General conscencus amongst us is that they have minimal effect but quite a few sailors insist the wind is not as steady as it used to be.
I think the farms are normally arranged perpendicular to the prevailing winds to reduce any effect they might have on one and other but obviuosly there are times when they are downwind.
Could be that quite close to them the wind is actually stronger at ground level (under neath lowest height of bades) ?? So sailing near them may well be
Not sure of power ratings of our turbines but they must take out energy from wind ; wether these amounts removed are significant to total amount passing by I`m not sure.