I'm not too surprised that low aspect centreboards seemed to work ok. The Mosquitos in Australia have moved to smaller and smaller centreboards over the last 10 years. They are narrower (fore and aft) as well as shorter. Last season I started using them raised 200mm upwind and all the way down downwind (to help balance the spinnaker). This puts more load on the rudders upwind, but sailing cat rigged it really seemed to work (I couldn't say for sloop rig).

What is the reasoning behind the huge long centreboards on the F18s? It was a worry for the F18s at Forster because there are shallows in that lake. Seems a bit of a handicap really.

Tim