So...if you take the jib off a Nacra 5.2 it will be faster to A mark? I beg to differ. In fact, if you put a jib on an A-cat (with existing mainsail size) or an F17, etc. It will be faster. The reason the A's don't have a jib is that they are limited to sail area and have found that when restricted to a specific sail area, uni is the way to go since having it all in the main is more efficient than allotting some of that area for a jib. We're talking about two different things here.