SPEED

TOM-WHWhy are some people so much faster, even when they are using a smaller sail?

KUROSH-WH

It is also very noticeable the difference in the speed of the average sailor and the Pros.

BALANCE.

We need the power/engine which is the sail. It needs to pull but also needs to generate drive. So yes we have pull when we start to get plaining but as you accelerate the sail is working on aerodynamics and needs pressure. A common phrase I here is “I have no power or I am under powered”.  You can always rig your sails to give you pull, just let off the downhaul and out haul but this normally does not give you drive. So I like to call it pressure as so often I am planing and going quite fast but can not feel the pressure needed to do a manoeuvre or jump. So it tells me I was just working on apparent wind and the moment you go into neutral to do a manoeuvre, the board slows down and the pressure drops.

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A windsurf sail is soft and very flexible so does not work exactly like a wing but similar.

A sail has an optimum angle to the wind for it to create laminar flow, so drive. 1.) shows you do not need to close the sail so much to create this. In a. it is the true wind and b. your apparent wind as you move forwards. The wind and your speed is always fluctuating, so your sail is always moving slightly. I call this floating or breathing. The rig will feel light and stable.

Looking at 2.) you will see that if you do not alter the angle of the sail as you accelerate, the airflow is interrupted and the drive will reduce. The front of the sail will loose power. If you sail with the correct size for the wholes, you will most likely sail with the sail open a lot of the time, so inefficiently. The sail will tend to be back handed or even worse you have to push with your front hand as the front of the sail gets back winded.

A windsurf sail needs pressure on the windward side of the sail to make it form it’s profile/shape. As you start to get planing you will need to close the sail a little as in 3.a). The back of the sail will be stalling a little, so it is important to get laminar flow as soon as possible as in 3.b. A common mistake is to close the sail and lock it down, which can cause the back of the sail to stall again, creating pull but little drive.

A slalom / speed sail has a more fixed profile with a large wing section in the lower luff section but is still relatively soft as it needs to rotate to sail in both directions.

SPEED-FG-1-ANTOINE-WH

https://www.youtube.com/watch?v=t15LZ1Er-a8   Antoine Albeau

You can see even at this high speed it looks effortless………….. Well!! He is breaking the speed record.         Balance.

Now we look at the body.

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The optimum hight for the boom seams to be shoulder hight when stood up by the mast as in 1.) this means that when not planing the boom may seam to be high. 2.a) shows a comfortable suspension, it is amazing how little pressure you need in the sail to achieve this position. 2.b) is when you need to use the weight of the rig. So in light wind you will be oscillating between (a) and (b), it is important to try not to go past vertical.

3.a) shows the position up by the mast. As you move back down the board, the rig will need to be raked further back and this brings the boom lower as in 3.b). You can still keep the comfortable stance. But in (c.) you can see that if the boom is to low you will be tempted into a different stance. (This position is Ok if you are totally overpowered.)

Booms are all different widths and you can see in 4.) that it can make a large difference.

Our aim is to keep the mast vertical and use the body as a lever against the power of the rig. Ok there are some times that we must use strength, if you are using this all the time, your sessions are not going to be very long.

BODY-1-b-WH

When your body is straight it is using the least amount of energy, so the most efficient stance will be this. You are using your body purely as a counter balance. People are always asking, how long should the harness lines be? You can see that it depends on where the hook is, so where the harness is. It will also depend on the body angle you are using.

The most important thing is that you use your harness 100%. Your arms are just for controlling the rig but can give extra leverage when needed. The power is created through the hips. The more power you are holding / creating, the further the hips will go outboard. Notice the legs do not bend.

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 So 1.1) is a low power position / light winds. The lines will be shorter and the body in line. The extra pressure you can put through the arms is not so much. 1.2) the hips are further out, creating a slight bend in the body. Here you can drive harder with the hips. Obviously the lines need to be a bit longer. 1.3) This is more the position of a speed / slalom sailor so I have shown it on the outside of the board and wider boom. They are using big sails and sailing overpowered, the hips need to be out as far as possible to get the leverage. So for normal sailing if you are overpowered lower the boom and lengthen the lines and you will be able to control it. Diagram 2.) shows that if you have your arms apart they normally will bend and you will be closer to the boom.

You will notice the Pros all sail with very long lines.

https://www.youtube.com/watch?v=sfgZP_UphfI              Hugo de Sousa

http://windsurfmoves.com/p/wsm-svbsa15      Steven Van Broeckhoven

Finally lets have a look at the board.

Every designer has his idea of how he would like the board to ride to get maximum speed. So the most important thing to keep in mind is let the board run. To often you fight the board to try and make it do what you want.

https://www.youtube.com/watch?v=uYih0xhJrrU  Slalom.

https://www.youtube.com/watch?v=ByraANIj7Ws  Gollito.

https://www.youtube.com/watch?v=bdWeeL3xOwU  Wave.

I have discussed this before in this link.

https://thewavehobbit.wordpress.com/windsurfing/the-basics-in-advanced-windsurfing/the-balance-of-the-neutral/

TONKY-SPEED-WH

If you do not have speed it is very hard to do the manoeuvres you wish to do. So remember speed is your friend.

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