Sail plan

[2][3] A sailing craft may be waterborne (a ship or boat), an iceboat, or a sail-powered land vehicle.

The sail plan may provide the basis for calculating the center of effort on a sailing craft, necessary to compare with the center of resistance from the hull in the water or the wheels or runners on hard surfaces.

Such a calculation involves the area of each sail and its geometric center, referenced from a specific point.

A cutter-rigged yacht, intended for off-shore sailing might have a sail inventory that includes: a mainsail, a roller furling genoa, and a working staysail for most wind conditions, and, for strong winds, a storm staysail and trysail.

Their naming conventions are:[7] In the late 19th and early 20th centuries, choosing a sail plan for a displacement watercraft stemmed from the size and tonnage of the vessel, its purpose (working vessel, cargo vessel or yacht) and the anticipated winds in the region where it was expected to sail.