“Wonder what Slieve thinks of this heresy?”

The only way to find out is to build it and sail it against another rig on an identical hull. In other words, you have all the problems of any experimenter.

For what it is worth, I feel that there would probably be a loss of performance when compared with a single split rig. I realise that there and many ways of increasing the lift of an airfoil, but most of them also increase the drag so that the lift/drag ratio falls, and therefore the windward performance is generally inferior. High performance gliders and modern passenger aeroplanes have long narrow wings, and without doubt a similar plan form would give a great lift drag performance on a boat, but we have to come down to what is practical.

Sails have a single surface and are built around a mast, so we have to do the best we can. The Bermudan boys have ended up with a single cambered sail in front of the mast and a deflecting sail behind, and generally find that an additional slot in the jib to make it a cutter has more drag. The split junk is an attempt to get a clear cambered single foil in front of the mast to get that important windward drive, and has the additional advantage of a better plan form than the triangular Bermudan set up. I feel that additional slot would increase the drag without an appreciable increase in lift, so would probably reduce the performance. It would also increase the production effort and cost.

But then, who am I to say?

Cheers, Slieve.