What needs to be designed? Lots of things!
AC72 design - more cool stuff
How do you control... wing camber and twist? ...daggerboard height and angle of incidence? What hydraulics do you need? What instruments and electronics?
The fastest boat usually wins the America's Cup
Two hulls plus crossbeams. A bowsprit. No deck, just a trampoline made of netting. Hull shape is still important, of course, but with the AC72 catamaran, we have so much more to design to have a "platform" for our wing sail, foils and softsails.
"USA 17" capsized in mid-October. The most aerodynamic AC72. Much test and development work ahead. Relaunched in February with wheel steering. Much less twistiness ("racking"). Now foiling fast and stable.
Designed to foil, ETNZ is stable. Boat 1 had S-foils and a twisting forward wing element - impressive design! Now sailing their second boat, which launched early February. They tested C-shaped boards in March. On a ship to SF, will launch there in May.
"Big Red" was designed to skim, not to foil. She crashed 9 May 2013, taking the life of Andrew Simpson. A massive team effort got "Big Blue" on the water in time to race in the Louis Vuitton Cup semi-finals.
Luna Rossa bought New Zealand's design. Daggerboards are different. What else? The chrome finish on the wing and hulls gives a dramatic look. Like ETNZ, currently in transit to SF and will relaunch there in May.