from what I've seen in the first test (you can read the condition and the trim in the post above) the board tends to stay very low on the water and it does need to push hard to keep the nose up and riding fast and free.
It means that the R17 doesn't fit this board fine when so light (as you earlier stated) althought I kept planning as never done before (I was on 10,7!).
I couldn't test the provided fin because it flipped in the box and no time to fix it.
Now I have a question about fin rake (R19).
I guess it is strictly correlated to sail model and brand to sailor weight and to mast base position. Am I right?
I mean,if we use a more forward raked fin we obtain a bigger power for pushing the tail and keep the nose up,we can use a smaller sail (in the a given wind) and going at the same angle and we can move a bit back the mast base.Does it correct? If yes, it will happen if the sailor is able to strong push the fin!
But, what about if it doesn't happen?! I guess that a fin like this will slow down the board. Please correct me if I wrong,I wish learn here.
So what's better for a med weight sailor good trained (around 80 kg) a +8 or a more "human" and faster +6 ?
But,what about board speed?
I think that in light wind a +8 is the way to go but what about when 15 kns or more?