and ' ( ablative of ''situs'', ). The term typically refers to the examination or occurrence of a process within its original context, without relocation. The term is use ...

'' decision-making, the two sides of each vessel are marked, dusk to dawn, by

navigation light A navigation light, also known as a running or position light, is a source of illumination on a watercraft, aircraft or spacecraft, meant to give information on the craft's position, heading, or status. Some navigation lights are colour-code ...

s, the vessel's starboard side by green and its port side by red.

Aircraft An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, i ...

are lit in the same way.

Other nautical uses

Port and starboard are also commonly used when dividing crews; for example with a two

watch A watch is a timepiece carried or worn by a person. It is designed to maintain a consistent movement despite the motions caused by the person's activities. A wristwatch is worn around the wrist, attached by a watch strap or another type of ...

system the teams supplying the personnel are often named Port and Starboard. This may extend to entire crews, such as the forward-deployed crews of the Royal Navy’s

Gulf A gulf is a large inlet from an ocean or their seas into a landmass, larger and typically (though not always) with a narrower opening than a bay (geography), bay. The term was used traditionally for large, highly indented navigable bodies of s ...

-based frigate, or

ballistic missile submarines A ballistic missile submarine is a submarine capable of deploying submarine-launched ballistic missiles (SLBMs) with nuclear warheads. These submarines became a major weapon system in the Cold War because of their deterrence theory, nuclear ...

Notes

References

{{Aircraft components, state=collapsed Aeronautics Nautical terminology Orientation (geometry)