This page defines values for the seamark:type=* key for buoys and their category attribute tags. These tags may be used in various nautical charts.
A buoy is a floating object moored to the bottom in a particular place, as an aid to navigation or other specific purposes.
|Type||S100 Code||seamark:type||Definition||Example renderings||Photo|
|Cardinal buoy||BOYCAR||buoy_cardinal||A cardinal buoy 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.|
|Installation buoy||BOYINB||buoy_installation||An installation buoy is a buoy used for loading tankers with gas or oil.|
|Isolated danger buoy||BOYISD||buoy_isolated_danger||A isolated danger buoy is a buoy moored on or above an isolated danger of limited extent, which has navigable water all around it.|
|Lateral buoy||BOYLAT||buoy_lateral||A lateral buoy 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.|
|Mooring buoy||MORFAC||mooring||See: Moorings|
|Safe water buoy||BOYSAW||buoy_safe_water||A safe water buoy is used to indicate that there is navigable water around the mark.|
|Special purpose buoy||BOYSPP||buoy_special_purpose||A special purpose buoy 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). Buoy in general: A buoy whose appearance or purpose is not adequately known.|
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). Buoys may also have lights and if such lights are fitted they are encoded as separate "light" (LIGHTS) objects.
- Main article: OpenSeaMap/cardinal marks
Cardinal buoys do not have a distinctive shape but are normally pillar or spar. They are always painted in yellow and black horizontal bands and their distinctive double cone top-marks are always black. The tags seamark:buoy_cardinal:colour_pattern=horizontal and seamark:topmark:colour=black are used regardless of cardinal direction.
|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|
|Catenary anchor leg mooring||calm||Incorporates a large buoy which remains on the surface at all times and is moored by 4 or more anchors. Mooring hawsers and cargo hoses lead from a turntable on top of the buoy, so that the buoy does not turn as the ship swings to wind and stream.|
|Single buoy mooring||sbm||A mooring structure used by tankers to load and unload in port approaches or in offshore oil and gas fields.|
Isolated danger buoys
There are no categories of isolated danger buoys. The default colours and topmarks are:
- seamark:topmark:shape=2 spheres
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 buoys generally have distinctive shapes (can for port-hand, conical for starboard-hand) or may be a pillar or spar with distinctive topmarks. The buoys and their topmarks are always painted in red, green or red & green horizontal bands.
|Port-hand buoy||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|
|Preferred channel to port buoy||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|
|Starboard-hand buoy||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 buoy||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|
|Inland waterway lateral buoy||...||Many more categories of lateral marks are used in inland waterways. See: CEVNI lateral marks|
Safe water buoys
There are no categories of safe water buoys. The default colours and topmarks are:
Special purpose buoys
Special purpose buoys can be any shape and are generally yellow in colour, with a variety of topmarks.
For "buoy_special_purpose:category" (CATSPM) definitions, see: special purpose marks.
|Conical (nun, ogival)||conical||The upper part of the body above the water-line, or the greater part of the superstructure, has approximately the shape or the appearance of a pointed cone with the point upwards.|
|Can (cylindrical)||can||The upper part of the body above the water-line, or the greater part of the superstructure, has the shape of a cylinder, or a truncated cone that approximates to a cylinder, with a flat end uppermost.|
|Spherical||spherical||The upper part of the body above the water-line, or the greater part of the superstructure, has the shape of a part of a sphere.|
|Pillar||pillar||The upper part of the body above the water-line, or the greater part of the superstructure is a narrow vertical structure, pillar or lattice tower.|
|Spar (spindle)||spar||The upper part of the body above the water-line, or the greater part of the superstructure, has the form of a pole, or of a very long cylinder, floating upright.|
|Barrel (tun)||barrel||The upper part of the body above the water-line, or the greater part of the superstructure, has the form of a barrel or cylinder floating horizontally.|
|Super-buoy||super-buoy||A very large buoy, generally more than 5m in diameter.|
|Ice buoy||ice_buoy||A specially constructed shuttle shaped buoy which is used in ice conditions.||File:Buoy Ice.png|
Buoys can painted in many different colours and colour patterns. See: colours.
Buoys may have other objects as part of their structure
|Topmarks||TOPMAR||A characteristic shape secured at the top of a buoy or beacon to aid in its identification.|
|Lights||LIGHTS||A luminous or lighted aid to navigation.|
|Fog signals||FOGSIG||A warning signal transmitted by a vessel, or aid to navigation, during periods of low visibility. Also, the device producing such a signal.|
|Radar transponder beacons||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 reflector||RADRFL||A device capable of, or intended for, reflecting radar signals.|
OSM seamark resources
- Seamark tag values(en)
- Seamark objects(en)
- Seamark attributes(en)
- Categories of objects(en)
- INT-1 cross reference(en)
- Inland waterway notice marks (CEVNI)(en)
- Inland waterway lateral marks (CEVNI)(en)
- S-101 ENC/iENC registry (iho.int), the ENC Data Classification and Encoding Guide (DCEG) can be downloaded as zipped PDF, online access to symbols in Portrayal Register
- International nautical chart symbol legend (Chart INT-1, NOAA)
- Encoding Guide for Inland ENCs (openecdis.org, 2018), an international standard of the Inland ENC Harmonization Group is currently in development (IEHG Publication S-401, 2019)
- European Code for Inland Waterways (CEVNI), (UNECE, Fifth revised version 2015)
- European Code for Signs and Signals on Inland Waterways (SIGNI), (UNECE Resolution N0. 90, 2018)
- U.S. Aids to Navigation System – also details the Western Waters Marking System, Intracoastal Waterway system, and Uniform State Waterway Marking System