America’s Cup teams crack the foiling tack
America’s Cup teams, now adept at foiling all the way through gybes, are beginning to perfect the foiling tack. The first to claim the feat was Japanese team Softbank Japan, which revealed it in August, despite first accomplishing this back in April.
The advance is a significant performance increase. During the last America’s Cup, teams could lose over 100m during each tack as they dropped off their foils and regained enough speed to fly again. Foiling all the way through reduces that deficit.
The foiling tack itself is not a new manoeuvre and is something that has been done by Moth sailors for some years. Those sailors have found that practicing the techniques needed for foiling tacks can improve performance even if the manoeuvre fails and the boat drops down during tacks.
“We cracked the foiling tack in April of this year and have made consistent gains in how we approach and refine the manoeuvre since,” says Softbank spokesman Matt Knighton. “The foiling tack, once perfected and executed well, has the potential to open up the tactical game allowing the team to tack more quickly to maximise wind shifts, play certain sides of the course, and create advantages in boat-on-boat situations.”
But they are not the only team to have worked out how to foil all the way round the course. “You won’t think of it in terms of gains,” comments Oracle Team USA tactician and sailing team manager Tom Slingsby. “You have to think of it in terms of losses [if you can’t do it].”
Oracle Team USA also says it cracked the foiling tack in April, and can now do it without the power-assisted hydraulics on the test boat, which are not allowed in the America’s Cup boats being used next summer.
Performance will undergo a step change when the teams’ new AC50S are launched in late December and all the teams are expected to foil for a high percentage of the America’s Cup in Bermuda. Whereas the AC45F boats used for World Series events fly for around 40 per cent of a race, these new boats may eventually be able to foil for almost an entire race.
Above: New boats launched at Cannes Boat Show this year included the eye-popping new Lagoon Seventy7 catamaran