Index: > A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Home > Lateral mark

First Prev [ 1 2 ] Next Last

A lateral buoy, lateral post or lateral mark, as defined by the International Association of Lighthouse Authorities, is a sea mark used in maritime pilotage to indicate the edge of a channel.

Each mark indicates the direction of safe water in terms of port (left-hand) or starboard (right-hand). These directions are relative not only to the mark but also to the direction from which the mark is viewed; the interpretation is thus defined in terms of a vessel approaching in a nominally upstream direction. In a river, upstream is taken as leading towards the river's source; in a harbour, whether or not the harbour is fed by a river, a vessel entering the harbour is taken as moving upstream.

The interpretation of the marks is thus that a vessel heading upstream or entering a harbour:

keeps a port mark to its port (left), and
keeps a starboard mark to its right.

Marks are distinguished by their colour, being red or green, and shape. For historical reasons, two different schemes are in use worldwide, differing in their use of colour. The IALA defines them as System A and System B:

System B is used by nations in North America, Central America and South America, the Philippines, Japan and Korea.
System A is used by nations in Europe, AustraliaAustralia is the sixth-largest country in the world (geographically), the only one to occupy an entire continent, and the largest in the region of Australasia. Australia includes the island of Tasmania, which is an Australian State. Its neighbouring count, New ZealandFor alternative meanings, see New Zealand (disambiguation). New Zealand is a country formed of two major islands and a number of smaller islands in the southwestern Pacific Ocean. A common Mori name for New Zealand is Aotearoa popularly translated as Land, parts of AfricaAfrica is the world's second-largest continent in both area and population, after Asia. 30,244,050 km2 (11,677,240 mi2) including the islands, it covers 20. 3% of the total land area on Earth, and with over 800 million human inhabitants it accounts for ar and most of AsiaThe continent of Asia is defined by subtracting Europe and Africa from the great land mass of Africa-Eurasia. The boundaries are vague, especially between Asia and Europe: Asia and Africa meet somewhere near the Suez Canal. The boundary between Asia and E other than the Philippines, Japan and Korea.

In System A:

port marks are red and may have a red flashing light.
starboard marks are green and may have a green flashing light.

(Port) (left) (Red) _____________________________________ (Starboard) (right) (Green)

In System B:

port marks are green, and may have a green flashing light.
starboard marks are red and may have a red flashing light.

(Port) (left) (Green) _____________________________________ (Starboard) (right) (Red)

In both systems:

port marks are square or have a flat top
starboard marks are conical (or present a triangular shape) or have a pointed top.

The shape is an important feature, as colours cannot be distinguished in some conditions of direct sunlight, and by persons with red-green colour blindness. Marks may also carry unique markings of letters and numbers; these may be used to identify the mark as one indicated on a nautical chartA nautical chart is a graphic representation of a maritime area and adjacent coastal regions. It shows depths of water and heights of land, natural features of the seabed, details of the coastline, navigational hazards, locations of natural and man-made a. Likewise, a mark's light may flash in a distinctive sequence for the same purpose.

Also defined in the lateral mark systems is a bifurcation mark, which has both red and green horizontal bands, one over the other. This mark indicates that a "preferred" channel (often, a deep channel suitable for heavy commercial traffic) lies to one side, and a secondary channel on the other. Vessels wishing to use the preferred channel observe the top colour of the mark, and vessels wishing to use the secondary channel observe the bottom colour.

In System B only, the phrase "red right returning" may be used as a mnemonic, indicating that a red mark must be kept on the right when returning to (i.e., entering) a harbour or river.

The alternative system of cardinal marksA cardinal mark as defined by the International Association of Lighthouse Authorities, is a sea mark (a buoy or other floating or fixed structure) used in maritime pilotage to indicate the position of a hazard and the direction of safe water. They are int is used where there is no clear upstream reference direction.

Politics	Business	Finance

Topics: Lateral Mark Marks Red System Port Green Starboard Channel...

Lateral passAmerican football In American football and Canadian football a lateral pass — usually called simply a lateral — is an intentional throwing of the football by a member of the team in possession of same, to or toward a player on the same team who is no clos	Lateral consonantLaterals are "L"-like consonants pronounced with an occlusion made somewhere along the axis of the tongue, while air from the lungs escapes at one side or both sides of the tongue. Most commonly the tip of the tongue makes contact with the upper teeth (se	LateralThe term lateral can refer to: an anatomical definition of direction. See Terms for anatomical location lateral consonants a lateral pass in American football.
LateralusIn 2001 (see 2001 in music), Tool released their third studio album, Lateralus . The album was a commercial success, reaching the #1 position on the Billboard charts in its premiere week. Two music videos were released: "Schism" (the video had a short amb	Lateral thinkingLateral thinking is a term invented by Edward de Bono. He defines it as a technique of problem solving by approaching problems indirectly at diverse angles instead of concentrating on one approach at length. For example: It took two hours for two men to d	Lateral ThinkingLateral Thinking is a book by Edward De Bono, published in 1970. See also lateral thinking (that article's title is distinguished from this one's by a lower-case "t").
Lateral geniculate nucleus	Lateral mark	Lateral alveolar approximant
Lateral alveolar click	Lateral alveolar flap	Lateral palatal approximant
Lateral retroflex approximant	Lateral velar approximant	Lateral voiced alveolar fricative

Non User