The traditional angle of attack for sailing all the traditional Nacras, but especially the boardless ones, is to keep the leeward bow depressed as far as possible. This stands the mast back close to vertical despite the rake in the rig, and more importantly allows the narrow hull section forward to function somewhat like a centerboard. By "as much as possible", I mean that there should only be a few inches of bow above the water - more in wind, less to practically none in lighter air. If the deck is just awash in the puffs, you're perfect. Sail fast.