Te Aihe's late afternoon beat-up gives insight into AC75 racing for the America's Cup
by Richard Gladwell Sail-World NZ 11 Dec 2019 21:26 PST
12 December 2019
Emirates Team New Zealand - AC75 - Te Aihe - December 11, 2019, Waitemata Harbour © Richard Gladwell / Sail-World.com
On Wednesday for the third time this week, Emirates Team New Zealand put their AC75 Te Aihe, through her paces following the return of Peter Burling and Blair Tuke from the Hyundai 49er Worlds.
Two other sailing crew members Josh Junior and Andy Maloney, are away in Melbourne for the Finn Gold Cup, which starts next week, giving the opportunity for others to get more AC75 experience.
Te Aihe is believed to have undergone substantial modification and enhancements during the two week period behind closed doors at the team base, the team started with two four hour sessions on Monday and Tuesday followed by a monster nine-hour session on Wednesday.
The Wednesday session appeared to be a typical piece of testing - speed runs accompanied by a rest period as data was evaluated, settings checked, and adjustments made. Towards the end, the boat performance seems a lot less erratic, and the development and test process continues.
On the way out, Cup-watchers had the unusual sight of a crew member crawling out on the AC75's raised foil arm to either make a wing flap adjustment, or remove debris.
Returning home in the late afternoon, Te Aihe gives an impression of how racing could look in the Cup, as the AC75 sped up the Rangitoto Channel tacked towards North Head - approaching to within about 50 metres before doing a high-speed roll tack and heading over to the opposite shore. She performs the same manoeuvre off the Tamaki Yacht Club, before taking off at speed up the harbour in her usual mode - flying just above the waves, slightly bow down and heeled to windward.
This was on the area designated as Course C for the 2021 America's Cup - and used for match racing regattas before the courses were moved further up the harbour.
Drawing five metres there is plenty of water close to North Head, a prominent landmark, and extinct volcano, at the entrance to the Waitemata harbour. The AC75 is a jaw-dropping boat to see live, and videos rarely do it justice. Watching a 75ft boat approach at 30kts on foils before spinnings rapidly through a tack, like a downhill skier doing a jump turn, is quite a sight. Somehow whether the boat does a dry tack, or just kisses the water seems irrelevant. However, the speed out of the tack will be a key factor in racing.
Late next week the Match Conditions are due to be published, with wind limits expected to be included. In Bermuda the limit was set at 6 - 24kts maximum measured over a 30 second average in the period of eight minutes to three minutes before the start. Once the three-minute mark was reached (ie three minutes left until the race start), the race would go ahead regardless of what wind strength was reached. For Auckland, given that Te Aihe is seen sailing regularly in winds of 24-25kts, it would seem likely that the Bermuda limit could be increased to 28-30kts. Two rough weather course areas are designated there seems to be a lot more flexibility to ensure that racing is staged in higher wind strengths.
The lower end of the wind range could be set at six-seven knots - whatever the minimum is for foiling in the AC75. Certainly, the foiling monohull is very slow sailing in displacement mode. To get around this same issue in the 2017 Americas Cup with the AC50's, a time limit of 10 minutes applied for Leg 2 (the first downwind leg of the race).
Light weather aside, from what we have seen to date from the AC75, the 36th Match and the Prada Cup will provide the most spectacular racing yet seen in an America's Cup.