Windward and leeward

Windward (/ˈwɪndwərd, ˈwɪnərd/) is the direction upwind from the point of reference, alternatively the direction from which the wind is coming. Leeward (/ˈliːwərd, ˈljuːərd/) is the direction downwind (or downward) from the point of reference. The leeward region of mountains generally remains dry as compared to the windward. The side of a ship that is towards the leeward is its lee side. If the vessel is heeling under the pressure of the wind, this will be the "lower side". During the age of sail, the term weather was used as a synonym for windward in some contexts, as in the weather gage.

Upwind downwind example
Example image showing definitions of windward (upwind) and leeward (downwind)

Nautical and naval

Windward and leeward directions are important factors (points of sail) to consider when sailing a sailing ship. Other terms with broadly the same meaning are widely used, particularly upwind and downwind.[1]

The windward vessel is normally the more maneuverable vessel. For this reason, rule 12 of the International Regulations for Preventing Collisions at Sea, applying to sailing vessels, stipulates that where two are sailing in similar directions in relation to the wind, the windward vessel gives way to the leeward vessel.[2]

Naval warfare

In warfare, a square rigged warship would often try to enter battle from the windward direction (or "hold the weather gage"), thus gaining an important tactical advantage over the opposing warship – the warship to windward could choose when to engage and when to withdraw. The opposing warship to leeward could often do little but comply without exposing itself unduly.[3]

This was particularly important once artillery was introduced to naval warfare. Ships heel away from the wind, so the leeward vessel was exposing more of her side to shot.[4]

Meteorological significance

Leeward and windward refer respectively to what a game stalker would call downwind and upwind.[5] The terms are used by seamen in relation to their ships but also in reference to islands in an archipelago and to the different sides of a single island. In the latter case, the windward side is that side of an island subject to the prevailing wind, and is thus the wetter side (see orographic precipitation). The leeward side is the side protected by the elevation of the island from the prevailing wind, and is typically the drier side of an island. Thus, leeward or windward siting is an important weather and climate factor on oceanic islands.[6]

In the case of an archipelago, windward islands are upwind and leeward islands are the downwind ones.

The terms upwind and downwind

In these contexts the terms windward and layward are not used.

  • Hunting: In hunting, the animal that is downwind has an advantage. It can smell the upwind animal, but the reverse is not true. The downwind animal has the advantage of surprise when hunting the upwind animal.
  • Architecture and urban planning: Part of a house, or a community, is located upwind of something downwind that is malodorous — an outhouse, a garbage dump, a feedlot, a factory or meatpacker. It is sometimes the case that part of a house or a community, or sometimes the entire house or community, will be downwind of some pleasant odor. These odors are either plant-based — flowers, fruit or flowering trees, forests —, or moving water — rivers, waves, rain.

See also


  1. ^ Patrick M. Royce (1 April 1993). Royce's Sailing Illustrated Course: Provides Lectures That Can Be Read Word for Word. ProStar Publications. pp. 11–. ISBN 978-0-911284-01-0.
  2. ^ Navigators International Rules of the Road' 1998 Ed. Rex Bookstore, Inc. pp. 73–. ISBN 978-971-23-2239-6. Handling of the leeward vessel may be severely affected if she passes into the lee of the windward vessel. Handling of the windward vessel is free of such complication.
  3. ^ David Childs (30 April 2014). The Warship Mary Rose: The Life and Times of King Henry VII's Flagship. Seaforth Publishing. pp. 127–. ISBN 978-1-4738-5285-3.
  4. ^ Sam Willis (2008). Fighting at Sea in the Eighteenth Century: The Art of Sailing Warfare. Boydell Press. pp. 152–. ISBN 978-1-84383-367-3. Specifically, more of the critical strip "twixt wind and water". In extreme cases even part of the bottom might be exposed.
  5. ^ E. B. Michell (22 December 2015). The Art and Practice of Hawking. Read Books Limited. pp. 250–. ISBN 978-1-4733-6546-9.
  6. ^ Michael Pidwirny (5 September 2016). Glossary of Terms for Physical Geography. Our Planet Earth Publishing. pp. 286–. ISBN 978-0-9877029-0-6.
Abraham Josias Cloëté

General Sir Abraham Josias Cloëté KCB (7 August 1794 – 26 October 1886) was an Afrikaner senior officer in the British Army.

He was born in Cape Town, the son of Pieter Lourens Cloëté, member of the council of the Cape of Good Hope, and Catharina Maria Van Zeeman. On 29 January 1809, he joined the British Army as a cornet in the 16th Hussars.

He transferred to the 15th Hussars on their return from Corunna, serving with them during the Burdett riots of 1810 and the Luddite disturbances in the Midlands and Lancashire of the following years. In 1813 he exchanged as a captain to the 21st Light Dragoons at the Cape, where he acted as aide-de-camp to the newly appointed governor, Lord Charles Somerset. Whilst stationed there he commanded a military detachment, made up of volunteers from regiments at the Cape, which occupied the remote desert island of Tristan da Cunha soon after the arrival of the Emperor Napoleon on Saint Helena and also fought a duel with the transexual army surgeon James Barry. He rose through the ranks to lieutenant (17 May 1810) and captain (5 November 1812).

In 1817, he went with his regiment to India, serving with a squadron employed as a field force in Cuttack, on the frontiers of Orissa and Bihar, during the Third Anglo-Maratha War of 1817–19. The 21st Dragoons (except a detachment on Saint Helena) were disbanded in England in May 1819 and Cloëté was placed on half-pay.

In 1820, he was occupied as deputy-assistant quartermaster-general, in superintending the landing and settling of a large body of government immigrants, known as 1820 Settlers, on the eastern frontier of the Cape Colony. In 1822 he was sent home with important despatches, made brevet major on 21 November 1822, and appointed town-major of Cape Town, a post he held until 1840. He was promoted lieutenant-colonel on 10 January 1837 and given the honour of KH. In 1840 he was appointed deputy quartermaster-general at the Cape, and retained the post until 1854, by which time he had been promoted Colonel (11 November 1851).

In 1842, he was sent with reinforcements from Cape Town to relieve a small force under Captain Smith of the 27th (Inniskilling) Regiment of Foot, which was besieged by insurgent Boers near Port Natal (now Durban), when his firm action not only prevented battle, but prepared the way for permanent settlement of the subsequent colony of Natal. He was quartermaster-general in the Xhosa Wars of 1846, was mentioned in despatches, and in 1848 made C.B. He was chief of the staff with the army in the field in the Kaffir war of 1851–3, including the operations in the Basuto country, and at the Battle of Berea, where he commanded a division. He was knighted for his services in 1854.

Promoted major-general on the staff (19 January 1856), he commanded the troops in the Windward and Leeward Islands from 1855 to 1861. He was given the colonelcy for life of the 19th Foot in 1861 and made KCB in 1862. He became Lieutenant-general on 12 February 1863 and full General on 25 October 1871.He was placed on the retired list in 1877 and died at his London home in 1886. He had married in Barbados, on 8 May 1857, Anne Woollcombe Louis, the granddaughter of the late Rear-admiral Sir Thomas Louis, baronet, with whom he had a son and a daughter.

Andrew Halliday (physician)

Sir Andrew Halliday, KH (also spelt Hallidie; 17 March 1782 in Copewood, parish of Dryfesdale, Dumfries – 7 September 1839 in Dumfries) was a Scottish physician, reformer, and writer.

Andrew Halliday (physician) bibliography

This is a list of works published by Sir Andrew Halliday, K.B.E., M.D.

Antilles Crossing

Antilles Crossing is an underwater 20 gigabit per second (Gbit/s) fiber optics ring network connecting several nations and overseas territories of the Caribbean Sea.

It was built by TeleBarbados, and is one of the newer important network connections to the Internet for Caribbean countries in the Windward and Leeward Islands. The company is a joint venture between Leucadia National Corporation and Barbados Light & Power Holdings Limited. It currently extends from Needham's Point, Saint Michael, Barbados to Saint Croix in the U.S. Virgin Islands where it interconnects with Global Crossing's worldwide telecommunications network.

The network is being built in 4 phases.

Phase I (The red phase) links Barbados, to the island of Saint Croix in the United States Virgin Islands.

Phase II (The grey phase) will see the linking of Barbados firstly to Tobago and then onward to Trinidad further south.

Phase III (The green phase) will see the link from Trinidad traveling Northward to Grenada, Saint Vincent, and Saint Lucia.

Phase IV (The blue phase) will see a link extended from Saint Lucia Northward to Martinique, Guadeloupe, Saint Kitts and Saint Croix in United States Virgin Islands

Attorney-General of Belize

The Attorney-General of Belize is a cabinet-level official who acts as the principal legal adviser to the government of Belize.

British Windward Islands

The British Windward Islands was a British colony in the Windward Islands of the West Indies, existing between 1833 and 1960 and consisting of the islands of Grenada, St Lucia, Saint Vincent, the Grenadines, Barbados (the seat of the governor until 1885, when it returned to its former status of a completely separate colony), Tobago (until 1889, when it was joined to Trinidad), and (from 1940) Dominica, previously included in the British Leeward Islands.

The colony was known as the Federal Colony of the Windward Islands from 1871 to June 1956, and then as the Territory of the Windward Islands until its dissolution in 1960.

Chief Justice of Grenada

The Chief Justice of Grenada is the head of the Supreme Court of Grenada which consists of the High Court with three justices and a two-tier Court of Appeal.The original High Court of Grenada was replaced by the Windward and Leeward Islands Supreme Court and the Windward and Leeward Islands Court of Appeal in 1939; both of the latter were replaced in 1967 by the Eastern Caribbean Supreme Court which performs both functions. The Eastern Caribbean Supreme Court, known in Grenada as the Supreme Court of Grenada and the West Indies Associated States, is headquartered in St Lucia, and is now the superior court of record for Grenada and the other Caribbean states which comprise the Organisation of Eastern Caribbean States.

Chief Justice of St Lucia

The Chief Justice of St Lucia was the head of the Supreme Court of St Lucia, an island member of the Windward Islands in the West Indies.

The court was replaced by the Windward and Leeward Islands Supreme Court and the Windward and Leeward Islands Court of Appeal in 1939; both in turn were replaced in 1967 by the Eastern Caribbean Supreme Court which performs both functions.

Chief Justice of St Vincent

The Chief Justice of St Vincent was the head of the Supreme Court of Saint Vincent in Saint Vincent, an island member of the Windward Islands in the West Indies.

The court was replaced by the Windward and Leeward Islands Supreme Court and the Windward and Leeward Islands Court of Appeal in 1939; both in turn were replaced in 1967 by the Eastern Caribbean Supreme Court which performs both functions.

Chief Justice of the Leeward Islands

The Chief Justice of the Leeward Islands headed the Supreme Court of the Leeward Islands.

The British Leeward Islands was a British colony existing between 1833 and 1960, and consisted of Antigua, Barbuda, the British Virgin Islands, Montserrat, Saint Kitts, Nevis, Anguilla and Dominica (to 1940). Prior to 1871, when the Supreme Court was established, the individual islands had their own courts.

In 1939 the Windward and Leeward Islands Supreme Court and the Windward and Leeward Islands Court of Appeal were established, which was replaced in 1967 by the Eastern Caribbean Supreme Court which provides both functions.


A crosswind is any wind that has a perpendicular component to the line or direction of travel. This affects the aerodynamics of many forms of transport. Moving non-parallel to the wind's direction creates a crosswind component on the object and thus increasing the apparent wind on the object; such use of cross wind travel is used to advantage by sailing craft, kiteboarding craft, power kiting, etc. On the other side, crosswind moves the path of vehicles sideways and can be a hazard.

Grayson Shillingford

Grayson Cleophas Shillingford (born 25 September 1944, died 23 December 2009) was a West Indian cricketer who played in seven Tests from 1969 to 1972. His cousin Irvine Shillingford, also played Test cricket for the West Indies.

Grayson Shillingford was a right-arm fast bowler who played for Windward Islands from 1967-68 to 1978-79. He toured England with the West Indies team in 1969 and 1973. His best first-class figures were 6 for 49 for the Combined Windward and Leeward Islands team against Trinidad in 1971-72.

Hymenocallis caribaea

Hymenocallis caribaea is a plant in the Amaryllidaceae with the common names "Caribbean spider-lily" or "variegated spider-lily." It is native to the islands of the Caribbean and to northern South America. It is regarded as native to Puerto Rico, Jamaica, Hispaniola, Cuba, the Virgin Islands, and the Windward and Leeward Islands, and the Venezuelan Antilles. It is also commonly cultivated as an ornamental in many other tropical and subtropical regions and reportedly naturalized in Sri Lanka, New South Wales, Bermuda, French Guinea, Suriname, and Guyana.

List of palms native to the Caribbean

Palms are symbolically important in the Caribbean, appearing on the coats of arms of several Caribbean nations and on the flag of the West Indies cricket team. In 2004, Carlo Morici reported that there are about 191 genera and 2339 species of Arecaceae, the palm family. Their distribution is biased toward islands - 36% of genera and 52% of species are found only on islands, while 32% of genera and 6% of species are found only on continents. Sixty-two percent of monotypic genera are found only on islands.Phytogeographically, the Caribbean region is often considered to include the coastal plains of the United States (including south Florida), Mexico (especially the Yucatan), Belize, Colombia and Venezuela. Most species either have a wide distribution which includes part of the Caribbean, or are endemic to the Greater Antilles. Of the islands in the Caribbean, Cuba has the most species of palm, followed by Hispaniola. The Windward and Leeward Islands have the fewest. The palm flora of Trinidad and Tobago consists primarily of species with a South American distribution. Three genera of palm are endemic to the Greater Antilles: Calyptronoma, Hemithrinax and Zombia. Although nearly ubiquitous in the region, the coconut (Cocos nucifera) is not native to the Caribbean. The Caribbean species in the genus Copernicia are all Greater Antillean endemics; two species are restricted to Hispaniola, while the others are restricted to Cuba.

Marcus Beresford (British Army officer, born 1764)

Brigadier-General Marcus Beresford (1 June 1764 – 6 January 1803) was an Irish soldier and Member of Parliament.

He was a son of the Archbishop of Tuam, William Beresford, by his wife Elizabeth, sister of John FitzGibbon, 1st Earl of Clare.Beresford began his military career when he was commissioned as an ensign into the 9th Regiment of Foot on 26 October 1786. He was promoted to lieutenant on 30 June 1787 and then to captain in the 27th Regiment of Foot, later commanding an Independent Company.

On 31 October 1793 he was promoted to first major in the 102nd Regiment of Foot (Trench's) and on 26 November 1794 to lieutenant-colonel in the 135th Regiment of Foot (Sir Vere Hunt's). He was appointed Lieutenant-General of the Irish Ordnance in 1800 and promoted full colonel on 1 January 1801.He represented St Canice in the Irish House of Commons from 1790 to 1794 and Swords from 1798 until the Act of Union 1800. On 22 June 1802, he was breveted to the local rank of brigadier-general in the Windward and Leeward Islands.The West Indies garrisons were infamous for mortality through tropical diseases, such as malaria and yellow fever. Accordingly, Beresford made out a will on 23 November 1802 in Barbados. This proved to be a wise precaution, as he died there on 6 January. He died unmarried, predeceasing his father, who was created Baron Decies in 1812 and succeeded by Marcus's younger brother John in 1819.

Piton (beer)

Piton is a Pilsner beer brand from the island of Saint Lucia, brewed by Windward & Leeward Brewing Limited, which is owned by Heineken. The beer was named for the Gros Piton and Petit Piton mountains on the island. It was first brewed on October 7, 1992.

Quietrevolution wind turbine

The Quietrevolution (often stylized with lower-case "q": quietrevolution) is a brand of vertical-axis wind turbine. The helical design is most similar to the Gorlov helical turbine. Both are an evolution of the Darrieus wind turbine. It has won several awards including the "Sustainable Innovation Award" in 2006.

The turbine consists of three vertical airfoil blades, each having a helical twist of 120 degrees. This feature spreads the torque evenly over the entire revolution, thus preventing the destructive pulsations of the straight-bladed giromill (Darrieus turbine). The wind pushes each blade around on both the windward and leeward sides of the turbine.

The qr5 turbine, rated for 6 kW, measures 3.0m in diameter by 5m high.

Poor performance of a QR5 installed at Welsh government offices in Aberystwyth has been blamed on poor siting. The turbine's overall cost was given as £48,000 and in 2012 it generated an average of 33 kWh per month, a value of £5.28 per month.

Quiet Revolution Limited entered liquidation in April 2014. VWT Power Limited (trading as Quiet Revolution) acquired the IP and assets later that year to support the fleet of legacy Qr5 turbines and with the intention of developing a new generation of products.

It became apparent quite early on that many of the early iterations of their Qr5 design had been superseded by huge step changes in their knowledge and progression of the original design. Many of the flaws of the early design were being eradicated by the later iterations however there some fundamental inherent design faults which would take a complete halt and re think. This had been started by QR Limited before going into administration and the basis of the new Qr6 was born however since then this new design has undergone significant design modifications resulting in the new Qr6 being launched today. The blades have a 60% greater swept area, are stiffer and the trailing edge is more precise, reducing drag. The rotating mass of the turbine is now almost completely manufactured from composite materials significantly improving the power to weight ratio. Furthermore the control equipment is more intelligent, accurate and efficient, resulting in less down time caused by noise on the line and vibration issues being misinterpreted. The new software and algorithms have dramatically changed the turbine, enabling an impressive increase in energy generation and reliability.


A tepukei (from Te Puke, meaning an ocean-going canoe) is a very old Melanesian and Polynesian boat type, produced primarily by the Polynesian-speaking inhabitants of Taumako (Duff Islands). It was first reported in print by Spanish explorer Álvaro de Mendaña in 1595, on his visit to the Santa Cruz Islands.

A tepukei looks like an outrigger canoe with a crab claw sail, and is in fact a very sophisticated ocean-going sailing ship, belonging to the proa (two hulls of different size) type. Its main differences from other proas are:

The main hull (vaka) has an almost circular section whose submerged profile remains constant despite heeling, and has a minimum of wet surface when heavily loaded.

The vaka's top is very close to the flotation line, so it is closed with planks and the accommodations for the crew are on an elevated platform over the akas (the beams connecting the main hull and the smaller, windward hull).In common with a typical proa, it uses a crab claw sail, one of the most efficient sail types known.

W. C. O'Ferrall, an Anglican missionary to Melanesia between 1897 and 1904, described the tepukei as a "sailing canoe". He described it as consisting of a dugout log equipped with a deck upon which a small hut was built, powered by a "lofty and strikingly shaped sail", and steered with a long paddle. He reported that men from Santa Cruz used the boat to travel as far away as the Solomon Islands.The Maunga Nefe, which may be the only surviving original tepukei, is in the Ethnological Museum of Berlin. It was brought by Dr. Gerd Koch from the Santa Cruz Islands in 1967.In recent years, tepukeis have been experiencing a renaissance. The Vaka Taumako Project has revived the traditional construction of these boats, and some are even being built in San Francisco.

Turby wind turbine

The Turby is a brand of vertical-axis Darrieus wind turbine. The three vertical aerofoil blades have a helical twist of 60 degrees, similar to Gorlov's water turbines .

The turbine consists of three vertical symmetrical airfoil blades, each having a helical twist. The helical feature spreads the torque evenly over the entire revolution, thus preventing the destructive pulsations of the straight-bladed giromill (Darrieus turbine). The wind pushes each blade around on both the windward and leeward sides of the turbine. As with a Darrieus turbine, theoretically, there is no torque on a stationary turbine, due to symmetry of the turbine and of the blades. Starting is achieved by operating the generator as a motor. Torque is caused by a change in the apparent wind direction relative to the moving blades.

Another advantage of the helical twist is that the blades generate torque well from upward-slanting airflow. This is negligible in open country, but tall buildings and cliff faces generate a bow wave which directs airflow up and over them. Turbines mounted on high building rooftops or clifftops are exposed to significantly slanting flow, and the Turby can extract more useful energy from it than a propeller-type turbine can because horizontal axis (HAWT) types cannot change their pitch to face the wind directly.

The turbine measures 2.0 m (6'7") in diameter by 2.9 m (9'6") high (including generator), and weighs 136 kg (300 lb). It is specified to generate power in winds of between 4 m/s (9 mph, 7.8kts) and 14 m/s (31 mph, 27.2kts), and can survive winds of 55 m/s (123 mph, 107kts). The rated power at 14 m/s is 2.5 kW (3.35 hp). The AC output from the synchronous generator is rectified to DC, then inverted to AC at 230 V 50 Hz.

Core International developed the turbine in the Netherlands with research input from the Delft University of Technology.


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