A sailboat is a boat whose primary source of propulsion is wind in its sails. It is also steered by means of the keel, a fixed underwater part that provides stability and prevents the boat from drifting sideways. In addition, a sailboat can be trimmed to balance its load and performance by changing its rig.
The rig refers to the arrangement of masts and sails. The most common sailboat is a monohull, but there are other types including catamarans and trimarans that have multiple hulls. Each hull is made of fiberglass, metal, or wood.
As a boat moves through water, the bow wave creates a series of crests and troughs that move with the speed of the boat. As the wavelength (length of the full wave) of these waves decreases with increasing boat speed, the troughs become shallower and the crests more steep. This is what causes drag on the boat and slows it down.
This force is offset by the water forces that act upon the keel, which is fixed below the boat to provide ballast (counterweight) to the boat and prevent it from drifting sideways. In addition, the shape of the keel itself can produce forces that accelerate the boat’s motion.
When the keel is angled down on one side and up on the other, the flow of water around it generates vortices behind the bottom rear of the keel. This acceleration produces the same driving force as the wind in the sails. However, it is not able to overcome the resistance of the boat’s hull and keel. As a result, a sailboat cannot be sailed directly into the wind. Sailing involves a number of steering maneuvers, known as tacking, that allow the boat to sail in a zigzag pattern across the direction of the wind without ever sailing directly into it.
Auto Amazon Links: No products found.