Team New Zealand's Peter Burling has given insight into what it's like sailing their second-generation AC75 Te Rehutai, revealing the struggle of maintaining its control at high speeds.
Team NZ have spent the past few days practising on the Waitematā Harbour ahead of next week's World Series and Christmas Cup regatta.
Although hesitant on giving exact figures on the new boat's speed, Burling said it was "incredible" how fast they had got at times.
"The best way to understand the speed is to compare it back to the boats we were racing in Bermuda, and they're significantly faster than that," Burling told Newstalk ZB's Martin Devlin. "This time around is almost as big a jump as it was from the version five boats after the [catamarans] in performance."
With such speed comes the challenge of control, however, to which Burling said was an extreme balancing act.
"The margins of getting it right and wrong are pretty tight, generally the harder the boat is to sail, the quicker it goes. It's just about recalibrating to the speeds they're doing," he said.
"It's definitely quite on edge but you're in control while being on that knife-edge, all the time you're deciding how hard you want to push things. There are definitely times you're a little bit out of control - when you're trying to transition through something or you've made a little mistake, but generally, they're pretty short periods where you're more just trying to regather it.
"I'd say 95 per cent of the time you're in control."
Burling had the edge on Jimmy Spithill and Luna Rossa in the first practice race on Course E earlier this week and held a lead of more than 30 seconds after two legs when the trial ended.
Team New Zealand trailed in the second "race" of the day before finding some extra speed to chase down the Italians, again holding the initiative when the session finished. The third was more clear cut, with the local boat sailing off into the distance.
Although the practice results were encouraging, Burling warned it might not necessarily replicate how things go down next week and in the America's Cup in March.
"These boats have changed so much in the last little while ... there's a lot of new components set to come on the Challenger's boats and new components to come on our boat," he said. "But at the end of the day you're just racing yourself and trying to make sure you're as well prepared and as fast as you can come the start line.
"Right now, it doesn't matter who has the edge per se but it's just been a good time to check-in with where teams stand."
Team NZ, Luna Rossa, INEOS Team UK and American Magic will go head-to-head in the World Series from Thursday.
Enjoy smooth sailing to the Cup with Auckland Transport
• Avoid traffic congestion and parking niggles and download the AT Mobile app to plot your bus, train or ferry ride to race venues before you leave home.
• Make sure your AT HOP card is in your pocket. It's the best way to ride to the Cup
• For more ways to enjoy race day, visit at.govt.nz/americascup