Double handers and single handers :

The split in rating numbers between trapeze conditions group and a non-trapeze conditions group also allows us to correct the issue we have with rating singlehanders accurately with doublehanders.

There are many reasons why a singlehander generally performs better in the light stuff than in the strong stuff. We can't not compensate for them all for that would make the system to complex to use comfortably.

We can however take a few big important factors and correct for them thus arriving at much smaller offsets then before. Offsets that could well be to small to matter anymore when compared to sailor skill.

Beyond a doubt the most understood and arguably the largest factor in this is righting moment when compared to heeling moments. We have seen 18 squares clean up at Curacau when doublehanded while seeing singlehanded 18 sq. being left behind. There is one thing that is different between these boats. The same experiences are found in classes that sail their boat in two modes like the Taipan 4.9's. Lets use that experience.

The second biggest factor is control. It is just alot harder for a single hander to control and tune his boat in the heavy stuff than it is for doublehanders. Especially when flying a spinnaker solo as well. This factor can easily be included into the system by a weighting factor. That is in addition to the righting moment / heeling moment compensation.

There are certainly more factors as well but arguably the net gain that compensating for these can give are much reduced.

For arguments of simplicity I have decided to stick with these compensations and see if any others are still needed in the future. I do not expect that to happen. Certainly with these two compensations we will have sliced the offset to a fraction of what they were before.

Also the good part is that the Texel system contains all the data needed to implement these mods except width. For this reasons these mods are frightingly simple to implement. And also easy to maintain.

To calculate the righting moment / heeling moment ratio we use a simplied formula that contains known and noticeable offset with regard to reality. However it can easily be proven that these offsets are about the same for all designs and therefor the ratio's between designs are largely unaffected by that.

Example :

When taking a ratio of two numbers that are both 10 % of the mark and equal of sign than the ratio itself is only about 1% of the mark. Therefor you need not be very accurate in the base numbers as long as you can garantee that all offset are similar sized and have similar signs. That can be proven.

Proposed :

Heeling moment estimate = mainsail area * 1/2 * luff length main + jib area * 1/3 luff length main.

Righting moment estimate = weight boat * 1/2 * width boat + weight crew * (width boat + 1 mtr)

Notice how all input data is available in the Texel rating handicap system with the exception of the width.


In order to achieve aour accuracy we need to assign a reference design. For that we use the Formula 18 class.

This gives the F18 class a flat rating over the full spectrum of the wind speeds. Arguably a benefit in itself.

Wouter