Leeward

The term "leeward" (pronounced LEW-erd or LEE-wərd) describes the direction downwind from a given point of reference. As defined in Wikipedia, leeward is the side or direction towards which the wind is blowing, serving as the opposite of windward.

In seamanship, a clear distinction must be made between the leeward side of a vessel and a leeward shore (commonly called a lee shore). A yacht’s leeward side (or lee side) is the side opposite to where the wind originates; as the boat heels under sail, this becomes the lower side. Conversely, a leeward shore is land positioned downwind of the boat. While the lee side of a hull offers shelter from wind and spray, a lee shore presents a grave hazard to navigation because wind and sea state continuously drive the vessel toward shallow water or rocks.

Leeward positioning also governs right-of-way under Rule 12 of the International Regulations for Preventing Collisions at Sea (COLREGs). When two sailing vessels have the wind on the same side, the vessel which is to windward must keep out of the way of the vessel which is to leeward.

Executing basic maneuvers such as tacking and gybing requires smooth control of sails as they swing across the leeward side. To counter leeway—the sideways drift toward leeward caused by wind pressure—modern hulls rely heavily on effective sailboat keels to provide hydrodynamic lift and directional stability.