There was no counting of chickens going on at the Ineos Britannia base in Barcelona on Thursday. Despite being on the verge of a first America’s Cup match in 60 years – 6-4 up in what has been an epic, first-to-seven challenger series final against Luna Rossa – it was business as usual in Ben Ainslie’s team.

Data analysts from partners Mercedes F1 sat glued to computer screens, boat-builders scurried about preparing ‘Rita’ for battle, sailors attended a light-wind primer ahead of what is expected to be extremely light conditions on Friday. No one went sailing.

“It wasn’t worth it today,” explained Ainslie over a lunch of lean chicken and salad in the staff canteen. “The wind direction was unusual and we decided it would have been of limited use. Better to give everyone a rest before we get back to it tomorrow.”

Luna Rossa decided the same.

‘We’re not there yet’

While on the surface everything appeared normal, it was impossible not to detect the heightened tension in the building.

Everyone is aware of what is at stake here. They can sense the interest building back at home. The America’s Cup is not mainstream news yet, but it could be about to be. The presence of a BBC production team in the foyer was just one clue that Britain is beginning to wake up to the fact that Ainslie’s team are on the cusp of something historic.

No British challenger has ever won the America’s Cup. This is the 23rd attempt since 1851. It is the oldest international trophy in sport, it was born in UK waters, and this time it really could be coming home.

Not that Ainslie would contemplate it. “We’re not there yet,” he insisted. “There’s no point even thinking beyond the next two days. We have to get to seven wins first. We have to take it one race at a time.”

He is right, of course. Ainsle knows better than anyone how quickly leads can evaporate in this game. He was part of the greatest comeback in the history of the Cup, in San Francisco in 2013, when he helped Oracle Team USA to overturn an 8-1 deficit against New Zealand and win 9-8.

Luna Rossa could easily bounce back on Friday. Jimmy Spithill’s team have already done so countless times in this series, levelling things up at 2-2, 3-3 and 4-4 before Ineos finally broke the deadlock and won two straight races on Wednesday.

These two teams are so evenly matched. Even if there is enough breeze to get racing on Friday –and there is no certainty of that – it could well be a light-wind lottery, with both boats desperately trying to stay up on their foils as they tiptoe around the course.

“It is certainly going to be a reset for both teams, to try to get locked into those lighter conditions,” Ainslie said of the anticipated change from the sort of top-end conditions we experienced in the first part of the week, which featured 20-plus knot breezes and messy sea states.

“The positive thing is we went really well against Luna Rossa last Saturday in similar light breezes, albeit the race got timed out [Britain were leading on the final downwind leg when they hit the 45-minute race limit]. We’re not afraid of that.”

‘I don’t know whether Jim will continue’

Ainslie may not be prepared to look ahead to a possible final, but he is sure of one thing: Britain will compete at the next Cup. Either as the defender or as a challenger again. Regardless of what happens in the next two days, regardless of whether Sir Jim Ratcliffe and Ineos continue to back the team, and regardless of whether he is on the helm or not.

“I haven’t even thought about that,” the 47 year-old insisted of whether he would continue to take the wheel beyond the age of 50. “And I honestly don’t know whether Jim will continue. He has got a lot on with his different sports teams. He has been a fantastic backer of the team and of course we hope he does.

“But regardless, this team is going to continue, whether we get the job done this time or not.

“I’m so, so proud of everyone; the way we have worked together in this campaign. I’m sure you’ll have noticed during your time out here what a positive energy there is around the base. We’ve got to keep hold of that.

“In an ideal world, we’d continue with Mercedes. But if for whatever reason we can’t, we are in a much stronger position than we were last time, when we basically stopped for six months and then started again.”

Such considerations are for another day. For now, the focus is simply on securing the win which would guarantee Britain a first America’s Cup match in over half a century. What would it mean for the sport? For sailing in Britain? Ainslie shakes his head. “I don’t know. It has been such a long journey. It is so so hard.

“Even this Louis Vuitton Cup final with Luna Rossa... you get these moments in the America’s Cup, that 2013 comeback in San Francisco being one of them, there are probably half a dozen classic moments in America’s Cup history, and this Louis Vuitton Cup final is probably not far off being one of those moments.

“It would be amazing if it did catch the imagination. I feel pretty insulated from all that out here. I’m not exactly trawling through social media. But you can sense the interest growing that is for sure - more interview requests, more messages from friends and family. And that’s great. We want the country to get behind the team.

“But as I say, we have to get that win first. Nothing else matters. Luna Rossa have been such tough opponents. They have forced us to push the boundaries of what our boat and crew are capable of. And I know there is more to come.

“One thing is for sure, whoever comes through this is going to be seriously sharp for the final.”