The form of the nose is influencing the fin performance to quite an extent. A big nose radius (a blunt nose) allows a bigger angle of attack and produces more lift. The speed potential is reduced.
A small nose radius is causing opposite effects. There is an increased demand on the technical standard of the sailor to get good all-round properties. If the standard of the sailor is a high one, a small radius and a flat profile may become an advantage.
There is a correlation between nose radius, maximum thickness, thickness distribution and the width of the fin which was confirmed by practical tests but still is a topic in discussion. One thing can be said for sure: there has to be a certain radius of the leading edge, otherwise in sideways drift a constant flow around the fin cannot be developed. In addition a sharp leading edge would be dangerous.