AC72 design - controlling the foils
The AC72 design rule prohibits (in paragraphs 8.6 and 9.6) movable control surfaces on daggerboards and rudders. So, how can you "fly" - hydrofoil - with the hull lifted out of the water? Isn't that like trying to fly an airplane with no flaps, ailerons or elevators? Yep. So the clever AC72 design teams have figured out how to adjust the angle of attack by moving the entire daggerboard fore and aft, inboard and outboard. This is some of the most secret stuff and gives us America's Cup fanatics lots of grist for our speculation mills.