Johannes was kind enough to send me details of his various sailing designs, some of which are purely conceptual, others actually built and tested.
Amongst the clever designs that Johannes has come up was the a flying yacht. It could act either as a small yacht with a pair of canted sails or - if the need so arose - as a motorised ultralight floatplane!! Just the thing for that yachting trip to the lakes. Once you're bored with one lake, you could just fly over to the next! The sketch below is a side view of Johannes hypothetical craft, but you can see it in more detail here.
Another of Johannes' ideas was the "Morphe" a triangular monohull yacht that doesn't tack, but shunts like a proa. (Such a craft might be called a moa - being an abbreviation for monohull proa.)