Tom Slingsby, the Oracle Team USA tactician and sailing team manager, believes the defenders of the “Auld Mug” have made headway in their quest for faster speed in light-air conditions.

Oracle’s vulnerability in the lighter wind was laid bare for all to see during the opening four races of the America’s Cup Match presented by Louis Vuitton on the Great Sound last weekend.

Challengers Emirates Team New Zealand were unstoppable, winning all four races in the light and shifty breezes to jump out to a 3-0 advantage in the best-of-13 series.

Jimmy Spithill, the Oracle skipper, admitted afterwards that his team “wasn’t fast enough” and said the layoff period between races four and five would be “the most important five days of the campaign”.

During that period, Slingsby, an Olympic champion, said the team had found some speed in light breezes, which are expected to prevail when racing resumes today.

“We’ve definitely taken a step forward,” Slingsby said. “We’ll find out whether it’s enough of a jump on Saturday afternoon.

“It’s clear they [Team New Zealand] had an edge in speed, but we also did not sail to our potential.

“Tomorrow we will be faster and try to race smarter and, hopefully, that will make us an even or better boat.

“We’re looking forward to getting out there and competing again.”

Team New Zealand have kept close tabs on their rivals throughout the layoff period.

“They have been playing around with several different things with rudders, elevators and also their boards,” Murray Jones, the Team New Zealand performance coach, said.

“They have been doing a lot of work changing a few things closer to probably how we sail the boat and experimenting, so I would expect them to sort of lock in and get used to sailing the boat again in a slightly different configuration.

“They were in a situation where they had to make changes for sure; they were slightly slower than us. But I don’t expect them to look a different team.

“They have been sailing like this for months and years, really, so I can’t see them making any major changes this week.”

Two races are scheduled for today and tomorrow, beginning at 2.12pm each day.

First team to seven points wins the “Auld Mug”, regarded as the pinnacle of sailing.

Oracle are gunning for a third straight America’s Cup triumph and New Zealand a third overall — and first since 2000.