Testing Sails.

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I love it.

When ever I can, I like to test sails to find out what they are like, or find out how they have changed, or in this case testing a prototype sail for Xtreme Sails. This is the Zero, there 5 batten wave sail. I use very small sails all the time, so they gave me the 3.7m.


All manufacturers will give you optimum rigging measurements from the designer and test team. In this case they just said, go and play with the sail and tell us what you find.


When ever I test a sail, I have a setting I like to start with. I like relatively flat sails, 4th and 5th batten I like a flat profile. I also like tension in the clew. You can see the sail looks very flat.


Now loading up the mast, shows that the shape comes into the sail. These sails are very powerful. What surprised me was how little wind I needed to use this sail.

You will also notice the harness lines are quite far back, this is more like the 4 batten sail setup and I like the position. The sails are very fast.


Here the sail is in the light wind setting. Personally I do not use this as I find the optimum setting for a sail and only use that setting but for testing I must find all settings. With this setting, the sail is very powerful and would suit heavy people.




You can see that my adjustments are only up to 1 or 2 cm. Many companies state this on the sails +/- 1 cm.

‘A’, is the strong wind setting’ B’, light wind.

So now I will show what I am looking for, when I adjust.



When doing the Down haul I am not looking at the loose leach but the second batten from the top. ( I must admit, this is more to do with a 5 batten sail, 4 batten I look for the same effect at that part of the sail. The second batten on a 4 batten sail is much further down.)

I pull the down haul until that batten is pulled away from the mast and is flat, as in ‘A’. This gives me my maximum downhaul needed. I will then let off a little down haul, until there is a little shaping there, as in ‘B’. this gives my light wind set.

I will then give a bit of out haul until I have a bit of tension in the clew.



Now I load the mast to check for collapse. The high wind set there will be no problem but in ‘B’, I am looking at the window panel. If it begins to collapse I have let off to much down haul.

It is also important to check the clew tension. If there is not enough tension the sail will touch the boom, so you will need more outhaul.



You can see in ‘B’, I am right on the limit for minimum outhaul.

So these are my 2 settings. I will then go on the water to find MY optimum setting. The down haul is very close to the settings in ‘A’ and I will just adjust the out haul by 1 cm, so not as loose as ‘B’.

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On the water we are looking for how the sail is moving, checking the twist and how it powers up and de-powers.

Is the center of effort stable? If it is moving around a bit, it may mean you do not have enough out haul.

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Doing maneuvers where you are back to sail helps me to see the other side of the sail and gives me more feedback.

Then it is back to the beach, make adjustments again and out onto the water.

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Finally it is back to see the designer and give him your findings. Remember you are not a designer, so suggesting changes is not always useful. Just tell him what you felt and how the sail behaved when you changed the settings.

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