Identifying the Points of Sail

The points of sail diagram looks like the face of a clock, with the wind blowing from 12:00. At the top of the clock face, from about 10:30 to 1:30, is the sector called the no-sail zone. It gets its name from the fact that it's physically impossible to sail a boat in this zone. You can call the no-sail zone whatever you like — the can't-sail zone or the anti-sail zone or, if the sun is setting and strange things are happening, the Twilight Zone. Pointing your boat anywhere else around the clock face is fair game — with the sails trimmed properly, you move forward. This "sail zone" further divides into three basic points of sail:

• Close-hauled: Also called beating, sailing upwind, or sailing to windward, it's the closest course to the wind that you can effectively sail on the very edge of the dreaded no-sail zone. So close-hauled is right at 10:30 and 1:30.

• Reaching:Anywhere between close-hauled and running.

• Running: The course you're steering when the wind is dead behind. Exactly 6:00 on the clock face if you're a stickler — from 5:30 to 6:30 if you're like us.

More about that darn no-sail zone

The no-sail zone is about 90 degrees wide — about 45 degrees on either side of the wind direction, or from 10:30 to 1:30, if you like the clock. In this zone, a sailboat can't generate power from its sails and will coast to a stop. The problem is that your sails luff (flap) even when you pull them in all the way.

As you enter the no-sail zone from the sail zone, the front edge (luff) of your sails start luffing a little bit (it looks like the front of the sail is bubbling), and you start to slow down. If you turn to the very middle of the no-sail zone, your sails flap like flags, and your boat quickly coasts to a stop. In fact, if you stay in the no-sail zone too long, the wind blows your boat backward, which is called being in irons. Getting in irons happens to every first-time sailor.

But the beauty of sailing is that you have a way around this apparently forbidden territory. To get to a destination directly upwind in the no-sail zone (say 12:00), you can take a zigzag route, sort of like hiking up a very steep mountain. This technique involves sailing close-hauled and periodically tacking (a maneuver where you turn the boat from 1:30 to 10:30 or vice versa). With this knowledge, you can literally sail wherever you want!

You must be very clear on one point: No boat can sail a course directly into (toward) the wind. If you try to do so, the sails start luffing, no matter how tight you try to trim them — like they do when the bow is pointed into the wind at the dock. The boat glides to a stop and eventually blows backward, like any object floating on the water.

Why is the no-sail zone 90 degrees?

The size of the no-sail zone is slightly different for each boat. Some racing boats with very efficient sails and keels can sail as close as 30 degrees to the wind. For them, the no-sail zone is around 60 degrees wide (the angle from close-hauled on one side of the zone to close-hauled on the other). The wind strength also affects the size of the no-sail zone. In very light air, all boats go slower, and the foils (the keel, rudder, and sails) are less efficient, so you sail a wider angle to the wind than you do in stronger winds.

Sailing in the zone

Sailing in any direction in the sail zone is as easy as trimming the sail (by pulling in on the control rope — the sheet). Or you can just cleat the sail(tie off the control rope so that the sail stays in one place) and turn the boat away from the wind direction until the sail fills. The points of sail diagram shows boats sailing at all different angles to the wind in the sail zone.

To sail fast, trim the sails to the proper angle to the wind. You pull the sails in tight when a boat is sailing close-hauled and let them out all the way when on a run.When you're reaching, the in-between point of sail, trim the sails in between. Makes sense, huh?

Keeping your sails properly trimmed is important for maneuverability. Any time your boat slows down, you must be extra vigilant because a very slow boat can lose steerage on any point of sail. Don't just stop in a waterway unless you have plenty of room to regain your forward motion.

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Source:http://www.dummies.com/how-to/content/identifying-the-points-of-sail.html