Rivals Oracle Team USA and Artemis Racing took full advantage of sailing in the Great Sound last month around the same time when all racing in the 35th America’s Cup will be held in 2017.

The two teams were able to gather vital weather data for their design packages while sparring in their wing-sail, foiling AC45 development catamarans.

Tom Slingsby, the Oracle tactician/helmsman, described the conditions as “challenging” and “incredibly tactical”.

“Here we have to learn light winds, strong winds and it’s a challenge for the sailors and the way it should be really having to master all conditions,” he said.

“We were out there racing against Artemis and it was about 18 knots and we were in huge tacking duels upwind. We thought we might have had an edge in tacking and thought they might have been a little bit quicker, so we were trying to drag them into tacking duels and it was incredibly tactical.”

Nathan Outteridge, the Artemis Racing helmsman, added: “San Francisco is very different than sailing here in Bermuda so we wanted to come here and check out what it is like, and being here through May and June and learning the weather condition has been pretty valuable.”

Oracle were the first to launch their 45ft foiler in early May and were soon followed by Artemis who have given the America’s Cup defender a good run for their money in training.

“They are beating us more than we are beating them,” Slingsby said. “But, as frustrating as it is for our sailors, it’s good for the overall programme to get beaten by other teams because you learn so much more when you are losing then when you are winning. It’s tough for our egos, but it’s good for the long term.”

Outteridge, who is an Olympic gold medallist and world champion, said both teams have been learning from each other during practise races in the Great Sound.

“We watch them tack and video them tack and they do the same on us and then the next day we come out and kind of swap,” he added. “We’re doing what they we were doing and they are doing what we were doing and it’s quite fun like that.

“These boats are old 45s we have modified to be more like what the Cup boats are going to be, so it’s been a bit of a design process for both teams and we have sorted of ended up with very similar packages. We’ve got two boats that go roughly the same speed.”