The basic dimensions appear to have been settled.

Using the democraphic data for children in the age range of 2 to 20 years of age, it has been confirmed that the F12 is indeed targeted towards :

-1- Girls and women from 12 years of age onwards (this includes adulthood)
-2- Boys from 12 to 16 years of age.

At 12 years of age there is no difference between boys and girls in weight, length or body strength or even the spread in either of these measurements; both are on average 40 kg and 1.50 mtr tall.

Girls and women never grow passed the average of 58 kg and 1.63 mtr of length. At 16 years of age boys reach on average a weight of 61 kg and length of 1.74 mtr. Obviously boys have grown a little taller but not heavier ! Adding mass happens mostly after 16 years of age. As such the age group of 12-16 can race eachother fairly as 0.1 mtr difference in length is obviously not significant on a 2.0 mtr wide boat.

The initial choice of designing the craft to be competitive from 40 to 65 kg was the right one. Of course the craft will carry alot more, but not in a "fair racing" sense. This is obvious as the cat much be able to carry at least 130 kg on one hull in a competitive manner. This requires both reserve bouyancy and of course a much heavier crew will put the luff hull back in the water. There is no reason why the craft can carry 2*130 kg = 260 kg in total before becoming uncontrollable. This corresponds to a combined crew weight of 195 kg or an 90 kg dad with two 52 kg kids (16 or younger).


But a far more important analysis will be righting. The required minimal righting force is determined as being 36 kgm. This means 36 kg handing off a 1 mtr long leverage. A "standard" crew of 12 years at 40 kg and 1.50 mtr length can generate 55 kgm of righting moment using the standard righting rope. This basically means that the standard crew is easily capable of righting the craft even in flat water and absolutely no wind.

The demographic data gives that 95 % of the children at 12 years of age weight at least 30 kg and are at least 1.37 mtr tall. These will be able to generate a rightig moment of 38 kgm which is just in excess of the required 36 kgm. So they too will be able to right the boat in flat water and no wind.

Naturally both waves and wind (if present) will help righting the boat, thus creating ample safety margin in conditions where safety is extra valued.

The F12 hull volume distribution will make the weight range of 40-65 kg competitive with 57 kg being optimal.

I should not be problematic to sail the F12 in a performant manner all the way up to 85 kg. The hull will have ample (reserve) volume for that because of the V-ed shape, alot of volume is found at the top.

It appears the currently designed setup will have no problems what so ever in withstanding the increased loads.

The design is a very elegant in the way the forces are all arranged such that they largely cancel one another out. For example the mast step loading is never going beyond 220 kg. Compare that to the 1500 kg's on for example a F16 or F18.

I'm quite pleased with the setup. Simple, cheap, performant and (de)rigged very quickly. Just like the laser-1 dinghy.

Wouter