Xavier,

the rule as discussed is sail area=sail + half mast or sleeve as the case may be. Should probably include a term for luff length ie. for sails with a luff rope area = sail area + half mast circumference x luff length or half of the actual sleeve area. Aside from that at this stage you can have any form you want. For example last I heard the Vudus will have a boomless deck sweeper.

Also we originally discussed a max mast length of 6m (which IIRC is what Wouter is planning. I reduced it to 5.8m on the DS12 as I was happy with the basic plan form that this produced and it also made the boat both more stable and easier to right.