AUCKLAND, New Zealand -- Seattle's OneWorld Challenge made major modifications to its race yachts Wednesday, preparing for the start of its series Friday against Oracle.

Spokesman Bob Ratliffe said the syndicate of mobile phone pioneer Craig McCaw hadn't decided whether it will sail USA-65 or USA-67 in the best-of-seven series from which one team will join Switzerland's Alinghi in the January challenger final.

"We've made some major modifications to our boats and the team are out there testing them today,'' Ratliffe said.

Ratliffe would not say whether OneWorld was experimenting with the innovative false hull revealed this week as defender Team New Zealand's secret weapon for February's Cup match.

"We're certainly aware of what others are doing and we're doing our own research,'' he said.

OneWorld advanced when it eliminated Prada of Italy 3-2 Tuesday in a shortened semifinal series.

In advancing to the second-to-last stage of the challenger series, OneWorld managed to overcome a one-point penalty imposed on it by the Cup Arbitration Panel last week for possessing its rivals' design secrets.

OneWorld will carry the same penalty into the series with Oracle and into the Cup match, starting Feb. 15, if it advances that far.

Chief executive Gary Wright said OneWorld was determined to overcome the disadvantage of its pre-race handicap.

"These last couple of years have been quite tough for us, and we've had quite a few hurdles put in our way,'' Wright said. "But the team just seems to keep rising to the challenge and dealing with it once again, so I have every confidence that they'll do it next time, too.''