Emirates Team New Zealand tactician Ray Davies explains the big difference in the pre-start and weather information required in the new America’s Cup form of AC72 racing…

“For the last America’s Cup, there’s so much preparation before the start with the weather team’s information. But this time around the course is quite different. You start at the top of the course, you reach and then go downwind, so you are going into breeze you have already seen. It is not all in the future, like sailing upwind you are sailing into a new playing field the whole time whereas this style of racing, with only a two minute pre-start and then you are off downwind.

“So for the weather team, the type of information from the past is quite irrelevant, especially with the boundaries that we now have on the sides of the course. What will be critical this time around, and for all the teams this is now obvious, is configuring your boat for the weather conditions.

“These boats are going to be geared toward different conditions, with varying foils and sails put on the boat, and it takes time to change these things. So a lot of these calls are basically going to be made the day before. Everyone is in the same boat – if it is going to be 25 knots, it’s a different configuration than if it’s going to be 5 knots, so the weather team is very much geared for the 24 hours forecast.”

The world has been stunned by the bounce back of the Oracle Team.  Obviously, they have a better boat than they did before.  The addition of a world champion tactician no doubt helped, but behind the scenes, there is more.

When this started out, the Oracle team obviously didn't stand a chance.  Then they used their cancel option and spent some time on their boat.  The whole team came back with a smirk and a swagger that has increased with every race, as they licked a winning team within one win of taking the Americas Cup back to NZ.

The confidence shown by the cocky Australian, Jimmy Spithill, at the outset and his smug assurance that the public would see the greatest comeback in racing history, indicates that he knew the changes to his boat would make the difference.  The source of his confidence.  He has behind him technology and money.  . 

The answer is in the foils and Team Oracle seems to have solved a tech problem that has given them an unanticpated advantage.  

The New Zealand company that built both foils and wings is owned by Larry Ellison.  So technical knowledge was accessible, and from the outset, these boats have been a learning curve for all involved.  Most likely, the secret of better performance came up from NZ. - with a price tag. And that would explain how Oracle started winning and a winning team of sailors started losing.

As catamarans these boats fly - without foils.  When they are on their foils, they achieve even more stunning speeds.  However, when they drop speed and are not on the foils, the foils add a drag to the hull, that slows the boat. 

If Team Oracle has solved that problem and improved the foils to retract them into the hull, the advantage would be theirs.  This could explain the smirk and swagger as Oracle has headed out to compete against Team NZ in the final races.

What they probably did:

• Was change the angle of attack to make Oracle get up on foils sooner & stay up longer. 
• A change on Wing control could be another reason - putting more power to the boat so it is getting up on the foils quicker.

This does raise a question on the legality of changing the boat,  Oracle was found guilty of adding weight illegally by an international jury and penalised for cheating.  Could it have happened again?

Note: I think now the foils are here to stay we will see fully retractable foils & possibly changing the rudder foil angle under way instead of at the dock, where it's fixed at present.