French AC75 relaunch

The 75-foot foiling monohull, now carrying the colours of title partner La Roche-Posay, returned to the water on Monday in Lorient, where the team has been working through an extensive modification program. The campaign says the partnership with La Roche-Posay is built around science, innovation and performance, with the America’s Cup providing an extreme marine test environment for sun protection and skin repair products exposed to UV, salt, wind and high-performance sailing conditions.

While the AC75’s silhouette remains familiar, the boat has undergone substantial technical changes since the last America’s Cup in Barcelona. Under the rules for the 38th America’s Cup, teams that competed in the previous edition must build from an existing hull, shifting development away from an all-new platform and toward systems integration, appendages, control, energy efficiency and reliability.

The French boat’s main hull remains, but the deck plan, cockpits, weight distribution, control systems, electrical systems, hydraulic circuits and crew ergonomics have all been revised for the next cycle. The changes are designed to meet a revised rule framework, including a reduction in crew numbers and the replacement of human-generated hydraulic power with battery-based energy systems.

“A launch is always a special moment,” said Antoine Carraz, Technical Director of La Roche-Posay Racing Team.

For months we’ve been working on plans, simulations, parts and systems. On the day the boat returns to the water, all these elements must work together. It is both the culmination of an initial phase and the start of the real validation work.”

The 38th America’s Cup AC75 rules have reshaped the onboard architecture. In Barcelona, AC75s carried eight crew.

In Naples, each boat will carry five sailors, with at least one woman required on board. For the technical team, the reduction is not simply a matter of removing three positions; it changes the flow of communication, the layout of controls, the distribution of tasks and the way each sailor interacts with the boat at speed.

“Going from eight to five crew members changes everything: ergonomics, communications, the division of tasks and the control systems,” said Carraz. “With fewer people on board, every action must be simpler, more direct and perfectly coordinated. We have worked to ensure the boat remains extremely high-performance without becoming more complicated for the crew to operate.”

A sixth cockpit is also planned for a guest during training and racing. The guest will not take part in handling the boat, but will be able to experience racing from within the AC75 platform.

Another major change is the removal of cyclors, the athletes who generated hydraulic power by pedalling during the 37th America’s Cup. In the next edition, power will come mainly from batteries, requiring a significant redesign of the electrical and hydraulic systems.

“The disappearance of the cyclors is a major development,” said Carraz. “Previously, part of the performance depended directly on the sailors’ ability to generate power. Now, we have to manage a certain amount of on-board energy. We need to store it, distribute it and use it at the right moment, with the best possible efficiency.”

As with high-performance electric motorsport, the challenge is not only how much power is available, but how efficiently it is used. The team’s engineers are working across battery consumption, cooling and system reliability, with repeated manoeuvres and small adjustments likely to influence the energy balance across a race.

The AC75 remains one of the fastest and most technically complex racing yachts in the world. Measuring 75 feet, or 23 metres, it is capable of lifting its hull clear of the water on foils and reaching speeds above 50 knots. Behind that spectacle sits an integrated system of aerodynamics, hydrodynamics, electronics, hydraulics, materials science and human control.

The boat collects thousands of real-time data points, including speed, ride height, appendage loads, sail settings, hydraulic pressure and power consumption. Under the rules, however, this data cannot be used to create an autopilot. The decisions remain with the sailors, putting a premium on interface design, control layouts and the clarity of onboard information.

“The aim is not to replace the sailor with a computer,” said Carraz. “It is to provide the sailor with the right information at the right time and to ensure that their command is carried out immediately. At these speeds, a control that is difficult to locate or information that is poorly presented can cost a great deal of ground.”

With the hull largely fixed, much of the competitive development will come from areas less visible to spectators: foils, rudders, sails, flight-control systems, deck aerodynamics and cockpit configuration. The first Lorient sea trials are not expected to represent the final Naples set-up; instead, they provide a baseline for the next stage of measurement, comparison and refinement.

“The first launch does not represent a final configuration,” said Carraz. “It gives us a working basis. We will measure, compare, understand and gradually refine the boat. In the America’s Cup, performance rarely stems from a single great idea. It arises from hundreds of details that ultimately work together.”

Before returning to the water, much of the development work was completed through digital modelling, structural analysis, airflow and water-flow simulations, systems analysis and bench testing. The first outings in Lorient now move that process into real conditions, with safety and reliability the early priorities.

The team will assess system behaviour, power use, operating temperatures, equipment communication and the crew’s ability to work from the redesigned stations. Each session will produce large quantities of data to be analysed ashore and compared against crew feedback.

“During the first few sorties, we won’t be aiming for top speed straight away,” said Carraz. “We’re taking it step by step. We need to check that all systems are performing as expected, then gradually increase the load and intensity. Performance can only be achieved once the boat is reliable and fully understood by those who sail it.”

Designed in Vannes in 2023 and now prepared and operated from Lorient, the AC75 draws on expertise from elite sailing, marine engineering, digital technology, electronics, hydraulics, materials and applied research. For the French campaign, the boat is both a sporting platform and a symbol of national technical capability.

“The La Roche-Posay Racing Team’s AC75 is the result of a collective effort,” said Carraz. “Behind the five sailors we’ll see on board are engineers, technicians, builders, electronics specialists, hydraulics engineers and numerous partners. The launch gives a visible form to all this work. From today, our aim is to translate this technical expertise into performance on the water.”

Stephan Kandler, CEO of K-Challenge, said the relaunch followed the team’s strong start at the first official regatta in Cagliari in May and marked an important milestone for the program.

Seeing our AC75 sail for the first time in France is a highlight for the whole team,” said Kandler. “This launch marks the culmination of months of work carried out in Lorient by our sailors, engineers, technicians and all our partners.

“Being the third team to relaunch its AC75 demonstrates the momentum we have built up and the progress made since Barcelona without ever stopping. In its new livery, the boat fully embodies the project we are building with La Roche-Posay: a long-term French campaign based on science, innovation and the pursuit of performance.”

La Roche-Posay Racing Team will train in Lorient from 29 June to 17 July, then again from 1 to 14 August. The team is scheduled to move to Naples between mid-August and the end of September, ahead of the Naples Preliminary Regatta in the AC40 class from 24 to 27 September. AC75 sailing in Naples is expected to begin in October as the countdown continues toward the 38th America’s Cup in 2027.

americascup.com
k-challenge.fr