A sailboat is a wind-powered vessel whose sole or primary source of power comes from the use of sails to move atop and through water. As a sailboat, when solely under the power of sail, the vessel enjoys certain navigational benefits such as right-of-way privileges. However, if supplemental power from a diesel or gas powered engine is used, whether for docking or other precise maneuvers, a sailboat technically becomes another power-driven vessel and is subject to power boating rules.
In the same way that highway motorists must abide by certain laws and regulations governing the rules of the road, every boater, whether in a sailboat or powerboat, must be informed concerning navigational rules. To learn more, a good start is to acquire a copy of the “U.S. Coast Guard’s Navigation Rules, International-Inland” which can also be obtained at most marine store outlets.
The twin forces of aerodynamics and hydrodynamics work together to propel a sailboat through the water. As the wind strikes the sails and the underwater parts of a sailboat engage with the water, movement is created. Learning how to maximize these forces to steer an intended course comprises much of the skill and craft necessary to operate a sailboat.
A sailboat will have one or more sails affixed by lines to other parts of the boat, usually to a mast (a vertical pole) and/or boom (a horizontal pole) but also to lines routed to winches (mechanical winding devices) or cleats (fixed fittings for tying). Operating these devices in order to manipulate the position, shape and size of the sail(s) in relationship to the direction of the wind is called "trimming the sails."
If a sailboat were to rely solely on the force of wind upon the sails for direction of movement, then the direction of movement would forever be the same as the wind. When a sailboat moves in the same direction the wind is blowing or at slight variations to it, it is termed as "running before the wind" or "running." However, when a sailboat must sail to some degree into the wind, it is called "beating," "tacking," or "heading up" and must utilize the added dynamic of a keel or centerboard.
Keels and centerboards are sturdy underwater extensions protruding from the bottom center of the sailboat. The keel is a fixed extension and is usually found on larger sailboats. A centerboard, sometimes called a "dagger board," can either be a pivoting type or dagger type and is retractable. In each case, the extension works to force a resistance counter to the force of wind upon the sails and results in a new direction of movement. Without a keel or centerboard, the sailboat would move sideways only and likely tip or capsize.
The ship’s wheel or tiller arm (a handle in place of a wheel) connects via lines and blocks (pulleys) to the underwater rudder (steering blade) located at the rear (or stern) of the sailboat to comprise the helm, which completes the assortment of devices necessary to purposely steer and direct a sailboat through and atop the water.