Simmer was reacting to the radical concept design of a 75-foot foiling monohull to replace catamarans revealed by holders Emirates Team New Zealand for the 36th America's Cup in 2021.
"It's not a boat like any of us has sailed before," the four-times America's Cup winner told Reuters by telephone from British challenger Land Rover BAR's headquarters in Portsmouth on the south coast of England.
The veteran of 10 America's Cup campaigns, who first won the event as navigator on Australia II during its historic victory over America in 1983, likened the hydrofoil design to the tiny Moth dinghy which has become a favourite for top-level sailors looking to hone their foiling skills.
"Going from 11 feet to 75 feet is one hell of a challenge," Simmer said, adding that the British team led by Ben Ainslie would use dynamic modelling and scale models to work out the best way of building an AC75 boat within the design parameters.
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"It's early days, but our modelling is indicating that these boats are capable of 50 knots," Simmer said, adding that achieving such speeds would depend on how efficient design teams could make the set-up of the towering sails used to power them.
New Zealand and Luna Rossa, the Italian team backed by Prada boss Patrizio Bertelli who are the challenger of record, were looking at a "semi-soft wing" mainsail but were planning more testing before making a final decision, Simmer said.
Teams such as Land Rover BAR will have to figure out the best way of building a boat of this size without a traditional keel for stability but using instead two one-tonne foils which will move up and down, lifting the hull to "fly" over the water.
"When the hull is in the water with both foils down you will have a reasonable amount of stability...(but) the boat will be quite unstable at low speed," Simmer said.
TECHNOLOGICAL CHALLENGES
Simmer, who previously ran Larry Ellison's Oracle Team USA, said he had thought about giving up after their loss to New Zealand in June, but decided instead to join Ainslie and to wage an 11th campaign for international sport's oldest trophy.
"I love the challenge, I love being part of the team and working with such a great group of people. That's why I did it," Simmer said of his move to Land Rover BAR, whose campaign to bring the cup back to Britain Ainslie expects to cost some 100 million pounds.
Simmer is confident that his and other teams will be able to overcome the technological challenges in building a boat that will appear to defy gravity by flying over the waves.
He will be relying on Ainslie, the most successful Olympic sailor ever, and his crew to master the skills needed to control the new high-tech machines.
"Ultimately it will be a hell of challenge to sail a boat like this ... We'll get there, it's definitely do-able."
(Editing by Clare Fallon)
