Lazy jacks are a web of lines that run from the mast to the boom in order to capture the mainsail when it is lowered. Lazy jacks work much better with fully battened mainsails since the battens help keep the folds of sail inside the lazy jack lines. When the main halyard is lowered, the sail falls between the port and starboard lazy jack lines. If the lazy jacks are left deployed when the sail is lowered, a custom fitted sail cover will be needed that attaches around the lazy jacks. A standard sail cover can be used if the lazy jacks are loosened and pulled forward once the mainsail has been flaked and secured with sail ties.