I don't know why you say that the Kuka-Light has a little more than 1 ton of ballast. If we were talking about a mass market cruiser with the same characteristic of others a guess could be made, a relative one, but in what regards top racing boats that is hard to do. Regarding Open an 60's or a class 40 the box rule implies very similar ballasts to each boat but this one is truly an Open boat, following no rule. They don't give the ballast an that can go from 30% to 60%.Probably it is not by accident that they don't disclose the ballast.
Yes - that was an guess and looking at the bulb in all the images available, i do not see that it weighs in access of say 50 % of displacement...
Regarding the comparison with a DIDI 40, you are not talking about boats with the same dimensions. The Kuka light is not only bigger as much more beamier: more about 79cm in length and more 120cm in beam.
What are you talking about?
The didi 40cr is just 10 cm shorter, has less beam but more freeboard and superstructure...
Comparing with a boat with the same type of hull and beam but smaller, a 40 class racer, for instance a racing Pogo 40 class (s2), the difference is huge: the Pogo with less 62 cm in length and less 10 cm on beam weights more 30% and that's huge considering the Pogo is a smaller boat.
Yes, a 42ft sailboat with a 4.6m beam weighting only 3200 kg is an extraordinarily light boat. Consider for instance that a A35 weights 4450kg and the Elan 320 weights 3690 kg and is one of the lightest boats in its class.
I am sorry, but you obviously did not get my point.
In plain: the keel construction and ballast alone weighs well over 2 t on the dixi...
That means that in race trim the whole hull plus hardware, rig and sails weighs less than 2 t... Can we agree on that?
I - and you - do not know, what the ballast ratio on the kuka is... But looking at the draft, one might think that the ballast will not exceed 40 % of didpl.
Why, you may ask?
Because "lightness" was standing in big letters on their design brief, as proclaimed on their webpage.
And the canting keel in combination with the big draft means a LOT of power from less weight.
And now go back to the homemade wooden boat and see that this nice little thing has so much weight in its keel and is still only 800 kg heavier... Strange hmmmm?