America´s Cup, conundrums to solve fot the British and Swiss

Flat water and a light sea-breeze gave INEOS Britannia a perfect blank canvas in Barcelona today to start digging into a conundrum that’s bothered the team since the arrival of their second AC40 for the two-boat race practise programme. What’s been spotted but not publicly acknowledged until today is the very slight speed differential that the new boat has over the AC40 that the team used in the two Preliminary Regattas in 2023.

Today, in marginal, lower-end test conditions, it was again ‘Boat B’ – or ‘Sienna’ – that held the upper hand with Sir Ben Ainslie and Giles Scott winning most of the pre-starts and speed tests over what appeared to be a marginally horsepower-struggling ‘Boat A’ with Dylan Fletcher-Scott and Ben Cornish driving.

The team were trialling a new triangular topped, low aspect J2 jib that they switched between boats with little difference spotted by the recon team and Ben acknowledged the speed issue in interview afterwards saying: “We are seeing a little bit of difference between the boats which is interesting from a one-design class perspective but yeah I think we need more time with this other headsail to figure out how it's going, we switched it between boats but it's hard to tell really...we’re trying to figure out what's causing that difference so we’re lining up the boats and making sure that everything is symmetric in terms of foil arm positions, rig and the systems on the boat to see if there's any differences there. For us it's really important to try and figure out what's making that difference because that will help us understand these boats in general.”

And Ben, also wryly commented: “I think we're seeing that ‘Boat B’ is just a click faster than ‘Boat A’ so yeah, I guess I wish we had ‘Boat B’ earlier in the year.” The mystery of the speed differential is something that this highly technical, data-driven team will, for sure, get to the bottom of and the results could be extremely important to their overall campaign.

Speaking about the new J2 headsail, Ben also made a very interesting comment that alluded to perhaps how prized the team might favour manoeuvrability over outright speed in the AC75 in a very tight Challenger Series, as he said: “It's also about the functionality of the sails as well. We know here in Barcelona that it's very variable conditions so you kind of want sails that are going to give you that variability, that ability to adapt to conditions, and mode changes, so there’s maybe more to it than just straight-line speed.” Interesting period for INEOS Britannia with plenty of learning going on all round and plenty for the Mercedes Applied Science analysts to dig into back at ‘Mission Control.’

Meanwhile over in Jeddah, Saudi Arabia, it was slightly lighter conditions for the Alinghi Red Bull Racing two-boat programme than the all-out extreme master-blasting of yesterday’s session. An opportunity therefore to concentrate on the aero packages with the two AC40’s featuring full LEQ12 sets of in-house designed and built sails and two very different mainsails trading high aspect ratio off against a low aspect ratio set-up to set forth a very interesting conundrum of their own making.

The sailmakers’ theory being that the higher aspect (long, thin and tapering to a finer head) might produce more outright speed in a straight-line, especially in higher wind-speeds, whereas the lower aspect (with greater volume towards the head) be both more stable and manoeuvrable in the key pre-start sequence, especially in lower wind-speeds. Choose the conditions, pick your style – that’s powerful.

Certainly, in the lighter airs of around 10 knots that greeted the sailors, it was all in favour of the lower aspect rigged ‘Black’ boat with Arnaud Psarofaghis and Jason Waterhouse steering initially but as the session went on and the afternoon breeze filled it became almost too close to tell with some desperately close racing. Nicolas Charbonnier and Maxime Bachelin paired up on the ‘Red’ boat and after assessing the characteristics of the new sail, built in confidence through the five hour session where some 145 manoeuvres were recorded (minimum) for the ‘Black’ boat – at a staggering 94% foil-to-foil ratio. That’s progress.

Once again, the race execution and technique of both Swiss boats was from another planet and as spectators we were treated to absolutely no-holds barred racing with desperately tight crosses, ducks, lee-bows, slam dunks, JKs, single board round ups, luffs – you name it, it was all there on display on the Red Sea. At the top marks, every trick in the book came out when the two boats were neck and neck and at the leeward mark, such is the confidence in the sailing team at the moment that they were throwing the boats around like Go-Karts. A real step-on in technique from the Preliminary Regatta held in Jeddah less than a couple of months’ ago.

Speaking afterwards, Lucien Cujean, a key member of the Flight Control/Trim team at Alinghi Red Bull Racing commented on the sail differences saying: “There is some difference for sure, but then in the moment it's quite hard to see which one is faster than the other so yeah I think as you see on the water it's a lot of boat handling and you have to nail the boat handling before making any conclusions... I think it's hard to make any conclusion, like we really need to sit down and having a proper debrief and let the team analysing our stuff and then we will really see which one won the day.”

That debrief will be fascinating and for the data analysts and coaches, understanding the variances of the high and low aspect mainsail could be key come the heat of battle in the Louis Vuitton Cup round robins in September in variable Barcelona. Alinghi Red Bull Racing’s time on the Red Sea has proven to be a very valuable boost on the learning curve all round. Great sailing from the Swiss. (Magnus Wheatley)