The Ballad Exchange

I am going to buy a new forsail. I now have a genoa I for furling (profurl). The sail is 27,4 kvm in size. Iam living in the west coast of norway in Bergen and the wind is often above 10 m/s. I am thinking that a smaler Genoa might be better. A Genoa II will be 24,2 kvm. Will the boat loose much spe...