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aground—the force of impact will push the foil back into the centreboard trunk, rather than breaking it, as might happen if the board were locked in place. The mass of a ballasted foil means that a system of pulleys may be required to allow the sailor to lift the foil, and a method of latching the board in the upward position is needed. A centreboard differs from a ballast keel in that centreboards do not contribute to the stability of the vessel; their purpose is to provide lateral resistance. In small sailing dinghies it is rare to find a ballasted centreboard.
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248:. A long narrow centreboard produces less drag than a short, wide one for a given amount of lift, resulting in a faster boat that can point closer into the wind. A fore and aft, pivoting centreboard can also be used to move the centre of lateral resistance aft to match a change in sail plan, such as furling or dropping the jib. A retracting centreboard is more complex than a fixed
252:, and most take up space inside the hull of the boat that could otherwise be used for passenger accommodation. Other types feature a casing under the boat, which does not take up space but instead has the problem of increased drag. For this reason, it is not uncommon to find boats with a combination of shallow keel and centreboard (e.g.
156:(US). The retractability allows the centreboard to be raised to operate in shallow waters, to move the centre of lateral resistance (offsetting changes to the sailplan that move the centre of effort aft), to reduce drag when the full area of the centreboard is not needed, or when removing the boat from the water, as when
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On larger sailing vessels, a similar design is sometimes incorporated to facilitate better navigation in shallow water than a fixed keel would allow. In these situations the appendage is generally referred to as a "lifting keel" (which is usually pivoted but occasionally retracted like a daggerboard)
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is never closer than 45 degrees to the apparent wind. Since most sailboats are symmetric along their axis of motion, when sailing upright, the lateral force can come from either side, which means that centreboards must use symmetric foil shapes so they will operate with equal efficiency on either
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and called "lifting keels" because like keels they are centred under the hull, although unlike keels, they are retractable. Ballasted centreboards are generally not locked in place when lowered; the mass of the ballast keeps them down. This also provides a measure of safety should the boat run
256:). The keel provides the housing for the centreboard, moving it out of the hull, but adds only a small amount of draft to the boat. The centreboard can then be lowered in deeper waters to increase the amount of lift.
196:(c. 1740 – 6 February 1823) was an officer of the British Royal Navy and is credited with the invention of the centerboard. Schank, however, gave credit for the idea to British Brigadier General Earl Percy.
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In such installations on offshore vessels, the keel should ideally be lockable in any position, so that it does not fall back into the keel well if the vessel is
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The centerboard, daggerboard or bilgeboard can be used as a recovery platform upon which to stand, providing increased
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A centreboard (often called a lifting foil in a modern racing dinghy) is used to provide
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is usually provided in the keel, keeping the centreboard lighter and easier to handle.
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The efficiency of a centreboard improves with increasing
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is similar but slides vertically rather than pivoting.
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When the craft is moving, the centreboard acts as a
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371:"The Equipment Rules of Sailing for 2021-2024"
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109:Learn how and when to remove this message
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208:to counter the lateral force from the
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385:, Section E.1.2 Hull Appendage Types
349:"What's the deal with Centerboards?"
263:Centreboards are often ballasted in
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351:. Sailing Soulianis. 21 March 2020
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455:Apparent wind indicator
136:(US) is a retractable
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272:or a "swing keel".
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58:"Centreboard"
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32:This article
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530:Companionway
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424:sailing ship
378:. Retrieved
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240:How it works
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41:Please help
36:verification
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650:Quarterdeck
540:Daggerboard
535:Crow's nest
515:Centreboard
485:Bow or prow
435:Aftercastle
422:Parts of a
304:Daggerboard
194:John Schank
166:daggerboard
162:centerplate
134:centerboard
130:centreboard
740:Categories
620:Orlop deck
555:Forecastle
550:Figurehead
480:Boom brake
470:Bilgeboard
380:2022-10-14
335:References
299:Bilgeboard
177:bilgeboard
158:trailering
99:March 2022
69:newspapers
720:Whipstaff
690:Sternpost
680:Starboard
630:Poop deck
625:Outrigger
440:Afterdeck
355:March 10,
265:keelboats
700:Taffrail
640:Porthole
610:Leeboard
585:Jackline
490:Bowsprit
460:Beakhead
324:Leeboard
293:See also
277:inverted
254:Randmeer
222:leverage
152:(UK) or
146:sailboat
715:Transom
590:Jibboom
570:Gunwale
565:Gangway
525:Cockpit
505:Cathead
500:Capstan
284:lifting
258:Ballast
230:capsize
200:Purpose
188:History
183:General
83:scholar
705:Tiller
695:Strake
660:Rudder
605:Kelson
520:Chains
445:Anchor
309:Dinghy
234:turtle
226:dinghy
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725:Winch
560:Frame
495:Cable
475:Bitts
465:Bilge
374:(PDF)
210:sails
175:is a
144:of a
90:JSTOR
76:books
675:Stem
670:Skeg
635:Port
615:Mast
595:Keel
580:Hull
575:Head
545:Deck
357:2022
329:Skeg
287:foil
250:keel
214:sail
206:lift
192:Lt.
173:scow
142:hull
62:news
710:Top
655:Rib
232:or
132:or
45:by
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