I've been working on a couple of proa models... one is your basic long skinny boxy canoe form... the other is an asymmetrical shape that is designed to eliminate the need for a centerboard. Still trying to decide which route I would go for in a full size version. The outrigger hull would be pretty much the same in either version. Still trying to decide too on whether to use big ass bamboo for the connectives or something purpose built. The bamboo version would probably need to be glass and epoxy reinforced both for strength and longevity. So it kind of defeats the purpose of using it to start with... which is you would not have to fabricate it. But I have harvested some and we'll have to see which method wins out. I found a good deal on some used sails that were meant for the head sail on a regular sailboat. They are quite large... I cut some bamboo that would have been long enough to use as spars for one of them had I not shortened them before hauling them home. My trailer was only about 20 ft so quite a bit hanging off the end. They were 35 feet plus before I hacked them... kicking myself a bit now.
The pond test was mostly to see how the two hulls sit in relation to one another. The mount on the smaller hull was temporary. I think I'd want a little more displacement in the smaller hull. It's sitting pretty deep in the water.
Still working on the asymmetrical hull. I don't think it would float upright without an outrigger.