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

Windward is the direction from which the wind is blowing at the time in question. The side of a ship which is towards the windward is the weather side. If the vessel is heeling under the pressure of the wind, this will be the "higher side"

Leeward is the direction downwind from the point of reference. The side of the ship towards the leeward is its lee side. If the vessel is heeling under the pressure of the wind, this will be the "lower side".

In general, the nautical pronunciation is ['lju:əd, 'lu:əd] (also monosyllabic [lɪʊəd, lʊəd])^[1] and ['wɪndəd] ([-əɹd] in American English) but nowadays they are rather old-fashioned and ['li:wəd] and ['wɪndwəd] ([-əɹd] in American English) are more common. In any case, the pronunciation for the Lesser Antilles (Leeward and Windward Islands and the Leeward Antilles) is always the second.^[2]

The terms "leeward" and "windward" refer respectively to what a game stalker would call downwind and upwind. 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.

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

Main article: Sailing

Windward and leeward directions are important factors to consider when sailing a sailing ship - see points of sail. Other terms with broadly the same meaning are widely used, particularly "upwind" and "downwind", and many variations using the metaphor of height ("come up", "drop down", "we're pointing higher than them" "head below that mark", and so on).

The windward vessel is normally the more maneouverable vessel. For this reason, rule 12 of the International Regulations for Preventing Collisions at Sea stipulate that the leeward vessel has right of way over the windward vessel. Similarly, a square rigged warship would often try to enter battle from the windward direction (or "hold the weather gauge"), 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. This was particularly important once artillery was introduced to naval warfare. The ships heeled away from the wind so that the leeward vessel was exposing part of her bottom to shot. If damaged between wind and water, she was consequently in danger of sinking when on the other tack. See Spanish Armada.

• Windward Islands, Leeward Islands and Leeward Antilles (in the Lesser Antilles).
• Northwestern Hawaiian Islands, also known as Leeward Islands.
• Windward Islands and Leeward Islands (in the Society Islands).
• Barlavento (Windward) and Sotavento (Leeward) in Cape Verde Islands.
• Lee shore
• Downstream and upstream

1. ^ Jones, Daniel (1997). English Pronouncing Dictionary, 15th edition, Cambridge: Cambridge University Press. ISBN 0-521-45903-6. 
2. ^ The American Heritage Dictionary of the English Language

Look up windward, leeward, upwind in Wiktionary, the free dictionary.

• Directions on a sailing boat