“One of the biggest differences for boat builders is that the new materials are so much easier to handle,” says ABN AMRO builder Killian Bushe. “Carbon drapes more easily on the mould and the Nomex is an easier material to work with too.”

But aside from the ease of handling, the real issue is creating a light hull and deck structure that allows the maximum weight to be used in the keel. “Stability is king,” continues Bushe. “The rules dictate the final weight of the hull by specifying minimum panel weights which are pretty easy to get to for the builders. Making sure you achieve the minimum weight means you have more weight to put in the bulb of the keel, which in turn increases your righting moment.”

And righting moment means power, especially on boats that will cant their keels out to 40 degrees.

But there are other issues concerned with the laminate that will help to increase the potential performance of the boats. Under the rules, a builder can use either wet layup or pre-preg materials, the latter offering a stiffer final structure. This, in turn, means that forestays can be tighter with minimum deflection in the boat, which in turn can help to squeeze yet more performance out of the boat.

There are some like Jason Carrington, who built the ASSA ABLOY boats last time around, who believe that the optimum way to produce a racing boat is to build the hull in a female mould. “The big advantage in using this technique is that you don’t need to fill or fair the hull, so you’re saving the weight of the filler,” he explains. Assuming that the filler weighs around 1kg per square metre, it’s possible to achieve a saving of around 70kg on the whole hull. That’s weight that can go into the bulb. And if you've got a big bulb, you’ve got it all the way around the world. The downside is that the whole process takes longer and it’s time, not cost, that is usually the biggest issue for most teams.” A fact that is particularly important for this event, when crews will face a steeper learning curve when it comes to figuring out what will make these boats tick. Time on the water could well prove to be the crucial factor in success.

This time around, ABN AMRO’s second boat, Ericcson and movistar all used female mould construction, while the remainder, either for economic reasons or time constraints, used the male mould method with consequent fairing on the outside of the laminate.

Another new aspect this time around is the canting keel system. Here the builders are all clear that there are plenty of issues to deal with. “The starting point for this system is that you have a hole in the bottom of the boat, which is challenge in itself for builders,” says Bouwe Bekking of the Spanish movistar campaign.

Carrington emphasises the potential trade off between having a fin that extends well into the interior of the boat and one that doesn’t. A longer lever inside reduces the forces required by the hydraulic rams to swing the keel, but this is set against the extra weight and loss of volume below decks that would result from this configuration. “I think the difference between the best and the worst systems could be as much as 100kg,” he says.

Don Jones, who has designed canting keel boats before, including the Australian super-maxi Skandia Wild Thing owned by Grant Wharington – which admittedly lost its keel in a windy Sydney-Hobart race in January 2005 - and who has now designed the team’s new Volvo Open 70, believes that the Volvo rule provides welcome legislation in a potentially risky area. “The rule specifies a very low allowable stress at around a quarter of what is commonly being used by current canting keel boats. This is helping to highlight the fact that there are no scantling rules for existing canting keel systems. Hopefully this will feed back for improvement and higher safety levels in future designs,” he says, and he should know.

Whatever the variations, one thing is for sure, building any race boat is a time consuming business. Most estimate that a Volvo Open 70 will take around 30,000 hours to put together, which is eight months in real money, or six at a push. Laminating can take up a good deal of this time with aligning the fibres themselves a crucial and time consuming business. As designs become more sophisticated, load paths are calculated precisely by the designers. Ensuring the carbon fibres are laid in the correct manner is critical if the structure is to work. The bulkheads either side of the keel system alone take a month each to build, with complex tapered layers of carbon forming the final structure.

To add to the complication of building a technically complex boat, some, like the movistar team, have chosen to build its boat 10,000 miles away in Australia yet, despite the distance, Bekking sees this as an advantage. “Apart from the skill of the builders themselves, we have found that the time difference has worked in our favour,” he said. “While one side is sleeping, the other can be mulling over ideas or comments that have been emailed earlier. It’s a good way of working things out. “We also set one of our goals as sailing the boat up from Australia to walk part of the course. Even if we had built the boat in Europe we would have shipped it down there to sail it back.” And Bouwe seems to have been proved right, with movistar setting a new monohulls 24 hour record time on passage to Europe.

But, for all the analysis, planning and expert construction, sometimes it is the practical aspects that put things into perspective best. Here, Don Jones likes to take the pragmatic approach at least some of the time. “The new Volvo 70 boats will sail much faster than the 60s,” he says. “As such it’s always good to reflect on the fact that you can make the hull as strong as you like, but God can always make a bigger wave.”