AUCKLAND, New Zealand -- The contentious double hull yacht revealed by America's Cup defender Team New Zealand didn't attract any official protests from rivals before the deadline Wednesday for complaints.

Challengers Alinghi and Oracle had until Wednesday afternoon to submit to the Cup arbitration panel or international jury any protests over the design, which will be essential in New Zealand's February Cup defense.

While Alinghi of Switzerland and Oracle of San Francisco revealed differing but largely conventional design approaches, both of Team New Zealand's race boats unveiled Tuesday featured the snug-fitting and innovative false hull.

Opponents have claimed the design feature, which has been approved by Cup measurers, breaches the intent of the International America's Cup class rule.

Lawyers for Oracle reportedly scoured rulebooks for avenues of protest before the team's rules adviser, Tom Ehman, confirmed no protest would be lodged.

No official protest was received from Alinghi, although the Swiss syndicate put to the jury a series of questions about the false hull, which circumvents stringent restrictions on hull shape because it is classified as an appendage rather than part of the hull.

As an appendage, the false hull, which mirrors the shape of the actual hull, cannot touch the hull at any point other than the point of attachment. It must be rigidly engineered to ensure it cannot flex to contact the hull under the pressure of sailing.

Alinghi's questions concentrate on the methods by which measurers or jury can be certain that the hulls can't tough.

The slightest touch would breach class rules and result in the New Zealand yacht's disqualification.

Alinghi has asked whether an electronic or other mechanism could be devised to monitor the performance of the false hull and to ensure touching does not occur.

Team New Zealand has rejected their rivals' criticisms, saying it would not have been issued certificates for yachts NZL-81 and NZL-82 unless the measurers were convinced of the false hull's legality.

''It was our obligation to prove to the measurers that it doesn't touch the hull and we have proved that,'' said New Zealand design team head Tom Schnackenberg.

The arbitration panel could yet be called on to rule on the legality of the hull if an issue with the design could be found under the Cup's governing protocol.

Further issues can be raised after the challenger finals, prior to the best-of-nine race America's Cup match that starts Feb. 15 or by a red flag protest during racing itself.