foresail

A foresail is any sail set forward of the mainsail on a sailing vessel. In common sailboat terminology, it refers to the headsails that work with the mainsail to drive the boat upwind or on reaches. The foresail is typically attached to rigging at the bow, such as a forestay, and its trim and size affect balance, pointing ability, and maneuverability.

Common foresails include the jib, a triangular sail attached to the forestay; and the genoa, a larger headsail that overlaps the mainsail and provides more power in light winds. A staysail is a smaller triangular sail set on a stay between the bow and the mast, often used with a jib or genoa for additional sail area and stability. Some rigs, such as cutter rigs, carry multiple foresails (for example, a jib and a staysail) to adapt to changing conditions. In modern boats, foresails are frequently fitted with roller furling for easy handling and reefing.

Rigging and handling: Foresails are controlled by sheets at the clew and a halyard to raise or lower the sail. The luff is secured along the forestay or a forestay portion, and the headsail size and shape are tuned to the sail plan and wind conditions. A larger foresail increases upwind power but can induce weather helm if not balanced by the mainsail and helm inputs.

Summary: The foresail is a key component of a sloop, cutter, and many other rigs, providing essential upwind performance and balance, with jibs and genoas being the most common forms.