Hi Robert
Hamish has given I think comprehensive information about his adaption of boards. As everything in life, chaning one thing to the better will change an other to the worse besides for a boat in a given sice. By the way, I design boat a bit longer as yesterday. So when you had the plans you would see that there is an aoutside stringer at the areas between the dagger board. For a small catamaran as the ECO 5.5 I am strictly against having a board only at one side. I outlined way some letters ago. If the board is on the wrong side it helps to turn the boat over. I think from you was also the question about sail makers in Europe. I have no clue, or I buy where it is the cheapest at a given moment in the world. Or I make them myself.?
So in the end ?my advice have on each side a leeboard with some bungee arrangements for automatic dagger board kick up. The a-symmetrical daggerboards are quicker to build and are more effective.
Bernd
Bernd Kohler