AmericaOne will use USA 61, while Prada has chosen ITA 45.

AmericaOne's USA 61 is the newer of the two boats they have built for this campaign. The 80-foot hull was airfreighted to Auckland and launched here in November.

ITA 45 is the first of two boats that Prada launched in May last year and was used in the first two rounds of the Cup before being replaced by the newer boat for the third round.

When he bought out his newer boat for the semifinals, Cayard said "the reality is that 61 is simply a better boat than 49, (the older boat)," and his view hasn't changed.

Francesco de Angelis isn't quite so emphatic about the benefits of his boat.

"There has been a lot of thought, and we are going to use ITA 45," he said.

"We picked 45 because we think it is the boat that will fit the kind of racing we are going to have," he said.

AmericaOne, from San Francisco, and Prada, from Punta Ala in Italy, are the two finalists out of 11 challengers from seven nations that started the Louis Vuitton Cup in October last year.

The Louis Vuitton Cup is the series to select the challenger that will meet the holders of the America's Cup, Team New Zealand, starting on Feb. 19.