Foot

The lower edge of a sail, typically attached to the boom or deck of a sailing vessel.

The term foot refers to the bottom edge of a sail. On a fore-and-aft rigged sail, such as a mainsail or jib, the foot is the edge that runs along the boom or, in the case of some headsails, along the deck or bowsprit. The foot of the sail plays a crucial role in the overall shape and performance of the sail, as it helps to control the flow of wind across the sail’s surface. When the sail is properly trimmed, the tension along the foot can be adjusted to optimise the sail’s efficiency, particularly in different wind conditions. For example, easing the foot tension can create a fuller, more powerful sail shape, which is useful in lighter winds, while tightening it can flatten the sail, reducing drag in stronger winds.

In traditional square-rigged vessels, the foot of the sail is the bottom edge of the square sail, often attached to a spar or yard. The foot is an essential part of sail handling and trimming, as it directly influences the sail’s ability to harness wind power effectively. Understanding the dynamics of the foot, along with the other edges of the sail (luff and leech), is key to efficient sailing and manoeuvring.