Unveiling day revealed all for both Challengers, and an 'elegant' appendage for Team New Zealand. However, it was Team New Zealand who stole the show with the `hula'.
On perhaps the most exciting unveiling day since a victorious Australia II revealed its wing-keel in 1983, the two remaining challengers in the Louis Vuitton Cup, Alinghi and Oracle BMW Racing, and the Defender, Team New Zealand, showed the result of three years of design work and effort in the public 'Unveiling' ceremony on Tuesday.
Team New Zealand followed the Challenger unveilings and stole the show when both of its declared boats, NZL-81 and NZL-82 were slowly raised out of the water to a cheering crowd. It was the first public showing of what had been dubbed the 'Kiwi Clip-On', an elegant appendage incorporated into the hull design that has the effect of lengthening the boat without a rating penalty.
Team New Zealand syndicate head Tom Schnackenberg quickly corrected the name for the appendage, telling the assembled media that his team called it the 'Hula' - an abbreviation of 'hull appendage'.
On both New Zealand boats the 'hula' is an appendage that is separated from the rest of the hull by just a few millimetres. It begins about a metre behind the keel, and runs back behind the rudder, effectively adding length and volume to the aft section of the boat. Designer Clay Oliver went on to say the 'hula' was an integral part of the boat's design.
"The idea starts with the concept that you want to draw a boat that is long, elegant and fast,"
Oliver explained. "It's not a matter of adding something to a boat that you already envisioned. It's actually imagining a boat that you want to have and saying how can we get that shape? This is a solution to that. It's not a clip-on. It's a hull that's been drawn the way we want it and that's the solution."
The other immediately remarkable feature on the Team New Zealand boats were the keel bulbs, both much, much longer than either of the challengers.
Team New Zealand says the 'hula' has been approved by the America's Cup Class measurers and says it doesn't expect to have any problems with protests over the design.
On Monday evening the International Jury received questions regarding the legality of the use of an appendage similar to the 'hula' and requested input by Wednesday evening from the three teams remaining in competition.
Although both challengers, particularly Alinghi have admitted to exploring the use of a similar appendage, neither was sporting a 'clip-on' on unveiling day.
The Swiss Alinghi Team was the first to drop its skirt, after a brief press conference with designers Rolf Vrolik and Grant Simmer.
Alinghi's SUI-64 is the same boat it has used throughout the Louis Vuitton Cup, and is distinctive for its small, narrow and deep rudder. The keel strut on the boat was very wide in comparison to the other boats revealed today and the mast was further forward relative to the keel than the other boats. The keel bulb itself appeared to be similar to that used by Team New Zealand in 2000, with winglets attached at the back third of the bulb.
"Our goal was to come out fast in Round Robin One and just keep moving forward,"
Simmer said. "Today people will focus on appendages and hull shapes, but you shouldn't underestimate the effect of small detail changes and the tuning of these boats. This can result in big differences on the race courses. We've spent over 1100 hours on testing and in-house racing and SUI-64 is product of that work."
"The boat is very narrow, very U-shaped compared to the last generation,"
designer Rolf Vrolijk explained. "This works together with the sail and mast development programme. The appendages aren't very different from what you saw in 2000, but in the details we have worked very hard and made many subtle refinements. We also developed the square headed mainsail that you see on all of the boats now. I think it's clear we have tried to push the engine of the boat as much as possible and all of the other teams are trying to catch up."
In comparison, the Oracle BMW Racing team's USA-76 had a relatively large rudder, and the keel bulb winglets were positioned right at the back of the bulb. The keel strut itself was tapered and shaped.
"We've done a lot of work in the last few months, improving the boat and appendages, the sails and the rig, and we're hoping that we're peaking now in time to beat Alinghi and then Team New Zealand,"
said Oracle BMW designer Bruce Farr. "In comparison to SUI-64 we have a slightly smaller keel fin and it's tapered. Our bulb is shorter and higher and we have our wings at the back of the bulb, rather than the centre of the bulb. We're quite a bit narrower than them, especially at the waterline."
Farr went on to say that although all three boats are quite different, that doesn't necessarily mean we'll see big speed differences.
"You would think that if you all worked hard enough you'd end up with similar designs,"
Farr said. "But there's a combination of features that go together to make a successful boat and a lot of them are fairly flat trade-offs, in other words you can be in different places but have pretty much the same result. So I think the designs get driven by biases in the experiments and even biases in the designer's beliefs. The fact that they look quite different, well the performance could still be fairly similar."
Racing in the best-of-nine Louis Vuitton Cup Final begins on Saturday, January 11th with a 13:15 start gun.
The winner of the Louis Vuitton Cup goes on to meet Team New Zealand in the America's Cup on February 15th. There is another public unveiling before the Cup match on February 11th.