Americas' Cup: AC 75 Class Rule and Technical Regulations published
by America's Cup Media 11 Sep 00:18 PDT
The Challenger and Defender cross the startline on Day 3 of the 2024 America's Cup - October 14, 2024 - Barcelona © Ian Roman / America's Cup
The America's Cup Class Rule and Technical Regulations for the Naples Match have been published.
With the clock ticking down to the start of the Louis Vuitton 38th America’s Cup in Naples in 2027, the AC75 Class Rules and Technical Regulations have been issued to all teams and published with a focus on cost containment.
The decision has been taken to race in Naples with hulls from the Louis Vuitton 37th America's Cup (or modified from the 2021, AC36 versions). In addition, a strict criteria has been implemented with regards to componentry whilst radically changing the internal structure of the yachts by eliminating cyclors in favour of stored energy. What was recognised in detailed analysis was that the hulls themselves represented only minimal advantages, barely recognisable in practice. Furthermore, active cost containment measures in terms of overall team budgets has been laid out in the AC38 Protocol.
Speaking about the Class Rules and Technical Regulations, Dan Bernasconi the Chief Designer of Emirates Team New Zealand and one of the key architects of the rules alongside Athena Pathway’s Nick Holroyd, commented: “We, as a collective between Defender and Challenger of Record, analysed all of the hull shapes used in Barcelona at AC37 and recognised that the speed differences purely of the hulls were minimal. All of the gains were in foils and systems; therefore it made absolute sense to concentrate design time into those areas of development and re-use the hulls. Another big change will come in the electronic management systems, now that cyclors have been outlawed, but the result will be even closer racing and a sustainable event overall.”
The teams will now start work on adapting their AC75s ahead of launch, and in the meantime much training will be concentrated on the AC40 class where teams may use two boats with an eye on the initial three Preliminary Regattas planned for 2026. During those regattas, teams may enter two boats, one of which fields a mix of Youth and Women sailors as set out in the Protocol.
Arguably the headline change is that at least one female athlete is required to be in the five-strong sailing team, and the addition of a fifth active crew-member means greater emphasis on race strategy, positional sailing on the racecourse and bigger picture discussions amongst the teams. The move aligns and brings closer the Women’s America’s Cup Teams of each syndicate as rotation is inevitable, and a deep pool of talent will be required for the length of the campaign from now to Naples in 2027.
Furthermore, the introduction of a ‘Guest Racer’ position on the AC75s whilst racing is a re-kindling of a programme not seen since Valencia in 2007, opening up the pinnacle event in world sailing, the America’s Cup, to the widest audience.
Key points of the new Class Rules and Technical Regulations:
AC75 Class Rule
Key Points:
- Each AC75 will have five dedicated crew members with at least one female sailor required to be onboard as part of the crew.
- A ‘Guest Racer’ cockpit will be implemented, allowing for a non-team member to sail onboard an AC75 during racing – truly the most coveted seat in sailing and a first since the ‘18th person’ guest place used last in the 2007 America’s Cup on the IACC Version 5 boats in Valencia.
- Joint Recon is back with self-declared Observation Days for each competitor. One Design AC40 training is not expected to be covered, but once the AC75s can return to the water from January 15th 2026, the recon programme will be in full swing.
- eChase boats powered by batteries, hydrogen or biofuels to be used by all teams, with a minimum length overall of 10m, a minimum top speed of 35 knots and a range capability of 75 nautical miles.
- The specification of a one-design battery unit that will, when combined, form the primary battery bank that will control all moveable parts on the AC75 will be published in due course.
AC75 Technical Regulations
Key Points:
- Legacy hulls can be derived from either AC37 or AC36 with more tolerance for the adaptation of AC36 hulls from 2021.
- Three legacy foil wings from AC37 can be adapted by up to 20% within tight parameters, and teams are allowed to build a total of three new foil wings, again within set parameters.
- Three legacy foil flaps again can be adapted by 20% and the teams can build a total of five new foil flaps for AC38.
- The one-design foil arm stocks that have remained unchanged since the genesis of the AC75 Class will be re-used in AC38.
- No new masts allowed for the teams that built two masts in AC37. Only one team, Orient Express Racing, built just one mast, so they would be allowed to build another within tight parameters and to a similar design for Naples 2027.
- A total of four legacy mainsails and six new mainsails are permitted; each of these can be re-cut an unlimited number of times as long as 85% of the original remains.
- 13 new jib skins are permitted, plus 10 legacy jibs, making a total of 23 overall for the teams – with the same re-cut permissions as the mainsail.
- Only 1 new rudder permitted.
- Minor modifications allowed to hull form – with just 4 square metres of change allowed to the hull structure (not shape) – to allow for changes to internal systems.
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Changes to control systems, hydraulics and electronics are unrestricted, providing they can be fitted into the existing hull forms.
For all the teams in the Louis Vuitton 38th America’s Cup in 2027, the clock is ticking now, and vital decisions will have to be taken in the coming days and weeks that will decide the overall success of individual campaigns. Selecting where, when and how to train both in the AC75 (from the 15th January 2026) and in the AC40, will be the first key decision for the sailing teams whilst for the designers, a variety of programme avenues will need to be decided in order to modify and enhance the existing yachts. In particular the building and introduction of the three permitted new foils will be absolutely vital with the sailing team requiring time to ‘work up’ each foil and get comfortable with them, against the desire for secrecy until the last moment.
Furthermore, the division of the roles amongst the five-person crew could well see a wide variety of interpretation by the teams. Selecting the squad of sailors for the AC75 and then playing to each individuals’ strength will require analysis and understanding, especially with some big inter-team moves happening since the end of the Louis Vuitton 37th America’s Cup in Barcelona, and the introduction of new faces to the regatta. The fusion of designers and sailors is always a factor in any successful America’s Cup campaign, and the set-up of each individual boat will, undoubtedly be unique.
Maximising performance from all aspects makes the Louis Vuitton 38th America’s Cup one of the most intriguing in the event’s history. Naples is all set to host the most remarkable regatta that will tax the teams operationally, with a tight timescale to delivery.
The above is the official release from the America's Cup organisers, Sail-World will have its own analysis later.
Download the Class Rule and Technical Regulations
www.americascup.com/files/m26296_2025-09-09-AC75-Class-Rule-V301.pdf
www.americascup.com/files/m26295_2025-09-09-AC-Technical-Regulations-V20185.pdf