Chart symbols

The seafaring nations of the world - members of the International Hydrographic Organization - agreed in 1982 on an universal set of chart symbols, abbreviations, colours, etc to be used in the nautical chart, in order to obtain uniformity.

On regular charts a white, red, yellow or green lights will be indicated by , and on GPS displays and modern multi-coloured charts in specific colours: , with the yellow coloured lobe indicating a white light.
The precise position of a chart symbol is its center, or is indicated with a line and circle , the “position circle”.

Two distinct types of sea mark are drawn differently in the chart:

beacons - fixed to the seabed; drawn upright;

buoys - consisting of a floating object that is usually anchored to a specific location on the sea floor; drawn at an oblique angle and with oblique numbering, descriptions of colours and light characteristics.

	Major floating light (light-vessel, major light-float, LANBY)
	Light-vessel
	Major light; minor light
	Green or black buoys (symbols filled black): G = Green; B = Black
	Green or black beacon (symbol filled black). Note the upright G, instead of an oblique G
	Single coloured buoys other than green and black: Y = Yellow; R = Red
	Coloured beacon other than green and black, the symbol is again filled black so only the shape of the topmark is of navigational significance.
	Multiple colours in horizontal bands, the colour sequence is from top to bottom
	Multiple colours in vertical or diagonal stripes, the darker colour is given first. W = White
	Spar buoy (here a safe water mark)
	Lighted marks on multi-coloured charts, GPS displays and chart plotters.
	Lighted red beacon on standard charts.
	Red beacon and green buoy with topmark, colour, radar reflector and designation. Red buoys and marks are given even numbers, green buoys and marks are given odd numbers.
	Wave-actuated bell buoy to the left, and to the right a Light buoy, with a horn giving a single blast every 15 seconds, in conjunction with a wave-actuated whistle. Other sounds include “Gong”, “Siren”, “Diaphone” (Dia). The fog signal symbol may be omitted when a description of the signal is given.
	Leading beacons - Leading line (firm line is the track to be followed)
	Leading lights (≠: any two objects in line under each other). Bearing given in degrees and minutes. The lights are synchronized. The red light has a shorter nominal range (the distance from which the light can be seen): 10 nautical miles.
	All-round light with obscured sector
	Sector light on multi-coloured charts. The elevation is 21 metres (height of the light structure above chart datum). The nominal range of the white light is 18 nautical miles. The range of the green and red light is 12 nautical miles.
	Main light visible all-round with red subsidiary light seen over danger. The fixed red light has an elevation of 55 metres and a nominal range of 12 nautical miles. The flashing light is white, with three flashes in a period of 10 seconds. The elevation is higher than the red light: 62 metres and the range of the white light is 25 nautical miles.
	Symbol showing direction of buoyage (where not obvious)
	Symbol showing direction of buoyage (where not obvious), on multi-coloured charts (red and green circles coloured as appropriate), here IALA A

Full example of a light description in the chart:

Fl(3)WRG.15s21m15-11M
Class of light: group flashing repeating a group of three flashes;
Colours: white, red, green, exhibiting the different colours in defined sectors;
Period: the time taken to exhibit one full sequence of 3 flashes and eclipses: 15 seconds;
Elevation of light: 21 metres;
Nominal range(s): white 15 M, green 11 M, red between 15 and 11 M, where “M” stands for nautical miles.

Дата добавления: 2015-12-07