America's Cup: AC75 class 'too extreme' says Luna Rossa team principal Patrizio Bertelli

The AC75 foiling monohull is expected to reach high speeds. Image / supplied

With preparations well underway for the 2021 America's Cup, the 75ft monohull design set to be sailed in the regatta is again the subject of scrutiny.

Luna Rossa Prada Pirelli team principal Patrizio Bertelli has hit out at the design for being "too difficult, too extreme."

Speaking to Italian publication La Stampa, Bertelli revealed he was one of those who wanted the 2021 edition to be raced on monohulls, but was hoping Team New Zealand would come up with a less complex model to what was presented when the class rule was announced.

"I had suggested to the Kiwis to choose a less extreme boat than this one," he told La Stampa. "A sort of modern VOR60 (the boat of the former Volvo Ocean Race) on which to develop two rudders with foils. Instead, they [Team New Zealand/Royal New Zealand Yacht Squadron] wanted a hyper-technological solution, they insisted.

"The electronic part is especially complicated. We have been working on it for two years."

Helmsman Francesco Bruni had similar thoughts on the matter. He told La Stampa the AC75 was a harder vessel to sail than the catamarans.

"The [catamarans] rose on the water resting on four points, didn't they? The two rudders and the two dinghies. These rest only on three, the two rudders and the arm-foil, with the other arm weighing one ton and protruding from the hull for 5 meters," he told La Stampa.

"Do you understand? It's a question of balance. You have to come up with a new way to navigate and it's not easy. We saw it after a year on the simulator and with the first outings at sea with the prototype. It's a question of speed and balance, you have to find the magic."

The 75-foot foiling monohulls were expected to reach speeds as high as 40 or 50 knots. In February, America's Cup Events' Peter Thomas said the size and speed of the yachts was going to be incredible, but for that to happen they needed to ensure all systems worked as planned.

"Part of putting the system together is it's got to function and it's got to be reliable," he said. "You can imagine with these big yachts racing around at these high speeds, when they go for a manoeuvre, the system has to work.

"There are over 400 components, and we have to make sure every time they hit the button it drops and if they want to raise it, it raises."