A sail-plan's a set of drawings, usually prepared by a naval architect. It shows the various combinations of sail proposed for a sailing ship. The combinations shown in a sail-plan almost always include three configurations: A light air sail plan. Over most of the Earth, most of the time, the wind force's Force 1 or less. Thus a sail plan should include a set of huge, lightweight sails that'll keep the ship underway in light breezes. A working sail plan. This's the set of sails that're changed r… (More on Sail-plan)