At first sailing might seem to be a physically unnatural activity. It is easy to see how one can sail with the wind as the breeze creates a force that pushes the boat through the water. Sailing into the wind is a totally different action. When sailing into the wind the sails become foils, not unlike the wings of a glider. The wind flows across them, creating a pressure difference, which creates a lift force. Simply, that is what moves the boat forward into the wind.

A boat cannot sail directly into the wind. Most sailboats can point to approximately 45 degrees off the true wind. If a boat points directly into the wind it will lose all its force, stop and eventually move backwards in the water. A boat that does this is said to be "in Irons", a place no sailor wants to be except in extreme circumstances.

The direction a boat is moving is called its Point of Sail. The three main points of sail are:

Beat: (also know as close-hauled) where the boat is traveling as close as possible to the wind.
Reach: in which the wind is coming to the boat from the side.
Run: where the wind is almost directly behind the boat.

Click on the image below to view the Parts of the Boat (will open a new window)

Beating, as it is called, is sailing as close to the wind as possible without luffing, a slight fluttering of the edge of the sail, resulting in a lose of power. If the direction you want to go is directly up wind the boat must be zigzagged toward the destination. The movement from one side to the other, into the wind, is known as tacking or coming about. This accomplished by turning the boat, by redirecting the rudder, so that the bow goes through the wind and the sails are moved to the opposite side of the boat.

Reaching ranges from a close reach, just a little further off the wind than a beat, to a broad reach there the sails are set more than 90 degrees off the wind. Reaching is usually the fastest point of sail.

Running is sailing with the wind almost directly behind the boat. Because the wind is pushing from behind, the boat will usually sit fairly flat in the water. To change direction while running a boat must jib instead of tacking. Jibing moves the stern or back of the boat through the wind, not the bow. Jibing can be potentially dangerous as an uncontrolled boom can swing across the boat, hitting anyone in the way. The captain and crew must always watch out for an unintentional jib.

Sail Control

Setting the sails so that they take the best advantage of the wind and the boat moves most efficiently in the water is called sail trim.

The lines that control sails are called sheets. The main sheet controls the main sail. Two jib sheets, a port and a starboard jib sheet, control the jib.