by Andre Sanchez

When learning how to sail a boat, tacking and jibing are the two basic means by which you will make way into and with a wind.  When sailing into the wind there is an area of about 35 degrees that the boat cannot sail into.  In order to progress it has to sail to either side of that vector, changing direction from time to time in order to make progress in the direction intended.  The boat is basically sailing a zigzag course rather than a straight one.

It was only with the development of triangular sails that this was possible, and ships rigged with the old square sails were unable to carry out this maneuver, known as ‘tacking’.  In addition to a triangular sail, a boat also needs a centreboard, or long keel, to tack effectively, in order to prevent it from being pushed sideways in the direction of the wind.

The way it is done is to travel for while at an angle to the required curse, as close-hauled to the wind as possible, then swing the boom of the sail to other side, and tack to the opposite side of the vector for a while. In this way you can use the wind to its best advantage, and travel in any direction you want.  Prior to tacking being able to be used, vessels had either to stop, or to sail long distances off course, than come back when wind conditions were favorable.  However, the way that a boat can use the wind like this confuses many people, since it does not seem logical that a boat can sail into a wind.

It is all down to mathematics and sail and keel design.  When wind blows at right angles to a boat the large keel stops it from being pushed sideways. Then force of the wind on the keel is then aligned forwards so the boat moves forwards.  It is due to the thrust vector along the keel. However, it is not all due to the keel since the sail also provides a forward thrust, even when sailing into the wind.

Due to its triangular shape, the sail forms an airfoil when inflated with wind, that creates pressure differences between the two sides of the sail.  A triangular sail on a sailing boat, when filled with wind, has a cross section similar to that of a wing, and is that airfoil shape that drives the boat.  As negative pressure is formed on the leeward side of the sail, air rushes into it and so drives the boat forward.  Then, as the boat moves faster, this effect is increased and has an increasingly larger effect on the propulsion of the boat.

The combine effect of the airfoil and the vector force on the keel is that the boat can travel at speed at right angles to and into a wind.

Turning the boat, to sail in the opposite direction, is called ‘coming about’.  How this is done depends on the size of the boat and any crew.  First you have to close haul the boat till it is almost into the 35 degree vector, and while you are going forward slowly push the tiller and when the boat becomes level (straight into the wind), ease the trim, then move to the other side of the boat, changing hands for tiller and mainsheet, and straighten up the tiller.

If you have crew, they will ease and reset the jib so that the boat will not stop. You should now be sailing with the wind and at full speed ahead!  However, your boat will be very difficult to control sailing directly into the wind, and you will have to start zigzagging again.  In this case it is called jibing.

When you jibe, you turn away from the wind rather than into it.  This can be very tricky since you are liable to be sailing quite fast at the time and it is not easy to take off power and speed without turning back into the wind.  Also, since you are turning with the wind, your sail will be fully out, so it will have to be swung across from fully out one side to the other. 

Turn the boat and let the sail slowly out.  As the boat become nearly exactly with the wind, start to pull the sail back.  This will prevent any sudden sail movement when the wind fills it again.  Keep in mind that it will move pretty fast, so duck and keep below the level of the sail.  Once the wind hits it, the sail will rapidly swing across while you try to slow it down by maintaining tension on the mainsheet. Once the boat has turned past the downwind point, then let the mainsheet out and trim the sail.  This is a more difficult maneuver than tacking due to the power that is in the sail, and if you are not careful you can get a nasty knock. 

Taking and jibing are basic skills in learning how to sail a boat, and you not be able to sail alone without them.

How to Sail a Boat: Tacking and Jibing was originally published at http://www.globallifenow.com