Shimmering in the heat, the Barcelona cityscape was the perfect backdrop for a perfect day on the water for three America’s Cup teams all pushing hard to find the ‘edges’ and eke performance. Two AC75’s and two AC40’s gave the beachgoers a hell of a spectacle with the Swiss, New Zealand and American teams close to the shore showing devastating speed and power as the Garbi thermal from the south delivered flat water and 10-14 knots of building and fading breeze.

Andrew Campbell, Flight Controller extraordinaire for American Magic summed up a productive session saying: “I think every team feels confident in those conditions, I mean it's about as easy as it gets in terms of handling, the sails aren't super loaded, and the boats are going so fast and they're so light that they're really easy to sail and fun you know. I think conditions like that when they are easy, it’s time to push the boats really hard and find where the edges are and find where the sensitivities are.”

Docking out into the afternoon sea-breeze build, American Magic had a highly controlled day of two boat foil and aero testing, lining up America and Magic on straight runs on starboard tack to evaluate their newly declared fourth iteration of Foil Wing 03 on America against Magic’s Foil Wing 01. It was a productive four hour session but the team were really looking for windier conditions to push into the testing more with Andrew commenting: “We were trying to get some different conditions today but it turned out today was really similar to yesterday and we were really hoping that we would be able to stretch it out and get some breezier conditions but that kind of Barcelona sea-breeze stayed mellow and we had a lot of 12 to 14 it was about as nice a day of sailing you could ever ask for but we were looking for a little more.”

After one stint, as we have seen on previous days, Andrew Campbell was called upon to climb out onto the raised port foil arm to check the wing and apply what looked like a lubricant product along the outer wing. Talking about it afterwards, he commented: “It's one of my jobs to go out and make sure everything is kind of working the way we expect it to and there's little pieces and parts that we want to make sure are still functioning right after a day and if we don't have time to come in and service them, then we have to give a check on the water. So that's one of my gigs to go out there and hang and look it over and make sure it's clean and ready to go again, and that's all, just making sure it's up to spec.”

From the recon shots from the dock the new port wing looks to have an interesting foil flap set-up with the outer flap extending beyond the centreline of the bulb and an extended run-off straight off the bulb. Upwind Tom Slingsby and Lucas Calabrese brought on the windward heel/bow down style that they favour and with the settings matched on both boats, the leeway reduction was marked and the gain in height was pronounced. A solid day to conclude the week of testing before the team switch back to one design mode for the upcoming Preliminary Regatta in Vilanova i La Geltrú from the 14-17th September.

Whilst American Magic two-boat tested, Alinghi Red Bull Racing and Emirates Team New Zealand launched their AC75s for a mighty display of power and technique along the beachfront. The Kiwis looked totally controlled in Te Rehutai, with the Flight Controllers maintaining their super-low ride height and windward heel that has the effect of dipping the windward raised foil tips in the water. An interesting observation was made by the on-water recon team who noted: “much less water spray and turbulence coming out from the rudder, possibly related to a less aggressive rudder rake.” And it’s clear that the Kiwis are trying all manner of subtle set-up changes to eke speed from Te Rehutai.

Once on the virtual racecourse and doing laps, Pete Burling and Nathan Outteridge pushed hard through the manoeuvres, calling for a huge number of tacks and gybes from the power unit whilst they concentrated on low exits downwind and very tight tacks upwind. Hugely impressive as always, the Kiwis clocked in a total of 76 tacks and gybes with a 93% success rate foil-to-foil. Speaking afterwards Pete Burling summed up the day saying: “It was really nice to get the big boat out, Te Rehutai, and we ticked off a few things that have been kind of outstanding questions, and then did a few race laps at the end. It was really productive for us…just playing around with some different setups and making sure stuff lines up with what we have in the tools. Really happy with how things are going but yeah always trying to learn and improve so that's what we were doing today.”

Pete will be eyeing a good result in the Preliminary Regatta in Vilanova i La Geltrú and it’s clear that the focus is now starting to shift towards preparations for that: “It’s definitely coming around pretty quick, Vilanova’s a little over two-and-a-half weeks now so it's yeah really exciting that there will be racing in the not too distant future and you know as a group I think we've taken on a lot to get ready for this event, you know a lot of noise and things going on, but for the sailing team it's really about making sure we do everything we can to get ready in the AC40 and we haven't actually had a 40 in the venue very long, so it's going to be a busy few weeks ahead making sure we build up to it well.”

Meanwhile Alinghi Red Bull Racing brought the much-modified ‘BoatZero’ out for the afternoon and continued their impressive week of consistent training with the AC75 looking comfortable as the breeze built late in the afternoon. Ride heights were interesting with a super-high mode downwind at times with the foils only just immersed but looking totally under control with Bryan Mettraux and Yves Detrey doing a magnificent control and trim job whilst Arnaud Psarofaghis and Maxime Bachelin drove harder and harder – these two are forming a powerful and productive helming partnership and their transitions look smooth and controlled.

Upwind, the team are really dialling into the low-riding style that all the teams favour with a modicum of windward heel and once BoatZero was on a pre-laid course, their helming was accurate and impressive with ‘JK’ moves around the leeward gate, fast round ups on a single board and smooth bear-aways at the top gate. In total, the Swiss put in a mighty 81 tacks and gybes with the recon team noting an uptick of some 15% on previous sessions in successful foil-to-foil gybes. Little by little, the team on the most vertical of learning curves is closing the gap to the teams that competed in AC36 – Vilanova will tell us exactly where Alinghi Red Bull Racing are at in a few weeks’ time.