While I am not a naval architect by any means I have raced sail cats back in the day... seems to me you would need some method to provide a counter force to the sail pushing you to leeward. Didn't notice a centerboard accomodation?

Most sailboats have a centerboard but hobie cats used an asymetrical hull to provide 'lift'. The rudders could be used to counter the tendency to slide down wind but its not very effective.

One thing you will want to have extremely adjustable is mast rake.

Do you have a model boat to get rough dimensions for the mast, beam and centerboard placements?

i dont have a model, i was planning on basing the dimensions for the beam and trampoline placement on a hobie cats specs. but for the sail i was planning on using a 13 square meter windsurf sail .

and a center board is in the plan, just not there yet

Hi rdoran66,

I don't know much about boat building, but I'm pretty sure you'll need to reinforce the places where the cross-beams meet the hull. Maybe double up the frame? Also, you'll need some kind of standing rigging, which means chainplates (also reinforced). Catamarans have to deal with a lot of stresses in multiple directions. 

Thanks for the pictures! I'm eager to see the outcome!

Good luck!

Jean.

An idea for the centerboard... suppose you had a water tight compartment in each hull just large enough for folding skegs. You could bungee the skegs so they were held in the down position with tension but if you beach it they would fold up into the hull.

 Also, I am thinking a windsurf sail will not produce enough power for you. A catamaran is about speed, after all :-)

Potentially, you could have a mast in each hull with two sails? Sort of like a double masted ketch but side by side.

Cool idea JayC. I think they call that a "bi-plane" rig. That is, a free standing mast in each hull.