The tags defined on this page will render in various nautical charts. This page defines values for the "seamark:type" tag for beacons and their category attribute tags.
A beacon is a prominent, specially constructed object forming a conspicuous mark as a fixed aid to navigation or for use in hydrographic surveys.
When top-marks, retro reflectors and/or lights are fitted to these marks, they are encoded as separate objects. Note that such top-marks are encoded as separate "topmark" (TOPMAR) objects). Beacons may also have lights and if such lights are fitted they are encoded as separate "light" (LIGHTS) objects.
Cardinal beacons are always painted in yellow and black horizontal bands and their distinctive double cone top-marks are always black.
More on Cardinal Marks: Seamarks/Cardinal_Marks
|Category (CATCAM)||beacon_cardinal:category||Definition|| seamark:beacon_cardinal:colour
|North||north||Quadrant bounded by the true bearing NW-NE taken from the point of interest it should be passed to the north side of the mark.||black;yellow||2 cones up|
|East||east||Quadrant bounded by the true bearing NE-SE taken from the point of interest it should be passed to the east side of the mark.||black;yellow;black||2 cones base together|
|South||south||Quadrant bounded by the true bearing SE-SW taken from the point of interest it should be passed to the south side of the mark.||yellow;black||2 cones down|
|West||west||Quadrant bounded by the true bearing SW-NW taken from the point of interest it should be passed to the west side of the mark.||yellow;black;yellow||2 cones point together|
Isolated Danger Beacons
There are no categories of Isolated Danger Beacons. The default colours and topmarks are:
There are two international buoyage regions, A and B, between which lateral marks differ. The buoyage region is encoded using the separate attribute "system" (MARSYS). Lateral beacons and their topmarks are always painted in red, green or red & green horizontal bands.
|Category (CATLAM)||beacon_lateral:category||Definition|| seamark:beacon_lateral:colour
|Port-hand Beacon||port||Indicates the port boundary of a navigational channel or suggested route when proceeding in the 'conventional direction of buoyage'.||IALA-A: red, IALA-B: green||cylinder|
|Starboard-hand Beacon||starboard||Indicates the starboard boundary of a navigational channel or suggested route when proceeding in the 'conventional direction of buoyage'.||IALA-A: green, IALA-B: red||cone, point up|
|Preferred Channel to Starboard Beacon||preferred_channel_starboard||At a point where a channel divides, when proceeding in the 'conventional direction of buoyage', the preferred channel (or primary route) is indicated by a modified port-hand lateral mark.||IALA-A: red;green;red, IALA-B: green;red;green||cylinder|
|Preferred Channel to Port Beacon||preferred_channel_port||At a point where a channel divides, when proceeding in the 'conventional direction of buoyage', the preferred channel (or primary route) is indicated by a modified starboard-hand lateral mark.||IALA-A: green;red;green, IALA-B: red;green;red||cone, point up|
|Inland Waterway Lateral Beacon||...||Many more categories of lateral marks are used in inland waterways. See: CEVNI Lateral Marks|
Safe Water Beacons
There are no categories of Safe Water Beacons. The default colours and topmarks are:
Special Purpose Beacons
Special purpose beacons can be any shape and are generally yellow in colour, with a variety of topmarks.
For "beacon_special_purpose:category" (CATSPM) definitions, see: Special Purpose Marks
Beacons can be painted in many different colours and colour patterns. See: Colours
Beacons may have other objects as part of their structure
|Topmark||TOPMAR||A characteristic shape secured at the top of a buoy or beacon to aid in its identification.||Topmarks|
|Light||LIGHTS||A luminous or lighted aid to navigation.||Lights|
|Fog Signal||FOGSIG||A warning signal transmitted by a vessel, or aid to navigation, during periods of low visibility. Also, the device producing such a signal.||Fog Signals|
|Radar transponder beacon||RTPBCN||A transponder beacon transmitting a coded signal on radar frequency, permitting an interrogating craft to determine the bearing and range of the transponder.||Radar Beacons|
|Radar Reflector||RADRFL||A device capable of, or intended for, reflecting radar signals.|