A staysail is a type of sail that is set on a stay, which is a cable or rope that supports the mast of a sailing vessel. It is typically triangular in shape and is used to enhance the boat's performance, especially when sailing upwind. Staysails can be found on various types of boats, including yachts and tall ships. Staysails are often used in combination with other sails, such as the mainsail and jib, to improve stability and control. They can be furled or unfurled as needed, allowing sailors to adjust their sail plan based on wind conditions. This versatility makes staysails an important component of a sailing rig.