Grant Dalton says Team New Zealand has taken a "clean sheet of paper" to their new boat, but admits its new design and shape is a bit of a risk.

Speaking to Newstalk ZB's Mike Hosking, the Team NZ boss revealed the motivation behind the America's Cup holder's bold new AC75 'Te Rehutai' – named after the Māori word for sea spray – which was unveiled last night.

The large crowd who lined vantage points around the launch at the Team NZ base in Auckland's Viaduct Harbour were treated to their first glimpse of the new-look second boat, which had a distinctly different shape that was more concave rather than its fuller formed predecessor 'Te Aihe'.

"We took a clean sheet of paper to it because the class is so new and it has so much scope for development," Dalton said. "After we launched boat one, we said 'that's got us to a level, now we want to go as far as we can'.

"The way we always think about it, last time we talked about throwing a ball as far as you can; this time we say don't design the 2021 boat, give us the 2023 boat this time. That kind of allows the designers to expand their thinking. There's no bad ideas and we're an organisation that just encourages big ideas and I think that's what you saw last night."

Team New Zealand launch their second AC75. Photo / Supplied/Team New Zealand

Dalton admitted that the new look second boat is a risk "in theory" but was confident in the work and preparation that has gone into it.

"Time will tell whether we've made the right choices or not," he told Newstalk ZB. "But we have very strong simulation tools now in the same way that Formula One does. So we can pretty much model, provided the physics of the simulator are correct, what the boat will do.

"It looks like a big jump; it is a big jump. But we're confident in it just simply because the simulators and tools tell us it's just fine."

Dalton said the seemingly drastic changes was not an indication of the lack of success of the first boat, but simply a sign of Team NZ's ambitions in trying to push the second boat as far as they can.

"We put boat one to where we thought we could get to in that time frame. We've taken this as far as we can in the time frame we've had. We're happy with boat one. But happy is never going to win the America's Cup for you. You've got to be out on the extremes and you've got to be prepared to accept risk.

"Sometimes it's balanced risk and sometime it's not so balanced. And that's one of the skills that our guys understand that there's no risk, no reward but don't put it in a spot where it's just a hail Mary because then you would be in trouble."

Grant Dalton says the new boat rewards accurate sailing. Photo / Brett Phibbs

Dalton also said the new boat rewards accurate sailing, which gives Team NZ's world class sailors the best opportunity for success.

"We've now moved into the sailing phase rather than just a computer building phase. They are tricky boats to sail and they reward accurate sailing. So if you're jumping all over the place, up and down, in the air, you're not going to be pushing forward well enough.

"Particularly between now and Christmas, the guys will sail as much as they can and just try and get the maximum out of what we have.

"We will never stop developing. You cannot. They don't count points for the first race of the America's Cup and they don't count the results of the last race. You have to stay developing all through that period."

Team NZ were by far the last team to unveil their second boat, with all three challengers well in the water weeks before the Kiwis.