It is a special moment when "BoatOne" emerges from the hall on Friday evening shrouded in thick fog. Around a year and a half after Alinghi became the first team to set up in the Barcelona Cup area, it is also the 2003 and 2007 Cup winners who are the first to present a new boat.
With the deep bustle and the open, flat stern, the most striking features are quickly recognised despite the difficult lighting conditions at the launch. This is because the Swiss-built AC75 is a further development of the winning yacht from the last 36th America's Cup. With "Te Rehutai", the New Zealanders dominated the racing off Auckland back then. Used as a training and development platform, the foiling monohull has already shone in the current cycle.
A logical approach for all teams will have been to adapt the design of "Te Rehutai" to the conditions off Barcelona and to make it even faster within the framework of the current regulations. Consequently, the Swiss team has significantly enlarged the so-called bustle on the underwater hull, especially towards the stern. It is deeper, much more voluminous and has a further gradation, a bustle on the bustle, so to speak. Also known as a skeg, these undercarriages were also seen on the British team in 2021 and serve neither to prevent drift nor as ballast. Instead, the wetted surface and thus the frictional resistance of the hull should be reduced as quickly as possible during take-off, while still providing sufficient lift and thus stability.
This "long keel" also acts as a partition during the flight phase. It is driven as close to the water surface as possible and thus prevents pressure equalisation between the windward and leeward side under the hull. This has the same effect as the foresail and mainsail resting on the deck.
Is "BoatOne" immune to Nosedives?
Especially in the demanding waves off the coast of the Catalan capital, which can be up to two metres high in racing conditions, this can be crucial for getting through the waves well or getting back on the foils quickly after a splashdown. If the conditions are particularly rough, "BoatOne" can also be flown a little lower without any problems. The Bustle doesn't slow down much when it dives into individual waves or slides across the water, but immediately provides some lift and stability.
In such conditions, nosedives are always a problem for flying cuppers. In addition to weight savings and aerodynamic advantages, this could have been one reason why the cockpit capsules for the crew on both sides of the hull, which previously extended all the way to the stern, end abruptly well in front of the transom on "BoatOne". The "wings" move slightly towards the centre of the ship in order to ensure that the flow around the hull is as turbulence-free as possible. This was largely made possible by the space gained due to the reduction in the number of crew from twelve to eight sailors in the rules for the 37th America's Cup. The use of cyclists is also permitted again and is expected by many teams.
The completely flat stern eliminates volume in this area, whereby the bow section appears somewhat more voluminous at the same time due to bulges that form a nozzle in the direction of the headsail. The Alinghi Cupper should therefore take off better, provided the stern does not get stuck, which in turn should be ensured by the bustle, and also have less of an urge to dive forwards into the wave.
More revelations expected for the 37th America's Cup - will the New Zealanders land a late coup?
However, the foils will play a decisive role in the battle for the world's oldest sporting trophy. While the rudder holds nothing surprising in store, the main foils have not yet been unveiled. Instead, they were covered by a bulky protective cover at the unveiling and will probably be kept out of the public eye for as long as possible. This is because, as with the Cupper itself, only one set of wings may be built, which will then be used in all conditions. A difficult and pioneering design decision that must be perfectly tailored to the area. Because from a purely sailing point of view, several foils would undoubtedly make sense. However, in order to contain costs, this is not permitted. According to Dr Martin Fischer, Chief Designer at Ineos-Britannia and foil expert, a set of AC75 foils costs three to three and a half million euros with replacement foils.
After the ceremonial unveiling, including a performance by the renowned Catalan theatre group La Fura Dels Baus as a human sail, Alinghi's America's Cupper will nevertheless be prepared for the boat's christening and the first tests in the water over the next few days.
Further unveilings are expected at the same time. In addition to the racing yacht from INEOS Britannia, the French AC75 from the Orient-Express Team and American Magic's Cupper have also arrived in Barcelona well packed. Luna Rossa has announced that it will present its boat for the 37th America's Cup to the public on 13 April. Only the defenders from Emirates Team New Zealand are still unknown some six months before the first starting signal.
