Thanks so much -recall reading the paper --They concluded "Although she flew well, was very
controllable, and was spectacular to watch, Rocker could
not match the 20 knot plus speed of Alpha."

Rocker being the T foil cat design. Alpha entually winning the C Class cup.

What we are seeing in the Am Cup are radius U L or V shaped foils. The radius boards provide lateral resistance to track to windward and lift downwind at higher speed and powered up wingsail. The cup cats control the angle of attack of the foils for and aft with hydrolics for foiling platform stability though occationally falling off the foils during mark roundings.

Seems the L or V shape foil approach enabled solutions the T foil approach could not achieve

Perhaps some experimentation is warrented with self adjusting angled foils called surface piecing foils --the higher drag comparatively of this type might be offset by the potential abilty to foil upwind --the angled foils providing sufficient lateral resistance--It might be a matter of geting the ideal balance of angle -area-and lift vs drag.