Seamarks/Beacons
Contents
Beacon
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.
Types
A beacon is a prominent, specially constructed object forming a conspicuous mark as a fixed aid to navigation or for use in hydrographic surveys.
| Type | S100 Code | seamark:type | Definition | Example Renderings | Photo |
|---|---|---|---|---|---|
| Cardinal Beacon | BCNCAR | beacon_cardinal | A cardinal beacon is used in conjunction with the compass to indicate where the mariner may find the best navigable water. It is placed in one of the four quadrants (North, East, South and West), bounded by inter-cardinal bearings from the point marked. | 
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| Isolated Danger Beacon | BCNISD | beacon_isolated_danger | An isolated danger beacon is a beacon erected on an isolated danger of limited extent, which has navigable water all around it. | 
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| Lateral Beacon | BCNLAT | beacon_lateral | A lateral beacon is used to indicate the port or starboard hand side of the route to be followed. They are generally used for well defined channels and are used in conjunction with a conventional direction of buoyage. | 
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| Safe Water Beacon | BCNINB | beacon_safe_water | A safe water beacon is a prominent specially constructed object forming a conspicuous mark as a fixed aid to navigation or for use in hydrographic surveys. | 
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| Special Purpose Beacon | BCNSPP | beacon_special_purpose | A special purpose beacon is primarily used to indicate an area or feature, the nature of which is apparent from reference to a chart, Sailing Directions or Notices to Mariners (UKHO NP 735, 5th Edition). Beacon in general: A beacon whose appearance or purpose is not adequately known. | 
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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.
Categories
Cardinal Beacons
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
(seamark:beacon_cardinal:colour_pattern=horizontal) |
seamark:topmark:shape
(seamark:topmark:colour=black) |
|---|---|---|---|---|
| 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:
| seamark:beacon_isolated_danger:colour | seamark:beacon_isolated_danger:colour_pattern | seamark:topmark:shape | seamark:topmark:colour |
|---|---|---|---|
| black;red;black | horizontal | 2 spheres | black |
Lateral Beacons
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
[seamark:beacon_lateral:colour_pattern=horizontal] |
seamark:topmark:shape |
|---|---|---|---|---|
| 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:
| seamark:beacon_safe_water:colour | seamark:beacon_safe_water:colour_pattern | seamark:topmark:shape | seamark:topmark:colour |
|---|---|---|---|
| red;white | vertical | sphere | red |
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
Shapes
| Shape (BCNSHP) | seamark:<beacon_type>:shape | Definition | Rendering |
|---|---|---|---|
| Stake, Pole, Perch or Post | stake pole perch post |
An elongated wood or metal pole, embedded in the bottom to serve as a navigational aid or a support for a navigational aid. | 
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| Withy | withy | A tree without roots stuck or spoiled into the bottom of the sea to serve as a navigational aid. | 
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| Beacon tower | tower | A solid structure of the order of 10 metres in height used as a navigational aid. | 
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| Pile beacon | pile | A long heavy timber(s) or section(s) of steel, wood, concrete, etc., forced into the seabed to serve as an aid to navigation or as a support for an aid to navigation. | 
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| Lattice beacon | lattice | A structure consisting of strips of metal or wood crossed or interlaced to form a structure to serve as an aid to navigation or as a support for an aid to navigation. |
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| Cairn | cairn | A mound of stones, usually conical or pyramidal, raised specifically for maritime navigation. | 
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| Buoyant beacon | buoyant | A tall spar-like beacon fitted with a permanently submerged buoyancy chamber, the lower end of the body is secured to seabed sinker either by a flexible joint or by a cable under tension. |
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Colours
Beacons can be painted in many different colours and colour patterns. See: Colours
Other Objects
Beacons may have other objects as part of their structure
| Object | S100 | Definition | Wiki page |
|---|---|---|---|
| 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 |
| Radio Station | RDOSTA | A place equipped to transmit radio waves. | Radio Stations |
| Radar Reflector | RADRFL | A device capable of, or intended for, reflecting radar signals. |
References
Seamark Tag Values
Seamark Objects
Seamark Attributes
INT-1 Cross Reference
