Matthew Sheahan talks to Alinghi's and Oracle's chief designers about how the new Americas Cup class rule will affect the next generation of boats

In the fever that surrounded the announcement of the new venue for the America’s Cup, news of the new class rule for the boats themselves slipped under the net.

During the whistle stop tour of Valencia, it’s city and harbour, little had been said about the local weather conditions and even less about how such conditions might affect the design of the boats over the next three years. This seemed strange given how important local conditions have been in the past. From the famously boisterous conditions in Freemantle to the gentle breezes in San Diego, the weather has always played an important part in the starting point for designers and where collecting and assessing the data has frequently been seen an expensive, tedious and arguably unnecessary part of the campaign process.

But this time around the boats will be grouped more closely under the rule to start with, before the weather’s even been considered.

At the start of each America’s Cup cycle the Defender and Challenger of Record are obliged to re-establish the rules of engagement, part of which involves deciding the type of boats that will compete for the next America’s Cup. In considering what changes would be made and in the absence of knowing where the next event would be held, Alinghi and Oracle sent out a survey in May 2003 to all the teams and interested parties asking for their views on the boats for the next Cup.

“The results of the survey and the idea behind the current rule changes was to maintain the value of the existing boats while still allowing modernisation of the class,” said Ian (Fresh) Burns of Oracle BMW Racing.

“Reducing the cost of taking part was also an important factor when it came to revising the rule as well as trying to tighten up on some potentially expensive areas or development such as the Hula slipping through,” continued Alinghi’s chief designer Grant Simmer.

“There were some, even in our own team, who wanted to see more radical changes for the next time around. Russell [Coutts] felt that the current Americas Cup boats would look old fashioned come 2007 and that the new generation should have the latest technology such as canting keels.

“The trouble is that this would make the next generation of boats very expensive and the overall view was that costs had to be kept under control,” he said.

According to Burns there was a long list of potentially expensive design and construction details that had to be considered and ruled on for the next event. Moulded spinnakers, special paints have been outlawed under the new rule. Heating the hull or the keel bulb to reduce to drag has been considered by some teams in the past, as was the technique of using magnetic fields to achieve a similar advantage, all have been banned for the next series.

“Apart from the idea of reducing cost, another of the goals was to ensure that we get closer racing next time,” said Simmer. “Closer racing allows more opportunities to pass and puts a greater emphasis on crew work. We’re keen to see the boats become closer in performance because we feel we’ve got the best sailing team and I’m sure Fresh feels the same about his team.”

Another factor that has been introduced to try to ensure closer racing from the start is the new ‘anomaly’ rule to help prevent a team turning up with a unique secret feature. There will be a greater amount of openness in the measuring and interpretation too. Unlike previous events, technical interpretations will no longer be confidential but open a year before the start of the Challenger series.

“If you take out all the possibilities for the big changes, teams can spent their time and money on refining what they’ve got,” said Burns. “We believe that this makes for a much better event than the possibility of starting with a boat that’s the wrong length or has the wrong amount of sail area.”

So what will the boats be like for the next Cup?

“Displacements will be reduced and sail areas increased,” said Simmer. “Typically we’re looking at reducing displacement by a tonne to 24 tonnes and a scope for varying the displacement of around 250kg.”

Increasing the downwind sail area by around 7-8% was seen as a way of increasing the chances of overtaking downwind by helping the boats to accelerate quicker as the puffs roll through. But while more sail area is allowed, the variation has been reduced to keep the boats closer.

“Last time around we could vary our sail plan over a range of about 25m2,” said Burns. “Next time around the limit will be around 5-7m2.”

Teams will have one more crew member taking the total working crew to 17 plus one for the 18th man and teams will now have to carry additional 100kg ballast if they don’t have an 18th man aboard.

Among the other changes, keels will be deeper, rigs will be lighter by around 250kg and composite headfoils and forestays will be allowed but non-metallic standing rigging for the shrouds will not.

So, as the America’s Cup circus rolls into action once again, the next round of racing promises to be closer than ever before with a far greater emphasis on crew work than in the past.

Not everyone believes this is what the high octane, design hungry America’s Cup really stands for, but aside from all else, few would argue that close racing doesn’t appeal.