View source for Reefing

{{short description|Reducing the area of a sail}}
[[File:Reefed Sail (PSF).png|thumb|Reefed Sail]]
[[File:Gaff-rigged-sail-nr.svg|thumb|Gaff sail, showing reefing cringles (13), reefing points (20) and reefing lines (21)]]
{{wikt|reefing}}

'''Reefing''' reduces the area of a [[sail]], usually by folding or rolling one edge of the [[canvas]] in on itself and attaching the unused portion to a [[Spar (sailing)|spar]] or a {{linktext|stay}}, as the primary measure to preserve a [[sailing vessel]]'s stability in strong winds. Restoring full sail area is termed ''shaking out'' a {{linktext|reef}}.<ref name="bingham">{{cite web |author= Bingham, Bruce |date= 20 May 2015 |title= How to Reef the Main |url= http://www.cruisingworld.com/seamanship-101-reefing-main |access-date= 3 April 2016 |work=Cruising World}}</ref> 

Whereas [[Fore-and-aft rig|fore-and-aft rigged]] vessels store the unused portion of the sail on a [[boom (sailing)|boom]] (below the sail), [[square rig|square-rigged]] vessels stow the unused portion on a spar above the sail. Reefing may occur by rolling the sail around its [[Sail components|luff]] or [[Foot (sailing)|foot]], either on a rotating stay or within a spar.

== Fore-and-aft rigs ==
[[Image:Bavaria 36 Kroatien 2006.jpg|right|thumb|A [[Genoa (sail)|genoa]] jib completely furled around the forestay, and mainsail partially furled within the mast (forming a reef) on a [[Bavaria Yachtbau|Bavaria 36]] sloop]]
Sails may have built-in alternative attachment points that allow their area to be reduced. In a mainsail, reefing [[cringle]]s may be installed in the sail; a cruising boat will typically have two to three pairs. These are pulled down to the boom to form a new tack and clew, reducing the sail's area. The first pair closest to the boom is called a single reef, the next pair is called a double reef, and so on. A sail usually has eyelets at the same level as the reefing cringles. These are used with reefing points (short lengths of small rope either permanently or temporarily fed through the sail) to secure the excess fabric of the sail after reefing; the points are passed under the foot of the sail or round the boom and tied with a reef knot . Alternatively, a reefing line can be fed through all the eyelets and round the foot of the sail. This keeps the wind out of the unused part of the sails and may improve visibility.<ref name="jobson">{{cite book | title=Sailing Fundamentals | publisher=Simon & Schuster | author=Jobson, Gary | year=1998 | isbn=0684849941 | url-access=registration | url=https://archive.org/details/isbn_9780743273084 }}</ref><ref name="bingham"/><ref>{{cite web |title=How to reef - expert advice from PBO Sail Clinic |url=https://www.pbo.co.uk/seamanship/pbo-sail-clinic-how-to-reef-25713#:~:text=Reefing%20the%20mainsail,right%20place%20and%20properly%20tensioned. |website=Practical Boat Owner |access-date=19 February 2025 |date=26 December 2015}}</ref>

=== Slab ===
Slab or ''jiffy'' reefing allows for the quick establishment of a new tack and clew, while the halyard is partially lowered and then raised. One or two reefing lines passing through the sail's luff and leach reef [[Cringle|cringles]] create a new tack and clew for the sail by pulling them tight to the boom. These can be led back to the cockpit to allow crew members to reef without going on deck in heavy weather. Intermediate reef cringles need not be used.<ref name=":0" /><ref>{{Cite book |last=Caswell |first=Chris |url=https://books.google.com/books?id=GEMz61vsAv4C&dq=jiffy+slab+reefing&pg=PA90 |title=Chartering a Boat: Sail and Power |date=2001 |publisher=Sheridan House, Inc. |isbn=978-1-57409-111-3 |pages=90 |language=en}}</ref>

=== Roller ===
Roller reefing rolls or wraps the sail around a wire, foil, or [[spar (sailing)|spar]] to reduce its exposure to the wind. In mainsail furling systems the sail is either wrapped around the [[Boom (sailing)|boom]] by a mechanism in the [[Gooseneck (sailing)|gooseneck]] or hardware inside the boom winds it around a rotating foil. Furling systems controlled with lines led to the cockpit allow reefing without crew having to go on deck in heavy weather. Roller reefing also allows more variable sail area than conventional or jiffy reefing. Countering these advantages are the furled sail possibly not having an optimal shape and sail repair or replacement being more difficult. In-mast roller-furling mainsails are not conducive to good sail shape.<ref name=":0">{{Cite book |last1=Howard |first1=James D. |url=https://books.google.com/books?id=NB4uFQuUlnEC&dq=jiffy+slab+reefing&pg=PA170 |title=Handbook of Offshore Cruising: The Dream and Reality of Modern Ocean Cruising |last2=Howard |first2=Jim |last3=Doane |first3=Charles J. |date=2000 |publisher=Sheridan House, Inc. |isbn=978-1-57409-093-2 |pages=170 |language=en}}</ref>

== Square rigs ==
[[File:Chesapeake.jpg|thumb|Square-rigged, 18th-century [[frigate]], showing reef bands across the sails.]]
Square-rigged sails hang from a spar, called a [[Yard (sailing)|yard]]. When reefed, the sail is pulled upwards and affixed to the yard at one of the reef bands that runs horizontally across the sail. Each reef band is a canvas-reinforced strip, which contains [[Cringle|cringles]]—eyes through which the reefing points (short pieces of rope) pass that attach the sail to the yard. A sail may have several reef bands to shorten sail to different degrees.<ref>{{Cite book |last=Mayne |first=Richard |url=https://books.google.com/books?id=BGYPEAAAQBAJ&dq=reefing+square+rigger&pg=PA233 |title=The Language of Sailing |date=2018-10-24 |publisher=Routledge |isbn=978-1-135-96558-7 |pages=233 |language=en}}</ref>
==History==
[[File:Dublin (seal, 1297).png|thumb|Reef points shown on the Dublin City seal, 1297]]The earliest known depiction of reef points is on the Dublin City Seal of 1297.<ref name="Brindley 1913">{{cite journal |last1=Brindley |first1=H. H. |title=Mediæval Ships: No. VII |journal=The Mariner's Mirror |date=1 January 1913 |volume=3 |issue=1 |pages=14–17 |doi=10.1080/00253359.1913.10654659 |url=https://doi.org/10.1080/00253359.1913.10654659 |access-date=3 June 2025}}</ref> The earliest surviving example of reef points is on the sail for a [[ship's boat]] found on the wreck of [[Vasa (ship)|''Vasa'']], which sank in 1628.<ref name="Bartoš 2023">{{cite book |last1=Bartoš |first1=Louis|last2=Bengtsson |first2=Sven |last3=Svensson|first3=Sam|last4=Hocker|first4=Fred|editor1-last=Hocker |editor1-first=Fred |title=Vasa. II Part 1: Rigging and sailing a Swedish warship of 1628 The material remains and archaeological context |date=2023 |publisher=Vasamuseet ; Nordic Academic Press |location=Stockholm : Lund |isbn=978-91-88909-11-4 |chapter=7: Sails}}</ref>{{rp|326}} ''Vasa{{'}}s'' own sails included ones which had {{nautical term|bonnet}}s. These are extra pieces that fasten to the bottom of a sail to increase its area. These were attached for lighter winds and removed in higher winds. This was the common method of adjusting sail area to match wind strength during the Medieval period. Other evidence of use of bonnets has been found on the ''[[Mary Rose]]''.{{r|Bartoš 2023}}

==See also==
*[[Brail]]
*[[Glossary of nautical terms (M-Z)]]

==References==
{{Reflist}}
{{cite book | title = The Annapolis Book of Seamanship | first =  John | last =  Rousemaniere | date = 7 January 2014 | isbn = 978-1451650198 }}

{{Sailing manoeuvres}}

[[Category:Sailing manoeuvres]]