An uphaul is a line (rope) attached to the boom or mast used in windsurfing to pull the sail up out of the water, allowing the sailor to start sailing. It is a long, often elasticized cord handled hand-over-hand to raise the rig while the sailor stands on the board.

Key Aspects of the Uphaul:
Windsurfing Function: It is essential for beginners and casual sailors to transition from a resting position in the water to a sailing position.

Technique: To use, the sailor keeps their back straight, legs bent, and uses their legs to lift rather than their arms, pulling the rope hand-over-hand while keeping the sail in the water initially to drain, which reduces weight.

Other Uses: In some contexts, it can refer to a line used for raising a centerboard or occasionally a topping lift that supports a sailboat boom.

It is generally distinct from the downhaul (which tightens the sail down the mast) and the outhaul (which pulls the sail out to the end of the boom).