Furling

The action or equipment used to gather, roll or fold a sail into a stowed or reduced state.

Headsail systems commonly rotate a foil or stay, while in-mast and in-boom systems roll a mainsail inside or along a spar. Traditional furling instead lowers and secures the sail without a rotating mechanism.

A furling system eases handling but adds bearings, drums, swivels, lines and sail-shape requirements that can jam or be overloaded. Only systems and sails designed for partial deployment should be used for reefing, and maintenance and emergency-unfurling or sail-lowering arrangements remain necessary.