Double-line reefing is a method used to reduce the area of a sail, making it easier to handle in strong winds. This technique involves using two lines to secure the sail to the boom, allowing for a more controlled and efficient reduction of sail area. By pulling on these lines, sailors can quickly and effectively reef the sail without needing to lower it completely. This method is particularly useful for larger vessels, where managing the sails can be challenging. Double-line reefing helps maintain balance and stability while sailing, ensuring that the boat remains safe and maneuverable in changing weather conditions.