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ASA 101 Sails & Sail Controls

· sailing,ASA101

To prepare for your ASA 101 exam, you should know how to identify and describe the functions of the following sails, sail parts, and sail controls:

Sail Sides

The front leading edge of a sail is called the luff (which comes from the middle dutch word "loef"), while the back edge is called the leech (which comes from Old Norse). The bottom edge of a sail is called the foot.

A useful trick to help you remember the difference between luff and leech is to picture a sail in your mind, and then think about the first thing that comes to mind when you think leech or luff. Often, people may think of the blood sucking leech animal. Picture the animal on the aft (back) edge of the  sail. Research shows that mental images like this are much easier to remember, especially when they are vivid or evoque emotions, such as imaging a disgusting blood suck leech on the back of your sail.


A halyard is any line (i.e. rope) used to raise or lower a sail or other object, like a flag. 

Boom Vang

The boom vang is responsible for holding the boom down, giving the sailor control over the shape of the sail. When sailing close to the wind, such as on a closed haul, the mainsheet will usually do a good enough job applying downward force on the boom. However, as you move away from the wind (i.e. reaching or running), the mainsheet exerts less and less force on the boom and this is where the boom vang becomes useful. Trimming the boom vang correctly will get more performance out of the mainsail — make sure not to overtighen it however, a good tug is usually sufficient.

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