Sailing School: How does a sail work?

We all know what a sail is on a boat, but do we actually know how they work?

Sails are, in essence, the means by which to use the wind to generate enough force to move a boat.

Generally sails are built from a flexible material which allows them to use the wind on both sides in order to allow the boat to change direction. The material needs to be flexible and be able to support itself in the wind, which is why the traditional triangular shape is mostly used.

Sails work by deflecting air and using airflow from the wind and the motion of the boat to generate force.

In very basic terms, what happens is that a sail generates lift using the air that flows around them, just as an airplane’s wings work. The wind that flows over the surface of the sail, then creates a force approx perpendicular to the sail and this force when parallel to the keel of the yacht will propel the boat forward.

A sail will always have a smooth surface as if it was rough then the friction would cause the wind flow to slow down.

To understand more about how this all works, then get yourself onto a yacht course with our sailing school at universal sailing school, and you’ll soon understand all the science!