You need to alter the angle as you sail when the wind changes. Otherwise you will lose that forward motion that you want. Adjusting the sails is called trimming them. You do this by adjusting the tension of the line, called a sheet, attached to the sail. When you pull the sheet in, it moves the sail towards the center of the boat. When you let the tension out, or sheet it, it lets the sail out. It can be hard to master trimming the sails.
The wind is rarely cooperative. It may come in at constantly changing angles. You will need to adjust accordingly. This is a learning process, and no one is an expert sailor their first time out. It can be hard to trim the sails when you are sailing upwind. The angle of the sail needs to be just right to allow proper airflow. If you have sheeted too far out or in, it will not work. You will not get that wing shape you want, and you will stall out in the water. The easiest way to trim your sails upwind is by trial and error.
Sheet your sails out until they flap loosely. This flapping is called luff. Then sheet the sail back in slowly. Watch the shape and tension of the sail. When it smooths out and curves there is no more luff. This is where you want it to be. Turning upwind is called heading up. Sometimes it is called bearing up or pointing up.
If you push the tiller towards the sail and away from yourself, you are turning upwind. The sails need to be trimmed along with the turning. The angle of the wind is going to change. If the sails are not sheeted, you will lose the wind. Treat winds perpendicular the same as upwind. The process of trimming the sails will be the same. Smooth out the luff and proceed on course once you have that wing shape. Despite what you may think, trimming sails downwind can be hard.
The sails will naturally parachute or balloon in the wind. To control them takes work. You need to try to get the sail perpendicular to the wind. This will expose the maximum surface of the sail. Thus, you get the most lift. Again, this is a trial and error process to get it right. Turning downwind is also called falling off. This is also called bearing away or pointing down.
You do this by turning the tiller towards yourself and away from the sail. Like turning upwind, the sail needs to be adjusted. You will have to sheet out to maintain your course. When you want to sail into the wind, you need to engage in what is called tacking.
A river runs straight from West to East at 10 knots. A 10 mile race is held: the boats sail downstream, from West to East. The first heat is held in the morning, when there is no wind. The second heat is held in the afternoon, when there is a 10 knot wind from the West.
In which heat are the faster times recorded? Answer below. Sailing downwind parallel to the wind, like the boat at left is easy to understand: the wind blows into the sails and pushes against them.
The wind is faster than the boat so the air is decelerated by the sails. The sails push backwards against the wind, so the wind pushes forward on the sails.
But for a boat with normal sails, the catch is that, downwind, you can only ever sail more slowly than the wind, even with a spinnaker. Which is comfortable, but not the most interesting sailing. You know this force: In a strong wind, it is easier to walk, run or bicycle with the wind pushing on your back. Usually, the wind pushes you in the direction it is going. Sailing directly upwind exactly anti-parallel to the wind, like the boat at right is also easy to understand: it's impossible impossible with sails: a boat with a wind turbine driving a propellor could go directly upwind.
You just sit there with your sails flapping. This is also not interesting sailing. So let's think about In this diagram, the quantities force and velocity have arrows, because they have a magnitude as well as a direction. Try this link for an Introduction to vectors. Note that nowhere in this argument did we need to say that the wind was faster than the boat.
Now this force is mainly sideways on the boat, and it gets more and more sideways as you get closer to the wind. However, part of the force is forward: the direction we want to go. Why doesn't the boat drift sideways? Well it does a little, but when it does, the keel , a large nearly flat area under the boat, has to push a lot of water sideways.
The water resists this, and exerts the sideways force F k on the keel. This cancels the sideways component of F w. A little digression: the sideways components of wind and water on the boat make the boat heel tilt away from the wind, as is shown in the diagram below.
These two horizontal components have equal size but opposite direction: as forces they cancel, but they make a torque tending to rotate the boat clockwise.
This is cancelled by another pair of forces. 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.
Read more tips Sails and Sailhandling Systems here. Wind is the movement of air from areas of high pressure to areas of low pressure. While air is made up of gasses, 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. 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.
The easiest point of sail, and often the fastest, is the reach. Start off with the wind blowing across your boat. As a general rule for trimming sails, ease the sheet of each sail out until the luff or front edge of the sail begins to luff thus the name.
Trim it in until the sail just stops luffing. The goal is to keep the sail trimmed so that it is eased as far as possible without luffing. 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 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 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. 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.
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