SAIL'S BEST LITTLE LEARN TO SAIL BOOK EVER Page 2
Points of sail
The angle of sail is the difference between the direction your boat is heading and the direction of the wind. Different angles of sail, called points of sail, change as your boat changes course, and the sails must be adjusted to harness the wind as efficiently as possible. When sailing as close to the wind as possible, with the sails trimmed in all the way, you are close-hauled or beating. As you bear off, steering away from the wind, you will ease your sails as you sail onto a close reach, then a beam reach (where the wind is blowing over the side, or beam, of the your boat), then a broad reach. When you are sailing directly away from the wind, you are sailing on a run with your sails eased all the way out. If you continue to turn, you will gybe, so that you are on a run with your sails on the opposite side of the boat. As you gradually head up, turning toward the wind, you will need to trim your sails to keep them from luffing (flapping in the wind) as you sail onto a broad reach, then a beam reach, close reach, and finally back up to close-hauled.
Wind is the movement of air from areas of high pressure to areas of low pressure. While air is made up of gases, in many ways it behaves like a liquid. It flows over and around obstructions, seeking the path of least resistance. Wind will blow more strongly out of valleys and will be almost nonexistent on the leeward side of a high hill.
The wind is rarely perfectly steady. Depending on the surfaces it passes over, the stability or instability of the air, weather systems, and even the effects of other boats, the wind is constantly changing in both strength and direction.
The wind itself is invisible, but its effects are not. When you're sailing, it's important to be aware of the strength and direction of the wind in order to harness its energy efficiently and sail safely.
There are many ways to tell the direction of the wind. Wind blowing across water causes friction on the surface, forming small ripples perpendicular to the direction of the wind. (Larger waves are caused by the longer-term effects of the wind and current.) Learning to determine the wind's direction by looking at the water's surface takes much practice, but it's the most accurate method. Other helpful indicators are flags, smoke, and other sailboats.
There are simple tools that can help you find the direction of the apparent wind. Telltales are lengths of yarn or strips of nylon tied to the shrouds and backstay. A masthead fly, with a wind arrow, goes at the top of the mast and points into the wind.
You can also use your sails to find wind direction. When you ease your sails, they will luff and line up with the wind. Gradually turn your boat toward the wind; you'll be straight head-to-wind when the sails are luffing on the boat's centerline.
One telling indicator of wind strength is when whitecaps (white tufts on the waves) just begin to form. This occurs at around 12 to 14 knots, a point at which many small boats begin to get less stable. Inexperienced sailors shouldn't be out alone when there are whitecaps.
Sailing close-hauled (beating)
A boat can't sail directly into the wind, but it can sail toward the wind, as close as about 45 degrees off the wind's direction. As you turn toward the wind from a beam reach to a close reach to close-hauled, you must gradually trim your sails to keep them from luffing. Once the sails are trimmed in all the way, your steering keeps them from luffing. Steering as close to the wind as possible with your sails fully trimmed but not luffing will allow you to progress most efficiently in the direction of the wind.
Sailing close-hauled is perhaps the most difficult point of sail. When reaching or running, you simply point your boat in the direction you want to sail and adjust the sails to maximize their efficiency. But since the wind is not always from a steady direction, you now need to adjust your course rather than the sails.
With the sails trimmed in all the way, head up slowly toward the wind until the luff of the jib (or the luff of the mainsail, if you have only one sail) just begins to luff. Then bear off slightly, steering away from the wind (tiller away from the sails) until the sail just stops luffing. Sailing the boat with the luff of the jib on the verge of luffing will keep you in the close-hauled "groove."
A common mistake is to bear off too far away from the wind with your sails still trimmed for a close-hauled course. While your sails will appear to be full of wind, they will actually be stalled, with little airflow over the back side of the sails. Use the telltales on the luff of your sails as early-warning signals. When the telltale on the leeward (or back) side of the sail starts jumping around, it's telling you it's stalled and that you must either head up or ease the sail.
Begin sailing on a reach by picking a distant point to aim for. Experiment with steering, gradually heading up and bearing off, while you adjust the sails for your course. Sail a serpentine course from a close reach down to a broad reach and back. As you bear off you should ease the sails, and as you head up, trim the sails.
Running with the wind
Running with the wind is perhaps the most relaxing point of sail. Since the wind is not blowing across the boat, there is no sideways (or heeling) force. As you bear off from a beam reach to a run, you ease out the sheets so the sails catch as much wind as possible to push you along.
On a run, the boom will be close to a 90-degree angle to the boat, and the mainsail will block the wind to the jib. You can get more wind by flying the jib wing-and-wing, with the jib pulled to the side opposite the main. Here’s how: Hold the jibsheet out to windward, by hand on a small boat or with a whisker pole on a larger boat. The jib fills with wind, and you're off.
If your boat has a centerboard, you'll want it raised when you're running. When you are running straight with the wind, you don't need any help from the centerboard to keep from sliding sideways, but a little board helps reduce side-to-side rocking. As you bear off, begin to raise the centerboard—approximately one-third on a beam reach and up to two-thirds on a run. Lower the centerboard before you head up.
Caution! Beware of the unexpected gybe; it can be dangerous. Always be aware of the boat's angle to the wind. When the jib will not fill with wind, or when you are wing-and-wing, an accidental gybe is possible. Don't bear off further than straight downwind unless you plan to gybe. If you're in doubt, head up toward a broad reach.