Cup Spy: ETNZ looks for a roughing up - chases bigger waves to test the AC40
by Richard Gladwell Sail-World NZ 27 Oct 2022 01:45 UTC
26 October 2022
Alinghi Red Bull Racing `foil-surfing` in the confused Barcelona sea-state © Alex Carabi / America's Cup
Emirates Team New Zealand took off on a tour of the inner Hauraki Gulf on Wednesday, chasing some bigger waves and seeking the answers to a few pressing questions.
Key points October 25, 2022:
- Luna Rossa did not sail LEQ12 off Cagliari being apparently thwarted by light airs.
- None of the other two AC75 teams have sailed since Friday.
- Brits are expected to splash their LEQ12 some time this week from Mallorca, Spain
The images coming back from the AC37 Joint Recon program team based in Barcelona have shown the same rather confused state, which is familiar to others who have sailed at the 2024 America's Cup venue, which 30 years ago was also the host of the 1992 Olympic Sailing regatta.
We saw the the same conditions at the 2008 Olympics in Qingdao, on the final two days when a fresh seabreeze kicked in from the ocean, got manipulated by some weird tidal flows, and and then reverberated off the sea wall, creating havoc in the fleets, particularly the 49er skiffs - where all but one capsized at some stage of the race.
It was a similar situation at the Tokyo 2020 Olympics, where the sea state was less confused and more manageable offshore, than it was on the stadium course alongside the spectators on the seawall.
The point is that the Barcelona conditions are not unique, it is just that they are hard to replicate in Auckland - which is not exposed to open Pacific Ocean swells
The dilemma for the organisers in Barcelona, and other such venues, is that of proximity to spectators and the potential for swell reverberation off the sea wall, conflicts with going further offshore and getting a more regular sea state, but away from the crowds of fans.
The two key issues are whether the AC40 can sail at race pace, in a sizeable swell, with wind chop on top. The key test is to keep the rudder elevator in the water and produce the pressure on the stern of the AC40 to keep it level and avoid nosediving, if it breaks free.
The other is how the auto-pilot, or automated flight control system software can cope with a swell of over a metre, maybe two, and wind chop from a different direction.
In the past AC75's have struggled in some of the bigger sea states that can be found in the Hauraki Gulf, just as the Swiss have in Barcelona.
Rather optimistically the kiwi design/test team hoped for the right conditions on Wednesday. Unfortunately the 15-20kt sea breeze was too recent and too far in the north to deliver the bigger sea state.
But even an adverse tide only delivered a higher than usual chop in a couple of notorious spots where the tide flows the fastest.
"We deliberately headed out into some waves," said ETNZ Head Designer, Dan Bernasconi, in a dockside interview after the session. "We just wanted to see how the boat was handling in waves, looking at the autopilot, looking at maneuvers in those conditions."
On board the AC40 were Peter Burling, Nathan Outteridge, Blair Tuke and Andy Maloney, who took the AC40 on a route around the inner Hauraki Gulf. The worst sea state was in the Motuihe Channel.
"We got waves just over half a metre. It's really, pleasing because it's about going well," Bernasconi said.
"I think it was you'd rather be on the yacht than the chase boat in conditions like that. We are pleased with how the auto pilot is handling it."
"We are going to see conditions with decent waves in Barcelona. We wanted to see how the AC40 was going. Later in the summer we will go looking for bigger swells."
"In Barcelona, we expect to see a huge variety of conditions. Certainly it is pretty exposed and there will be a lot of days with decent waves.
He said that in the last America's Cup in Auckland they could avoid a rough sea-way. "We could always choose bits of water that were relatively protected. This time around [in the build up for Barcelona 2024], we generally will be looking to sail in more open water, by the outer Gulf islands and the northern side of Waiheke Island."
The America's Cup champions have not disclosed their work up strategy for the defence of the America's Cup. But Bernasconi gave some indication of their intended direction of travel. "I think we'll definitely have two boats on the water at times. I think it's really really good for both design development and sailor training, to have two boats alongside each other. Maybe not so much for comparing outright speed, one against the other, but just looking at situations coming off the startline and getting used to having two boats on the course. We'll be making changes to one of those boats, and looking at different foils, different sails, and so on."
Session Statistics - Auckland - October 26, 2022 - Emirates Team NZ - AC40
- Wind Strength 8-18ts (AM) 12-18kts (PM)
- Wind Direction: N (AM) N (PM)
- Sea State: Rough (AM) Moderate (PM)
- Roll out: 1130hrs Dock Out: 1230hrs
- Dock In: 1510hrs Crane out: 1545hrs
- Total Tacks: 36 - Fully foiling: 35; Touch & Go: 0; Touch Down: 1
- Total Gybes: 28 - Fully foiling: 27; Touch & Go: 1; Touch Down: 0
Additional Images of the Day:
This commentary was written and compiled from video, still images and statistical content extracted from the AC37 Joint Recon program and other material available to Sail-World NZ including photo files, and other on the water coverage from the 2010, 2013, 2017 and 2021 America's Cups.