Jimmy Spithill, the Oracle Team USA skipper, admits that the America’s Cup holders have their work cut out defending the oldest trophy in international sport in Bermuda in 2017.

“It’s a tough group of challengers and there’s no weak links for sure,” Spithill said. “When I look at the challengers it’s hard to say who’s the favourite because they tick all the boxes.

“They’ve got the talent, the designers and great boat builders, so we’re going to have our work cut out. These challengers are going to push us and whoever we come up against we’ve got to be ready to go because they are going to be tough.

“The fact is what got it done last time is not going to be enough, so we have to out think, out learn and out design and at the end out race and outsail these guys on the water.

“A lot of teams have learned lessons from last time and the technology really has spread out now throughout the teams.”

Oracle pulled off one of the greatest comebacks in the history of sport at the previous America’s Cup in San Francisco, overcoming an 8-1 deficit, to retain the “Auld Mug”.

Spithill said that he never doubted his team’s ability to pull off what seemed the unthinkable.

“It was obviously a big hole we had dug ourselves, but I always believed we could win,” he said. “I knew we had a great team, especially in the face of adversity.

“We had some tough challenges leading up to the racing, and it’s the tough times when you see the guys you want around you.

“When you’re winning everyone gets along. But when you’re having tough times that’s when you see the guys you want around you and so we were fortunate we had seen the guys in the fire and how they would react.”

Sir Ben Ainslie, who served as Oracle’s tactician, added: “It was a very tough period there, the first half of that finals, where we were really on the back foot and things weren’t looking good.

“As a team we just did an incredible job of developing the boat; working with the design team, making the changes and the boat builders’ initiating those changes overnight and just getting faster and faster. With that speed came more confidence and we sailed the boat better and made better decisions and it was a real thrill.”

Since that miracle on the water nearly two years ago, Spithill has parted company with some of his team-mates, among them Ainslie, who has formed his own British syndicate to challenge Oracle.

“Obviously Ben is gone and set up his own team and we’ve had a couple of our key grinders mix around with the other teams as well,” Spithill said. “But I think that’s awesome.

“I think it’s great that a lot of the sailors move around a bit between the campaigns. We do this because of the competition and because we are pushed.”

Ainslie, the greatest sailor in Olympic history, added: “I think if you go through all of the teams most of the individuals in the teams would have sailed with different individuals from other teams, so there’s quite a lot of rotation that goes on.

“Certainly I know a lot of the Artemis sailors very well, the Oracle team and I also sailed with team New Zealand for the Cup in 2007, so we know each other very well — and I think it works both ways.”