I replied in the Mallacoota thread and then saw this one.

Smaller is faster given suitable water and wind conditions. There is a optimal size for all conditions, and it decreases as the wind increases.. But that does not mean that some talented individuals, (and usually of above average stature) have not got the ability to do quite fast speeds on bigger boards anyway. Especially in less than ideal conditions where a bigger board or sail my be a big
tactical advantage, despite not being optimum on the speed run in that one good gust. Examples abound.
You had hit on it already Piv: In highly variable conditions.

The fastest board for me @ 72Kg, in winds over the mid to high 20's is my 40cm/60L CA40. But for someone over 90-100 Kg it is probably considerably wider and larger, maybe 50-55cm and 85-95L?
But I didn't see any boards that big at Luderitz, even for the very big guys! I think AA's record board is 37 or 38cm
And Lena was on a 36cm sliver!

I think I need that Mistral 37 to challenge my PB!