How to Sail on the Lifted Tack

How do sails work? There are many things you have to know about sails. Many people think that you go fastest downwind (when the wind is coming from behind you). This is very wrong. Think of a sail as an airplane wing. An airplane wing is curved on a side. That makes that side longer. When air passes the wing, it moves faster on the long side to try to keep up with the short side’s air. This makes the air on the curved side have less pressure, creating lift. This works on a sail too.

But if the sail is parallel to the direction of the boat and there is lift toward the long side of the sail, how does the boat go forward? You would think it would go sideways. That’s where the centerboard comes in. The centerboard is a long board sticking into the water. Along with helping keep the boat flat, it creates sideways resistance. This means that it would be harder for the boat to go sideways. Since the sail is always facing a little bit forward, the boat’s easiest course is forward. This may be a little hard to grasp. It was for me. That’s why I made a diagram in paint (sorry for the bad drawing).

So now that we know how the boat moves, we have to figure-out how to make it move fast. This involves pulling on those magical things called sheets. They help control the sail. The closer your bow is to the direction the wind is coming from, the more you pull your sail in. If your bow is about 45 degrees to the wind, it is called close-hauled. When you are close hauled, you want to bring your sail all the way in. When you are 90 degrees to the wind, it is a beam reach. This is the fastest way to sail. When you are on a beam reach, you want to let your sail out about 40 degrees (from close-hauled). When you are about 135 degrees from the wind, you are on a broad reach. When you are on a broad reach, you want to have your sail out about 70 degrees (from close-hauled). When you are going 180 degrees from the direction of the wind, you are going dead downwind. When you are going dead downwind, you will want to have your sail as far out as possible. You may even want to have your crew push it out. These “degrees” are called points-of-sail. When your point-of-sail is higher (in degrees) than 90 degrees to the wind, you will want to take your centerboard half-way up. I’m going to assume that was confusing as well, but I’m afraid my drawing-on-the-computer-skills are all washed up, so here is a link to a picture: www.sailing-obsession.com/ points%20of%20sail.JPG. But wait! What if your boat is pointing closer than 45 degrees to the wind? Do you trim in your sail even more? No. The area in which you are closer than 45 degrees to the wind is called the no-go-zone. If you are in it, you won’t move. So don’t go in it.

You are now skilled in sail trim. Good job!