First of all thanks for the clues they were helpfull indeed.
I had the opportunity to sail my iS105 for the first time this past week.
Conditions called for 6.5 and 8.5 for my size ( 66Kg, 1.7m ).
However I sailed with the wrong sail each time. I mean when it was 8.5 I was on 6.5 and vice versa.
However I have to say that this is another excelent product from *B. Congratulations to all!
Sailing iS105 with 8.5 Severne OD rigged for high winds is definitely OK. I used HS 42cm stock fin on both ocasions. II found that it sailed fairly well upwind and had no spinouts though I never pushed to check the limit.
I was overpowered and get tired relatively soon. But other than that tacking was the only issue with such sail size. I was surprized to notice that it planes early for its size and IMHO is less demanding to sail and jybe c/w HS133. It was easily under control and its real speed is not easily noticed because of that.
It is a very different animal to HS and although I love my HS133 I definitely will change it for an iS133
I'm pretty happy and can't wait to sail it with the right sail next time.
Thanks a lot guys.