When my state farm agent didn't want to insure my boat, I asked him a simple question that led him to go research the policy deeper.

I said ... "Would you not insure a farmer's tractor if he told you that he was going to use it to plow his fields? You don't buy a high performance catamaran if you're not going to race it. The whole purpose it exists is to race."

Which, is not entirely true, but it planted the seed of disbelief in his head that caused him to actually, you know, read the policy.

If worse comes to worst, you can go with the US Sailing insurance. I believe they insure F18's of all flavors.