Team New Zealand have unveiled their latest weapon, a sail which could sink Luna Rossa's America's Cup hopes in very light airs.
Experts are surmising the large, traditional style of sail forward of the mast would enable Te Rehutai to keep battling towards the finish line if the wind was so light she could not stay on the foils.
TNZ did not reply when approached for a comment about the latest potential addition to their weaponry.
But bad memories from an abandoned race in San Francisco eight years ago might have stirred their design creativity leading to the displacement sailing addition.
In 2013, TNZ were heading for Cup victory in race 13 of the final. But the race was abandoned because it exceeded the 40-minute limit, and Oracle Team USA went on to score its miraculous comeback victory from 8-1 down.
Sailing observers have told the Herald they wondered what might be in the pipeline, after a crazy Christmas Cup race between TNZ and Ineos Team UK during this regatta.
TNZ were robbed of victory in that race, their massive lead counting for nothing after the boats were stranded in light airs and couldn't satisfy the 45-minute time limit.
World champion sailor Phil Robertson says he wondered at the time what the teams might come up with to cover that sort of situation.
"They would have asked 'what could pull us downwind when we can't foil?'" said Robertson, who did not have first-hand knowledge of the new TNZ sail when talking to the Herald.
A leading sailing identity confirmed to the Herald they had seen TNZ on the water with a new full-sized sail.
Another said it appeared to be made of a traditional type of material, rather than carbon fibre used on the AC75s. It has been seen operating along with the mainsail and jib.
Under the AC75 rules, teams were allowed to use a jib and large Code Zero along with the mainsail.
But the Code Zero, designed for foiling, was abandoned without ever being used in anger because of its very narrow wind range.
Nothing stands still in the big-money, high-tech world of America's Cup sailing however.
The winds tend to lighten on the Waitematā Harbour at this time of year. America's Cup races only go ahead if an average wind speed of 6.5 knots, over five minutes, is reached before the race. Once a race starts it continues no matter how low the wind drops.
Robertson said there would be a lot of logistical issues to overcome in furling and unfurling the new sail – which would be no good upwind – during a race.
But he described its appearance as "interesting".
Race director Iain Murray said he had no knowledge of the new sail but was sure it would meet any rules requirements.
"There are very smart people at Team New Zealand – they won't be wasting their time and money and energy on something they might not be able to use in races," he said.
"If there is any doubt they put it in for confirmation."
AUT Sailing Professor Mark Orams said this was the perfect time for TNZ to unveil the sail with the America's Cup match starting on March 6, giving the Italians little time to match it.
Heading into the Cup racing?
• Give yourself plenty of time and think about catching a ferry, train or bus to watch the Cup.
• Make sure your AT HOP card is in your pocket. It's the best way to ride.
• Don't forget to scan QR codes with the NZ COVID Tracer app when on public transport and entering the America's Cup Village.
• For more ways to enjoy race day, visit at.govt.nz/americascup.