
Port and starboard are
nautical
Seamanship is the art, knowledge and competence 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 topics an ...
terms for
watercraft
Any vehicle used in or on water as well as underwater, including boats, ships, hovercraft and submarines, is a watercraft, also known as a water vessel or waterborne vessel. A watercraft usually has a propulsive capability (whether by sail ...
and
aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. ...
, referring respectively to the left and right sides of the vessel, when aboard and facing the
bow (front).
Vessels with bilateral
symmetry have left and right halves which are
mirror image
A mirror image (in a plane mirror) is a reflected duplication of an object that appears almost identical, but is reversed in the direction perpendicular to the mirror surface. As an optical effect it results from reflection off from substances ...
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 and starboard unambiguously refer to the left and right side of the vessel, not the observer. That is, the port side of the vessel always refers to the same portion of the vessel's structure, and does not depend on
which way the observer is facing.
The port side is the side of the vessel which is to the left of an observer aboard the vessel and , that is, facing forward towards the direction the
vehicle
A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles ( motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles ( trains, trams ...
is heading when
underway, and starboard side is to the right of such an observer.
This convention allows orders and information to be given unambiguously, without needing to know which way any particular crew member is facing.
Etymology

The term ''starboard'' derives from the
Old English ''steorbord'', meaning the side on which the ship is steered. Before ships had
rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adverse yaw a ...
s on their centrelines, they were steered with a
steering oar
The steering oar or steering board is an over-sized oar or board, to control the direction of a ship or other watercraft prior to the invention of the rudder.
It is normally attached to the starboard
Port and starboard are nautical ter ...
at the
stern
The stern is the back or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite the bow, the foremost part of a ship. Ori ...
of the ship 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 it being stronger, faster or more dextrous. The other hand, comparatively often the weaker, less dextrous or simply less subjecti ...
.
The "steer-board" etymology is shared by the
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
''Steuerbord,''
Dutch
Dutch commonly refers to:
* Something of, from, or related to the Netherlands
* Dutch people ()
* Dutch language ()
Dutch may also refer to:
Places
* Dutch, West Virginia, a community in the United States
* Pennsylvania Dutch Country
People E ...
''stuurboord'' and
Swedish
Swedish or ' may refer to:
Anything from or related to Sweden, a country in Northern Europe. Or, specifically:
* Swedish language, a North Germanic language spoken primarily in Sweden and Finland
** Swedish alphabet, the official alphabet used b ...
''styrbord'', which gave rise to the
French
French (french: français(e), link=no) may refer to:
* Something of, from, or related to France
** French language, which originated in France, and its various dialects and accents
** French people, a nation and ethnic group identified with France ...
''tribord'',
Italian
Italian(s) may refer to:
* Anything of, from, or related to the people of Italy over the centuries
** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom
** Italian language, a Romance language
*** Regional Ita ...
''tribordo,''
Catalan
Catalan may refer to:
Catalonia
From, or related to Catalonia:
* Catalan language, a Romance language
* Catalans, an ethnic group formed by the people from, or with origins in, Northern or southern Catalonia
Places
* 13178 Catalan, asteroid ...
''estribord'',
Portuguese
Portuguese may refer to:
* anything of, from, or related to the country and nation of Portugal
** Portuguese cuisine, traditional foods
** Portuguese language, a Romance language
*** Portuguese dialects, variants of the Portuguese language
** Port ...
''estibordo'', Spanish ''estribor'' and
Estonian ''tüürpoord''.
Since the steering oar was on the right side of the boat, it would tie up at the
wharf
A wharf, quay (, also ), staith, or staithe is a structure on the shore of a harbour or on the bank of a river or canal where ships may dock to load and unload cargo or passengers. Such a structure includes one or more Berth (moorings), berths ...
on the other side. Hence the left side was called ''port''. The ''
Oxford English Dictionary
The ''Oxford English Dictionary'' (''OED'') is the first and foundational historical dictionary of the English language, published by Oxford University Press (OUP). It traces the historical development of the English language, providing a com ...
'' cites ''port'' in this usage since 1543.
Formerly, ''larboard'' was often used instead of ''port''. This is 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 ...
''ladebord'' and the term ''lade'' is related to the modern ''load''.
[ ''Larboard'' sounds similar to ''starboard'' and in 1844 the ]Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by Kingdom of England, English and Kingdom of Scotland, Scottish kings from the early medieval period, the first major maritime engagements were foug ...
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'' was used 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
''The Hunting of the Snark'', subtitled ''An Agony in 8 Fits'', is a poem by the English writer Lewis Carroll. It is typically categorised as a nonsense poem. Written between 1874 and 1876, it borrows the setting, some creatures, and eight po ...
'' (1876).
An Anglo-Saxon record of a voyage by Ohthere of Hålogaland
Ohthere of Hålogaland ( no, Ottar fra Hålogaland) was a Viking Age Norwegian seafarer known only from an account of his travels that he gave to King Alfred (r. 871–99) of the Anglo-Saxon kingdom of Wessex in about 890 AD. His account ...
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 bagbord (Nordic for portside) side of the ship. The words for "port side" in other European languages, such as German ''Backbord'', Dutch and Afrikaans ''bakboord'', Swedish ''babord'', Spanish ''babor'', Portuguese '' bombordo'', Italian ''babordo'', French ''bâbord'' and Estonian ''pakpoord'', are derived from the same root.
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 (COLREGs) are published by the International Maritime Organization (IMO) and set out, among other things, the "rules of the road" or navigation rules to be followed by ships a ...
—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
The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the United States Armed Forces and one of the country's eight uniformed services. The service is a maritime, military, mu ...
)—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
''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...
'' 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-coded ...
s, the vessel's starboard side by green and its port side by red.[ ]Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. ...
are lit in the same way.
See also
* Anatomical terms of location
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position ...
, another example of terms of directionality that do not depend on the location of the observer for things that are bilaterally symmetrical
* Dexter and sinister
''Dexter'' and ''sinister'' are terms used in heraldry to refer to specific locations in an escutcheon bearing a coat of arms, and to the other elements of an achievement. ''Dexter'' (Latin for 'right') indicates the right-hand side of the shie ...
* Direction (disambiguation)
Direction may refer to:
*Relative direction, for instance left, right, forward, backwards, up, and down
** Anatomical terms of location for those used in anatomy
** List of ship directions
*Cardinal direction
Mathematics and science
* Directi ...
* Glossary of nautical terms
This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water (mostly though not necessarily on the sea). Some remain current, while many date from the 17th ...
* Handedness
In human biology, handedness is an individual's preferential use of one hand, known as the dominant hand, due to it being stronger, faster or more dextrous. The other hand, comparatively often the weaker, less dextrous or simply less subjec ...
* Laterality
The term laterality refers to the preference most humans show for one side of their body over the other. Examples include left-handedness/right-handedness and left/right-footedness; it may also refer to the primary use of the left or right hem ...
* Proper right and proper left
Proper right and proper left are conceptual terms used to unambiguously convey relative direction when describing an image or other object. The "proper right" hand of a figure is the hand that would be regarded by that figure as its right hand. ...
* Reflection symmetry
In mathematics, reflection symmetry, line symmetry, mirror symmetry, or mirror-image symmetry is symmetry with respect to a reflection. That is, a figure which does not change upon undergoing a reflection has reflectional symmetry.
In 2D the ...
* Sinistral and dextral
Sinistral and dextral, in some scientific fields, are the two types of chirality ("handedness") or relative direction. The terms are derived from the Latin words for "left" (''sinister'') and "right" (''dexter''). Other disciplines use different ...
Notes
References
{{Aircraft components, state=collapsed
Aeronautics
Nautical terminology
Orientation (geometry)