Karl

I'd agree with your observation about Vipers and the F18's. They seem about the same pace especially sailed two up. The one up F16's tend to slow up relatively when there is a bit of breeze on - not enough hands to do all the jobs in the corners! The F18's seem to have an advantage also in big breeze and waves. A's tend to beat them to windward until they are two on the wire then they aren't far away.
I don't think there were any MkIV's in the last A Worlds. You're probably thinking of Jack Benson who came third on a Flyer I. He's a great young sailor brought up on the light winds of Darwin - just like Italy. He has really worked hard the last two years attending all the big events in Aus - his boat is is in Brisbane now ready for the Cat Challenge in November and Aus Nationals in January. The Flyer I is not at all like the MkIV - it was the first of the boats with the high bouyancy keel line boats - so called wave piercing designs. The MKIV still has quite a vee in the under water shape. A great club boat still, but not likely to win a Worlds.