Veteran New Zealand sailor Chris Dickson is impressed with the black boats, but has concerns as to how Team New Zealand will fare upwind against Alinghi.
Throughout the challenger series, Russell Coutts' Swiss syndicate blew most of their opponents away on the first beat and were able toincrease their lead on the upwind legs.
That early advantage was usually enough for Alinghi to win the match.
In the 12 times Dickson's Oracle syndicate raced Alinghi in the challenger series, 65 per cent of the time Alinghi made gains in the upwind legs.
"We found Alinghi to be a strong upwind boat," Dickson said yesterday. "In the eyes of all the challengers they were strong upwind. So it would be unreasonable for Team New Zealand to think otherwise. They will have to be alert upwind."
The hull appendage (known as the hula) on both Team New Zealand yachts, NZL81 and NZL82, adds volume and length to the hull, and therefore potential speed.
"The hull appendage isn't a race winner, but it will help," Dickson said.
But the hula comes at a cost.
The small gap between the appendage and the hull creates friction drag, and the need for a rigid hull structure adds weight - both of which are disadvantages in light air, particularly upwind.
"Once you fully power a long boat you can expect it to be faster," said Dickson.
"But in light winds the drag from the gap is bigger, and having a longer boat is not necessarily a good thing either.
"I'd expect Team New Zealand to be strong upwind in moderate and fresh conditions, and fast in all conditions downwind."
Alinghi have modified the shape of their bow, giving it more volume.
The modifications are aimed at increasing the length of their boat to combat Team New Zealand's possible speed advantage.
Dickson was recently reported on a sailing website as saying if he could give Team NZ any advice it would be to analyse Alinghi's time, distance and positioning at the start, and also work on their upwind tactics and defending and attacking downwind.
"I think Team NZ are going to win, but I am not going to say why."
The cup match is a best-of-nine series starting on February 15.
