GB1’s AC75 race boat has arrived in Naples, marking a major milestone in the British team’s campaign for the Louis Vuitton 38th America’s Cup. The boat, code-named RB4, completed an 800km, three-day road journey from Persico Marine in northern Italy, where it underwent an extensive refit to prepare for the next edition of sailing’s most prestigious competition.
RB4 is the same AC75 that raced for the British team in Barcelona at the Louis Vuitton 37th America’s Cup, where GB1 made history by winning the Challenger Selection Series. The team became the first British challenger in 60 years to qualify for the America’s Cup Match and the first in 90 years to score race wins in the Match.
Now stationed in Naples, the 75-foot foiling race boat has been through a major programme of work to reconfigure it for the new AC75 Class Rules governing the 38th America’s Cup in 2027.
Under the updated rules, existing teams must reuse their AC75 hull from the previous edition rather than design and build an entirely new race boat. The change is part of a broader effort to contain costs while focusing design and development on areas that can deliver the greatest performance gains.
The AC75s racing in Naples will be significantly different machines from those seen in Barcelona. One of the biggest changes is the removal of the four cyclors previously used to generate hydraulic power. For AC38, the race boat’s systems will instead be powered by stored electrical energy through a specified battery system, requiring significant changes to internal configuration, hydraulics, electronics and control systems.
The race crew will consist of five sailors, with at least one female sailor mandated to be onboard. A new Guest Racer position will also allow an additional non-team member to experience racing onboard an AC75.
Following its arrival in Naples, RB4 will now enter its final fit-out and commissioning phase at GB1’s Bagnoli base. The team is planning to begin sailing the AC75 on the Bay of Naples before the end of 2026.
GB1 CEO Ian Walker said: “It’s a significant moment for the team to have the AC75 arrive here in Naples. This is a boat that means a huge amount to us. It helped us make history in Barcelona by winning the Challenger Selection Series and taking a British team back into the America’s Cup Match after 60 years.”
Walker continued: “But what arrives in Naples is also the starting point for the next chapter. The rules for this Cup mean we are reusing the same hull, but there is a huge amount of development taking place across the boat, particularly around the foils, systems and electronics.”
He added: “The team with the support of Persico Marine has put a tremendous amount of work into the refit, and we now move into the final fit-out and commissioning phase here in Naples. Getting the boat back on the water before the end of the year will be another important milestone and the start of an incredibly important period of testing and development for us.”
