GB1’s refitted AC75 race boat arrives at Naples ahead of 2027 America’s Cup

GB1’s AC75 race boat, code-named RB4, has arrived in Naples after an 800km, three-day road journey from Persico Marine in northern Italy. The boat has undergone a refit for the Louis Vuitton 38th America’s Cup, which takes place in Naples in 2027.

RB4 is the same boat the British team raced at the Louis Vuitton 37th America’s Cup in Barcelona, where it won the Challenger Selection Series. That result made the team the first British challenger in 60 years to qualify for the America’s Cup Match. It also became the first in 90 years to score race wins in the Match.

The 75-foot foiling race boat has been reconfigured to meet the new AC75 Class Rules. These require existing teams to reuse their hull from the previous edition rather than design and build an entirely new boat, with the aim of containing costs while directing development towards areas with the greatest potential performance gains.

One of the main changes is the removal of the four cyclors who generated hydraulic power in Barcelona. For the 38th America’s Cup, the boat’s systems will instead run on stored electrical energy supplied by a specified battery system. The switch requires changes to the internal configuration, hydraulics, electronics and control systems.

The race crew will comprise five sailors, including at least one female sailor. A new Guest Racer position will also allow an additional non-team member to experience racing on board an AC75.

With RB4 now at GB1’s Bagnoli base, the team will complete its final fit-out and commissioning. It plans to get the boat back on the water on the Bay of Naples before the end of 2026.

GB1 CEO Ian Walker says: “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.

“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.

“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.”

Updates from the GB1 camp on the boat and team have been coming fast after some tumultuous months earlier in 2026.

Kitefoiler Jemima Lines (née Crathorne) has recently joined the sailing squad of GB1. It’s a landmark moment in the event’s 175-year history, as it will be the first time the competition has mandated that at least one crew member onboard the AC75 race boat must be female.