Windsurfing 101 ... Sails Part 1 - Anatomy Of A Sail

Sails:

The triangular Dacron sails are now the thing of the past! They have been replaced with a design that is lighter, more performing, much easier to use and will bring to the level of eventual maneuvering and speed. They no longer just have a beginner’s use, and can last you as long as your needs can carry them.

Now we’re going to examine the anatomy of a sail. Before you go out and purchase something, let’s get you familiar with the terms.

The Anatomy of A Sail:

We have taken the liberty of using a North Sails Drive as an example of a beginner/free ride sail.

HEAD (Some sails may have adjustable heads)

Masts come in stock sizes - 400cm; 430cm; 460cm etc. However, your mast may not necessarily fit the sail properly because it is a touch too long. This is where an adjustable head comes into play. Many sails below 6.0m are available with an adjustable head strap which allows the sail to fit exactly on the mast. These adjustable head straps are either made of a webbing or a molded plastic cap or both.

BATTENS

Battens give rigidity and shape to the sail. All the main body battens are tapered so that they bend more at the luff end, thus pushing the fullness towards the front of the sail.

LUFF

This is the 'front' of the sail; the first part that the airflow encounters. The Luff Sleeve is the sleeve where the mast fits.

BOOM CUT-OUT

The area cut out of the luff sleeve to allow the boom to be clamped to the mast.

TACK

The very bottom of the sail, nearest the mast - usually the point at which the tack cringle (eyelet or pulley system for the downhaul fitting) is located. There may be a tack handle to assist pulling the sail onto the mast.

DOWNHAUL

This is the main method of tensioning the sail, and is most important for securing the bottom of the sail to the mast foot once it has been sleeved onto the mast. Modern sails have either a steel eyelet or pulley system, to allow the downhaul rope to feed several times between the pulleys on the mast foot and the pulleys either on the sail or built onto the hook put through the eyelet.

FOOT

The bottom edge of the sail, between the tack and the clew.

CLEW

The 'back corner' of the sail which is also the fixing point for the back end of the boom. The fixing is almost invariably an eyelet, through which rope from the back end of the boom can be passed.

FOOT BATTEN

All sails have at least one batten that goes from the luff to the foot, rather than to the leech. As the foot batten is often orientated at a different angle to the other sail battens, it is often made easier to remove, and will always have a different batten tensioning system, so there are no protruding edges to stick into the deck of the board or the feet !

LEECH

The back, or 'trailing' edge of the sail, between the clew and the head which effects the sail’s range of use (how little or how much wind a sail can take before getting under-powered or over-powered).

BATTEN TENSIONERS

Setting and keeping the right tension in the battens is very important, so a lot of ingenuity has been employed in coming up with functional systems. Some brands and older sails still use straps and buckles, but these can slip, which is why most brands use allen key screw-fasteners. Unlike the strap and buckle system which must be adjusted and tightened every time you rig the sail, the allen-key system allows you to tighten the battens only when necessary.

Now that we have the basic anatomy of the sail figured out, let’s attack how the sail actually works in the wind. Keep in mind that this is a basic rundown without going into too much detail.