a) they can put a laser ring gyro or MEMS 6-DOF sensor on the AC72 for AOA and a host of other variables (likely existed from day 1) b) multiple sensor technologies exist that give you height above water. c) all of it is pretty darn cheap, save a laser ring gyro which is unnecessary (not navigating from point A to point B 3000 miles away)
I've been thinking about this all week, it's really the only solution I can see making a notable speed gain in the short time frame they had to modify the boat. I'm not sure it's class legal, and I'm not sure I believe the report that it's true.
