LONDON (Reuters) - Artemis Racing have been flying in practise for the America's Cup, but the top speed of the team's foiling catamaran is a secret skipper Nathan Outteridge is not sharing.
"We don't want anyone to know how fast we are going," Outteridge told Reuters by telephone after another training session this week on Bermuda's Great Sound.
Racing to decide who will go head-to-head against defending champions Oracle Team USA for international sport's oldest trophy, known as the "Auld Mug", begins next week with the catamarans expected to hit speeds of up to 50 knots (92.6 km per hour).
Swedish team Artemis have shown good form, winning several practise races with the other challengers: Britain's Land Rover BAR, Groupama Team France, SoftBank Team Japan and Emirates Team New Zealand.
All the six-man crews are now working to get the most out of their 50-foot state-of-the-art America's Cup Class craft.
These extraordinary machines, the sailing equivalent of Formula One racing cars, are driven by a towering "wing sail" and controlled using hydraulic systems. Power is supplied by the crew "grinding" winches, or in the case of the New Zealand team by onboard cycles.
"The design phase is complete now, its about learning how to use your equipment and your tools properly," explained Outteridge, a 31-year-old who has won Olympic gold and silver medals for Australia in the 49er class with fellow Artemis crew member Iain Jensen.
"Racing has been really close between all the teams. We've done a really good job of all the little things around the course," Outteridge said.
But like other crews, Outteridge says there will be further improvements when the real racing starts on May 26 in a round robin series to eliminate one of the crews.
"We're working hard on optimising our boat," Outteridge said, adding that Artemis had focused on being as efficient as possible in using the energy generated by its "grinders".
These crew members have to sail the boat as well as deliver the horse power which controls the two foils that lift the hulls out of the water and allow the boat to "fly".
But with all the crews foiling fast, Outteridge says there is not much to choose between them going into next week's Louis Vuitton America's Cup qualifying races.
"Its all pretty even right now," he said. "Everyone is trying to learn about their performance. People are pushing the boat as fast as they can."
(Editing by Ed Osmond)