For fans there is a great deal of silence between America's Cups, but the teams have been working 24/7 since 2021. With a little over 1 year to go what have the teams been up to?

Several years after Emirates Team New Zealand successfully defended the America’s Cup back in 2021, we are about to see racing in this cycle for the first time. But what have teams been up in the last couple of years as they look ahead to the 2024 America’s Cup?

The first official event of the 37th America’s Cup will take place from 15th September 2023 as the five America’s Cup teams gather in the Catalonian port of Vilanova i la Geltrú for the first America’s Cup Preliminary Regatta.  The racing itself will take place in the One-Design AC40 class, which might make for entertaining racing, but will show us very little about where each team is in their technical development path towards the ultimate goal of winning the 2024 America’s Cup.

So what have the teams been up to since the last America’s Cup in 2021?

INEOS Britannia and Orient Express Racing Team training in their AC40s

America’s Cup test boats and AC40s

Every team entered into the 2024 America’s Cup needs to purchase a one-design foiling AC40 for racing in the Preliminary Regattas and to ensure they can enter teams into both the Women’s and Youth America’s Cups (both of which will use AC40s).

All teams set to take part in the 37th America’s Cup now have AC40s on the water in preparation for the America’s Cup Preliminary Regatta. However, some have had them on the water longer than others, and some have two out on the water sailing.

Although the AC40 is a one-design class and must adhere to strict rules for the Preliminary Regattas and the Youth and Women’s AC, outside of these events they are allowed to be modified in order to conduct testing ahead of the launch of team’s AC75 America’s Cup boats – though they must be able to be returned to their one-design configuration for racing.

Oreient Express Racing Team were the last to launch an AC40

The French Orient Express Racing Team were the last team to enter this America’s Cup and were also the last to get an AC40 – only launching it in mid-August. And as such hold the difficult duel position as both last team to enter the Cup and the team with the least time on the water.

By contrast, Defenders of the America’s Cup, Emirates Team New Zealand were the first to launch an AC40 back in 2022 and were the first to conduct two-boat testing once their second AC40 was launched.

Neither of these outcomes are a surprise, with a single builder of AC40s, teams were allocated a build slot based on their order of entry to the 37th America’s Cup.

In terms of boat launches, teams have taken a number of different approaches. With a wait for AC40 delivery and time of the essence (as ever in the AC), some teams chose to build their own training boats.

Boat terminology has become a little confusing, but test platforms are generally referred to as LEQ12s (short for ‘Less or Equal to 12m’ the parameters for a test platform as defined by the America’s Cup rules, to limit teams building platforms too similar in size to an AC75).

Luna Rossa Prada Pirelli training in their LEQ12 in Cagliari

The two teams which have chosen this route are Challenger of Record, INEOS Britannia and Luna Rossa Prada Pirelli. To add a little more confusion to the nomenclature, Luna Rossa refer to their boat as simply LEQ12 while the Brits have named their ‘LEQ12’ T6. Both of these were launched in late 2022.

For both of these teams, their LEQ12 has been the primary test platform, with both also adding AC40s to their roster of boats following the launch of their LEQ12 test platforms.

To further confuse the issue, if teams take an AC40 out of one-design configuration that too becomes (officially) an LEQ12. This is because there are limits on the number of parts any team can design and own. So an LEQ12 can have a certain number of test foil shapes (for example) and this same rule applies to foils on a non-one-design AC40.

Emirates Team New Zealand training on one AC40 and one modified AC40 (officially a LEQ12). Photo: Ugo Fonollá / America’s Cup

In addition to AC40s and LEQ12 test boats, teams are also able to sail their AC75s from the 36th America’s Cup, though with limitations on when they can be sailed. These limitations vary somewhat with teams that took part in the last America’s Cup, who already have AC75s, more restricted than new entries, who were able to purchase an AC75 and sail it earlier in the cycle.

Alinghi Red Bull Racing are a new entrant in this Cup cycle and they purchased Emirates Team New Zealand’s first AC75 from the 2021 Cup cycle and relaunched it in August 2022 immediately getting some time on the foiling monohull under their belts. They have since relaunched once again after adding some further developments.

They have split their time between AC75 sailing and AC40 sailing, once their own one-design was delivered, and have recently been two-boat tuning with the delivery of their second AC40.

Sailing ‘legacy’ AC75s will be a key part of the build up to the next America’s Cup, with teams only allowed to build one new AC75 this time around (two were permitted for the 2021 Cup).

“The rule that you can only build one AC75 this campaign is to save cost, but it’s a big change from the America’s Cup that I grew up with, in the old IACC class monohulls,” explained Jeff Causey, INEOS Britannia’s boat operations manager. “Back then, it was all about two-boat testing. Every team that could afford to designed and built two boats, and then lined them up against each other for countless hours of side-by-side tuning out on the water. We don’t have that available to us this time.” 

American Magic out two-boat testing. Photo: Paul Todd/America’s Cup

The USA flagged team, American Magic has taken a similar approach to Alinghi Red Bull Racing, getting plenty of time out on the water onboard their AC75 from their base in Pensacola and sailing their first AC40 there too, before moving out to Barcelona earlier this year where they got their hands on their second AC40 allowing them to get some two boat testing and training under their belts.

It should be noted that the AC75 rules have been slightly tweaked for this edition with ‘cyclors‘ once again allowed and some changes to the foil arms and sail control systems – among other tweaks. And we have seen teams making changes to their legacy AC75s to reflect this, with many teams opting for cyclors at this early stage.

Emirates Team New Zealand training on an AC75 with cyclors now returned to Cup sailing . Photo: Job Vermeulen / America’s Cup

Testing, data collection and simulators

Two boat testing provides a clearly defined development path for those who choose to do it and can be used to either validate technical data (e.g. how well different foils perform) or team performance using identical kit to race each other.

This type of A/B testing has been key to producing a fast boat and a well oiled sailing team since time immemorial. However, the America’s Cup is at the very forefront of technology and gone are the days of relying purely on such simple tools.

It’s widely accepted that one of Emirates Team New Zealand’s key advantages back in 2017 when they wrested the America’s Cup from the hands of then Defender, Oracle Team USA was the Kiwis’ reliance on simulation tools. And an accurate simulator has remained the holy grail of the AC world ever since.

INOES Britannia’s LEQ12 is bristling with sensors. You can make out one camera here, above and aft of the foil arm buried in the hull, surrounded by carbon there are hundreds more load, speed etc. sensors. Note also the two differing foil shapes. Photo: C.GREGORY / INEOS BRITANNIA

It is here where we are likely to see the key benefits for those teams who have got together with F1 teams – Alinghi Red Bull Racing (Red Bull) and INEOS Britannia (Mercedes).

The key thing here is that teams will want to capture as much data as possible from their test platforms in order to validate their simulator findings. Put simply the closer to real-world sailing you can make your simulations the better and this relies on adjusting the simulation output based on how well it corresponds to real world scenarios.

As such we have seen boats bristling with sensors and cameras all sending high quality data back to huge data banks largely in order to calibrate simulators.

Foil mounted aft with a bulb protruding forward as we saw in the last Cup.

Foils and sail controls

The upshot of a good simulator is that it significantly reduces the need for real world testing of ideas. In short, why design and build a foil to put through two-boat testing when you can build thousands of simulated permutations of different foil types?

But we have seen teams testing different foil shapes in the real world too, with some teams electing to A/B test foils on a single boat by running different foil configurations on port and starboard – something we saw a lot of in the last Cup cycle.

From what can be observed from the testing to date, there seems to be a consensus around the foil wings themselves sitting as far aft as possible on the foil arms, usually with some kind of bulb projecting forward. This is the style of foil Emirates Team New Zealand used in their successful defence of the AC last time out.

Sail controls will once again be a significant development area.

Once again, though foil shapes are a key area of development with flat elliptical foils a popular option, Y foils on display as well as curved foils (somewhere between a flat and Y-shaped foil) and the recent return of a W foil by the Brits (trialled and eventually dropped by them before the last Cup).

While foils were a key visual difference between the boats last time around, sail control setups were also a marked area of differentiation. Some teams had boomless setups, some had a boom, Luna Rossa had a sort-of-boom hidden underneath the deck and INEOS used (and then abandoned) an articulating boom.

There was a lot more experimentation beyond the booms and a significant amount of development was hidden within the boat and between the sails.

All of these differences were in order to get the twin-skin mainsail to be as powerful as possible to provide drive for the AC75 to get up on it’s foils and then allow rapid depowering and aero efficiency once foiling and contenting with apparent wind speeds of around 50 knots.

It looks as though sail controls are once again going to be a significant area of development. More so than the foils, sail controls and systems are very well hidden but we have already seen a mixture of boom and boomless setups on test boats and there are rumours that this is a rich seam of development once again this time around.

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