sailplan

A sailplan is the arrangement of a sailing vessel's sails, masts, and rigging as designed to achieve specific performance and handling characteristics. It specifies which sails are used at different points of sail and how they are supported by spars, standing rigging, and running rigging. Sailplans are used by designers, shipwrights, and sailors to understand and communicate a vessel’s rigging and sailing capabilities.

Rig types range from fore-and-aft to square-rigged configurations. Fore-and-aft rigs include the sloop, typically with one mast carrying a mainsail and a headsail; the cutter, also on a single mast with multiple headsails (often including a staysail); and the schooner, with two or more masts bearing fore-and-aft sails. Square-rigged ships carry square sails on their masts, common in traditional sailing ships; smaller craft may be described as brig or brigantine. A ketch has a second mizzen mast with the mizzenmast forward of the rudder post, while a yawl features a mizzen mast aft of the rudder post. Modern yachts frequently employ Bermuda (or Marconi) rigs, which use triangular mainsails, and may combine with gaff, lateen, or junk rigs in various configurations.

Sailplans influence performance and handling by determining sail area distribution, the center of effort, and balance between hull and rig. Designers use sailplans together with hull form, weight distribution, and ballast to predict stability, speed, and weather helm. For sailors, the sailplan guides choices of sails for different wind conditions and informs reefing, hoisting, and dousing procedures during a voyage.

In naval architecture, sailplans are often represented by diagrams showing mast positions, sail types, and sail areas, ranging from simple layouts for small craft to complex configurations for racing and cruising yachts.