View source for Buoy

{{Short description|Floating structure or device}}
{{About||the French commune|Bouy|the Norwegian island|Buøy|other uses}}
[[File:Lateral Buoy.jpg|thumb|x250px|Buoy [[Solar panel|solar panels]] and [[LED light]]]]
{{multiple image
   | image1    = Canbuoy11.jpg
   | width1    = 165
   | alt1      = Green Can #11
   | caption1  = Green can #11 near the mouth of the [[Saugatuck River]] (IALA region B).
   | image2    = Can_11_in_Saugatuck_river.jpg
   | width2    = 88
   | alt2      = Green Can #11 on Map
   | caption2  = Green Can #11 on a [[nautical chart]] 
  }}
[[File:NOAA-NDBC-discus-buoy.jpg|thumb|upright|[[NOAA]] [[Weather buoy]]]]

A '''buoy''' ({{IPAc-en|ˈ|b|uː|.|i|,_|b|ɔɪ}}; {{respell|BOO|ee|,_|boy}})<ref>{{cite Dictionary.com|buoy}}</ref><ref>{{cite American Heritage Dictionary|buoy}}</ref> is a [[buoyancy|float]]ing device that can have many purposes. It can be [[anchor]]ed (stationary) or allowed to drift with ocean currents.

==Types==

===Navigational buoys===
* '''Race course marker buoys''' are used for buoy racing, the most prevalent form of [[yacht racing]] and power boat racing. They delimit the course and must be passed to a specified side. They are also used in [[underwater orienteering]] competitions.
* [[Emergency wreck buoy|'''Emergency wreck buoys''']] provide a clear and unambiguous means of temporarily marking new wrecks, typically for the first 24–72 hours. They are coloured in an equal number of blue and yellow vertical stripes and fitted with an alternating blue and yellow flashing light. They were implemented following collisions in the Dover Strait in 2002 when vessels struck the new wreck of the {{Ship|MV|Tricolor}}.<ref>{{cite web|url=http://www.trinityhouse.co.uk/lighthouses/buoys/emergency_wreck.html |title=Emergency Wreck Buoys &#124; Navigation Buoys &#124; Trinity House |access-date=2014-05-26 |url-status=dead |archive-url=https://web.archive.org/web/20140702032424/http://www.trinityhouse.co.uk/lighthouses/buoys/emergency_wreck.html |archive-date=2014-07-02 }}</ref>
* '''Ice marking buoys''' mark holes in frozen lakes and rivers so snowmobiles do not drive over the holes.
* '''Large Navigational Buoys''' (LNB, or [[Lanby buoy|'''Lanby buoys''']]) are automatic buoys over 10&nbsp;meters high equipped with a powerful light monitored electronically as a replacement for a [[lightvessel]].<ref>{{Cite web|title=Large Navigational Buoys (LNB)|url=http://www.uscg.mil/history/articles/LNB.asp|publisher=United States Coast Guard|access-date=Jul 6, 2015}}</ref> They may be marked on charts as a "Superbuoy."<ref name=":0">{{Cite book|title=US Chart No. 1|author=National Oceanic and Atmospheric Administration|publisher=NOAA|year=2013|location=Silver Spring|pages=89}}</ref>
* [[Navigational aid#Lateral marker|'''Lateral marker''']] '''buoys'''
* '''[[Safe water mark]]''' or [[Fairway Buoy|'''fairway buoys''']] mark the entrance to a channel or nearby landfall
* [[Sea mark|'''Sea marks''']] aid [[pilotage]] by marking a [[Shipping|maritime]] channel, hazard or administrative area to allow [[boat]]s and [[ship]]s to [[navigation|navigate]] safely. Some are fitted with wave-activated bells or gongs.
* '''Wreck buoys''' mark a wrecked ship to warn other ships to keep away because of unseen hazards.
* [[wiktionary:light buoy|'''Light buoys''']] provide demarcation at night.

=== Marker buoys ===
Buoys are often used to temporarily or permanently mark the positions of underwater objects:
* '''Lobster trap buoys''' are brightly colored buoys marking lobster trap locations so [[lobster fishing|lobster fishers]] can find their lobster traps. Each fisher has a unique colour marking or registration number.  They are allowed to haul only their own traps, and must display their buoy colour or license number on their boat so law enforcement officials know what they should be hauling. The buoys are brightly coloured with highly visible numbers so they can be seen in poor visibility conditions like [[rain]], [[fog]] and [[sea smoke]].<ref>Cobb, John N., [http://www.gutenberg.org/files/17475/17475-h/17475-h.htm#7 "The Lobster Fishery of Maine"], Bulletin of the United States Fish Commission, Vol. 19, Pages 241–265, 1899; from [[Project Gutenberg]]</ref><ref>Taft, Hank; Taft, Jan, [http://www.mainecoastguide.com/ ''A Cruising Guide to the Maine Coast and the Maine Coast Guides for Small Boats''], Peaks Island, Maine : Diamond Pass Publishing, 5th Edition, 2009. Cf. Chapter: [http://www.mainecoastguide.com/sidebars/buoys.html "BUOY, OH BUOY"] {{webarchive|url=https://web.archive.org/web/20081118013143/http://www.mainecoastguide.com/sidebars/buoys.html |date=2008-11-18 }}, and Chapter: [http://www.mainecoastguide.com/intro/fshrmn.html "Fisherman, Lobsterboats, and Working Harbors"] {{webarchive|url=https://web.archive.org/web/20120320212945/http://www.mainecoastguide.com/intro/fshrmn.html |date=2012-03-20 }}</ref>
* '''[[Fishing float]]s''' are a type of lightweight buoys used in [[angling]] to mark the position of the [[fishing bait|bait]]ed [[fish hook|hook]] suspended underneath, and as a [[bite indicator]] to signal the angler any changes in the hook's underwater status.

==== Diving ====
Several types of marker buoys may be used by [[Underwater diving|divers]]:
* [[Decompression buoy|'''Decompression buoys''']] are deployed by submerged [[Scuba diving|SCUBA]] divers to mark their position underwater whilst doing [[decompression stops]]
* [[Diving shot|'''Shot buoys''']] mark dive sites for the boat safety cover of [[scuba diving|scuba divers]] so they can descend to dive sites more easily in conditions of low visibility or [[tide|tidal currents]] and more safely do [[decompression stops]] on their ascents.
* [[Surface marker buoy|'''Surface marker buoys''']] are taken on dives by [[scuba diving|scuba divers]] to mark their positions underwater.<ref name=Davies>{{cite journal |author=Davies, D |title=Diver location devices |journal=Journal of the [[South Pacific Underwater Medicine Society]] |volume=28 |issue=3 |year=1998 |url=http://archive.rubicon-foundation.org/5968 |access-date=2013-04-16 |archive-url=https://web.archive.org/web/20090519022556/http://archive.rubicon-foundation.org/5968 |archive-date=2009-05-19 |url-status=usurped }}</ref>
* '''Dive site demarcation buoys''' indicate that divers are working in the marked area, to warn passing vessels to stay clear.

=== Rescue ===
* [[Lifebuoy|'''Lifebuoys''']] are lifesaving buoys thrown to people in the water to provide [[buoyancy]]. They usually have a connected line allowing them to be pulled in.
*[[Self-locating datum marker buoy|'''Self-locating datum marker buoys''']] (SLDMB) are 70% scale Coastal Ocean Dynamics Experiment (CODE)/Davis-style oceanographic surface drifters with drogue vanes between 30 and 100&nbsp;cm deep,<ref name="METOCEAN">[METOCEAN. (2008). METOCEAN SLDMB: Operating & Maintenance Manual (Version 3.0 ed.) Retrieved from http://www.metocean.com.</ref> designed for deployment from [[U.S. Coast Guard]] vessels or airframes for search and rescue. They have very little surface area above water to minimize [[leeway|the effects]] on them off winds and waves.<ref name="Bang">[Bang, I., Mooers, C. N. K., Haus, B., Turner, C., Lewandowski, M. (2007). Technical Report: Surface Drifter Advection and Dispersion in the Florida Current Between Key West and Jacksonville, Florida. Technical Report.].</ref>
* [[Rescue buoy (submarine)|'''Submarine rescue buoys''']] are released in emergencies and for communication purposes.

=== Research ===
* '''[[Profiling buoy]]s''' are specialized buoys that adjust their buoyancy to sink at a controlled rate to a set depth, for example 2,000 metres while measuring sea temperature and salinity. After a certain period, typically 10 days, they return to the surface, transmit their data via satellite, then sink again.<ref name=Kery1989>{{cite journal |author=Kery, SM |title=Diving in support of buoy engineering: The RTEAM project |journal=In: Lang, MA; Jaap, WC (Ed). Diving for Science…1989. Proceedings of the American Academy of Underwater Sciences Annual Scientific Diving Symposium 28 September – 1 October 1989 Wood Hole Oceanographic Institution, Woods Hole, Massachusetts, USA |year=1989 |url=http://archive.rubicon-foundation.org/10199 |access-date=2013-04-16 |archive-date=2013-06-21 |archive-url=https://web.archive.org/web/20130621195811/http://archive.rubicon-foundation.org/xmlui/handle/123456789/10199 |url-status=usurped }}</ref> See [[Argo (oceanography)]].
* [[Deep-ocean Assessment and Reporting of Tsunamis|'''Tsunami buoys''']] are anchored buoys that can detect sudden changes in undersea water pressure, and are a component of [[tsunami warning systems]] in the [[Pacific Tsunami Warning Center]] and Indian Oceans.
*[[Wave buoy|'''Wave buoys''']] measure the movement of the water surface as a wave train. The data they transmit is analysed to form statistics like [[significant wave height]] and period, and wave direction.
* [[Weather buoy|'''Weather buoys''']] measure weather parameters such as air temperature, barometric pressure, and wind speed and direction. They transmit this data, via satellite radio links such as the purpose-built [[Argos System]] or commercial [[satellite phone]] networks, to meteorological centres for forecasting and climate study. They may be anchored (moored buoys), or allowed to drift (drifting buoys) in the open currents. Their position is calculated by the satellite. They are also referred to as [[Ocean Data Acquisition System]]s, or (ODAS) buoys.<ref>{{Cite web|url=http://www.iala-aism.org/wiki/dictionary/index.php/ODAS_buoy|title=International Dictionary of Marine Aids to Navigation – ODAS buoy|last=IALA|date=2008|access-date=10 December 2016}}</ref> and may be marked on charts as "Superbuoys."<ref name=":0" />

=== Mooring ===
* '''Mooring buoys''' keep one end of a [[Mooring (watercraft)|mooring]] cable or chain on the water's surface so [[ship]]s and boats can tie to them. Many [[marina]]s mark them with numbers and assign them to particular vessels, or rent them to transient vessels.
* '''Tripping buoys''' are used to keep one end of a '{{nautical term|tripping line}}' to be used to break out and lift an anchor on the water's surface so that a stuck [[anchor]] can more easily be freed.

=== Military ===
* '''Marker buoys,''' used in [[naval warfare]] (particularly [[anti-submarine warfare]]) emit light and/or smoke using [[pyrotechnic]] devices to create the [[flare]] and [[smoke]]. Commonly 3 inches (76&nbsp;mm) in diameter and about 20&nbsp;inches (500&nbsp;mm) long, they are activated by contact with seawater and float on the surface. Some extinguish themselves after a specific period, while others are sunk when they are no longer needed.
* [[Sonobuoy|'''Sonobuoys''']] are used by [[anti-submarine warfare]] aircraft to detect [[submarine]]s by [[Sonar|SONAR]]
*'''Target buoys''' simulate targets, such as small boats, in live-fire exercises by naval and coastal forces. They are usually targeted by medium-sized weapons such as [[heavy machine gun]]s, rapid fire cannons (~20&nbsp;mm), [[autocannon]]s (up to 40–57mm) and [[Anti-tank warfare|anti-tank rockets]].

===Specific forms===
* '''DAN buoys''' are used as:
** Large maritime [[navigation]]al aids providing a platform for [[light]] and [[radio]] beacons
** Lifebuoys with flags, used on [[yacht]]s and smaller pleasure craft
** Temporary markers in [[Seine fishing#Danish seine|Danish seine]] fishing to mark net anchor positions
** Temporary markers set by [[danlayer]]s during minesweeping operations to indicate the boundaries of swept paths, swept areas, known hazards, and other locations or reference points
** Temporary markers for [[man overboard|rescue operations]] 
* [[Spar buoy|'''Spar buoys''']] are tall, thin buoys that float upright, e.g. [[R/P FLIP]]

===Other===
[[File:Arrival Polar.jpg|thumb|buoy with [[letter box]] in [[Töre]]<ref>RCC Pilotage Foundation: ''Baltic Sea and Approaches''. Imray, Laurie, Norie and Wilson Ltd, 2019, [https://books.google.com/books?id=ZeqKDwAAQBAJ&pg=PA241 p. 241], ISBN 9781846238925.</ref>]]
*Letter boxes on buoys exist in [[Töre]] (Sweden) and at the [[Steinhuder Meer]] (Germany)<ref>[https://www.steinhude-am-meer.de/f5-edit/?domain=www.steinhude-am-meer.de&show=detail&artikel=20 ''Die Postboje''], www.steinhude-am-meer.de.</ref>

===Fictional===
*Imaginary '''“Mail buoys”''' have been used as a [[Practical joke|prank]] in the US Navy when a new sailor may be given the task of locating one to retrieve non-existent mail.<ref>{{cite web|url=http://www.ussrich.org/news/pranks.html|title=Pranks: Some old, some new|publisher=USS RICH Association|website=USS RICH}}</ref>
*'''Space buoys,''' a feature in some science fiction stories which are stationary objects in [[outer space]] that provide navigation data or warnings.{{citation needed|date=March 2021}}

==Other uses==

*The word "buoyed" can also be used figuratively. For example, a person can buoy up ('lift up') someone's spirits by providing help and empathy.<ref>{{cite OED2|buoy|volume=II|page=661}} verb, sense 3.</ref>
*Buoys are used in some [[wave power]] systems to generate electrical power.<ref>{{Cite web |title=Buoy System Harnesses Wave Energy |url=https://abcnews.go.com/Technology/CuttingEdge/story?id=98434&page=1 |access-date=2023-09-25 |website=ABC News |language=en}}</ref>
*[[George A. Stephen]], founder of [[Weber-Stephen Products Co.]], invented the kettle grill by cutting a metal buoy in half and fashioning a [[dome]] shaped grill to it with a rounded lid.<ref>[http://weber.mediaroom.com/index.php?s=pageA&item=1 George Stephen, Company Founder and Inventor of the Weber Kettle Grill] {{webarchive |url=https://web.archive.org/web/20070623131242/http://weber.mediaroom.com/index.php?s=pageA&item=1 |date=June 23, 2007 }}</ref>

==Gallery==
<gallery>
File:NorderneyBojen.JPG|Several different buoys at a storage depot.
File:BUOY.JPG|A buoy used as turn marker for sailing races.
File:Iron Buoys Great Barrier Island.jpg|Old iron buoys, most likely for mooring.
File:C0660-NN-Volga-Bridge.jpg|Children playing on a buoy in the [[Volga]]
File:Surface Buoys (Recycled).png|Recycled surface buoys
File:Boa spiaggiata.jpg|A buoy beached at [[Sebastian Inlet State Park]].
File:Telephone buoy of HMS Nordkaparen (Nor).JPG|Emergency buoy of the Swedish submarine ''Nordkaparen''
File:Gas buoy stranded on land by hurricane.jpg|Gas buoy stranded on land after [[1915 Galveston Hurricane]], near Texas City, Texas
File:Boya Buoy.jpg|Starboard lateral Buoy ([[Lateral mark]] - Region B - [[International Association of Marine Aids to Navigation and Lighthouse Authorities|IALA]] ) as Channel Marker Buoy at "Río de la Plata" river, [[Buenos Aires]], Argentina
File:Envirtech Tsunami Buoy MKIII.jpg|Tsunami buoy before deployment in Andaman Sea
File:Lobster buoys.jpg|Lobster buoys hanging on a tree, Sprucehead Island, Maine, United States
File:Buoyyard.jpg|Buoys in dry storage, Homer, Alaska
File:SVP-B.jpg|Drifting Buoy fitted with a Barometer
File:Ship1258 - Flickr - NOAA Photo Library.jpg|Buoy undergoing repair
File:Ring buoy with light.jpg|Ring life buoy with a light on a cruise ship
File:Whitby Warning Buoy.jpg|North cardinal buoy off the coast of [[Whitby]], [[North Yorkshire]]
File:Null Island 2017.jpg|The weather buoy moored at the coordinates of [[Null Island]], located at 0°N 0°E
File:Mr-2s.jpg|Ice-resistant buoys MR-2S and N-2 at a playground in Tallinn, Estonia
</gallery>

== See also ==
{{Portal|Transport}}
{{div col}}
* {{annotated link|Bowditch's American Practical Navigator|''Bowditch's American Practical Navigator''}}
* {{annotated link|Buoy anti-tank obstacle}}
* {{annotated link|Buoyancy}}
* {{annotated link|Day beacon}}
* {{annotated link|GPS buoy}}
* {{annotated link|International Arctic Buoy Program}}
* {{annotated link|Lateral mark}}
* {{annotated link|Lighthouse}}
* {{annotated link|Lightvessel}}
* {{annotated link|List of lights}}
* {{annotated link|PowerBuoy}}
* {{annotated link|United States Coast Pilot|''United States Coast Pilot''}}
{{div col end}}

==References==
{{Reflist|30em}}

==External links==
{{Wiktionary}}
{{EB1911 poster|Buoy}}
{{Commons category|Buoys}}
*[https://web.archive.org/web/20101010154115/http://www.jcommops.org/dbcp/network/maps.html Global Buoy Network Maps]
*[http://www.cgate.co.il/eng/Seamanship/tafrit.htm Lighthouses and Buoys] {{Webarchive|url=https://web.archive.org/web/20130124215440/http://cgate.co.il/eng/Seamanship/tafrit.htm |date=2013-01-24 }}
*[https://web.archive.org/web/20090907100035/http://buoyalerts.com/ North American Buoy Map]

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{{Seamanship}}

[[Category:Nautical terminology]]
[[Category:Marine navigation]]
[[Category:Buoyage| ]]
[[Category:Maritime safety]]