The three America's Cup challengers have launched their boats. Photosport
OPINION:
Ugly can be fast - that's what we're finding out in this America's Cup.
The second generation AC75 yachts just launched by the Americans, British and Italians are not easy on the eye – at least not to a traditional mariner or naval architect.
And from what I hear, things will get even weirder when Emirates Team New Zealand launches its second-generation boat.
The aesthetics of yacht design have a long history. Traditionally, something which looks right usually is. Gentle, even curves, lines without distortion, something that looks balanced and tapered - those have been the indicators of a fast yacht for centuries.
These America's Cup designers have thrown such traditions out of the window, chased them down the street and kicked them into the long grass!
These new hulls have bustles, bumps and distortions, strange angles and flares, and design features which don't even have names yet.
What is going on here?
It's because they are not really yachts at all - they are flying platforms. That's what is driving the hull design. They are designed to fly above the water not on it, because this is faster.
The explanation for the weirdness, at least when compared with traditional yacht designs, is because these AC75 designs are focused on breaking clear of the water and flying as soon as possible. Once in the air, it is very much about reducing drag and minimising touch-downs.
There is also an interesting trend developing in the way these new AC75 yachts are being sailed. The teams are all flying these AC75 mono-hulls bow-down, very close to the surface of the water and with a cant (lean) towards the wind direction.
Speculation is this bow-down windward heel approach allows the sailors to keep more power on and go faster.
An analogy is to think about how the down-force on a racing car's spoilers and wings allow the driver to keep the accelerator floored and corner at high speeds without losing control.
As soon as you reduce power to keep control, you will be slower than an opponent who can keep "giving it some Jandal" (to quote Scott McLaughlin).
An obvious common feature of the three new designs is the longitudinal "bustle" running down the centre of the hulls (Team INEOS is the most extreme so far in this regard).
The reveal | A Look back at Britannia's big day in Auckland! #ThereIsNoSecond pic.twitter.com/yWLAyvoeeE
— INEOS Britannia (@ineosbritannia) October 19, 2020
It appears that the teams have all discovered there are aerodynamic benefits in closing the gap between the water surface and the hulls to direct air-flow fore and aft (front to back) and to minimise the air flowing under the hulls.
Anything that disturbs air flow and creates turbulence induces drag. Drag is slow. This has been well understood in the aerodynamics of sail/wing design for many years. The so-called "endplate" effect seeks to seal off any movement of air between the sail/wing and hull deck. Such air movement is turbulent and "draggy"- which means it slows the platform's movement.
And into her natural habitat she goes! PATRIOT has been launched! @americascup https://t.co/3w4pUpuYqj pic.twitter.com/s5ELFoFCKC
— American Magic (@AmerMagicTeam) October 16, 2020
Luna Rossa’s new AC 75 about to be launched in Auckland this morning pic.twitter.com/yfTHN59j19
— Matt Brown (@chahuahua) October 19, 2020
Yachts from the small foiling dinghies to much larger have all trended this way over recent years by adopting deck-sweeping sails.
The AC75 designers are seeking the same gains by "sealing off" as much air flow as they can which might go sideways under the hull and across the sea surface and instead direct this airflow from front to back.
Another factor driving the "design-it-ugly" trend is that only one set of foils is allowed to be measured in for a race series (including the America's Cup), which presents quite a challenge.
In the last America's Cup regatta in Bermuda, teams were allowed two sets of foils. Typically, they had a light wind set (with more lift created by more surface area) and a stronger wind set (with a focus on lower drag and control at higher speeds).
In Auckland (unlike Bermuda) both the wind and sea-state are highly variable, less predictable and multiple courses can be used. As a result, an all-round foil set is imperative, a specialist set far too risky.
The designers must find hull shapes which break the holding tension of the water surface as easily as possible and minimise the risk of a touch-down turning into a race-losing "sit-down" into the sea. If the hull form can do this more readily, then the foil package can be made smaller – which means they have less drag and, therefore, will be faster.
So, a primary design adage – that form follows function – is present in these new designs. The teams have learned a lot from their testing, spying, analysis and simulation over these past two years but their flash graphics cannot hide the fact that they are strange looking beasts.
It must have been particularly difficult for the Luna Rossa team who have always placed a high priority on looking good – with Italian style – to launch the weird looking thing they did on Tuesday. That said, somehow, they have still managed to make it look cool.
In the end though, ugly will quickly become beautiful if it wins. And the eye adjusts to the new normal.
We now await the launch of ETNZ's second-generation boat/flying machine. By all accounts it is even further out there in terms of the weirdness factor. Perhaps that is a good thing.
What is clear is that these second generation AC75 flight platforms are very different from the first-generation designs.
We will find out how fast ugly really is when the speculation ends and the racing begins in the week prior to Christmas. It will be fascinating. Bring it on.
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Professor Mark Orams is the Dean of the Graduate Research School at Auckland University of Technology and is a former member of Team New Zealand. He was also part of Sir Peter Blake's winning Whitbread around the world yacht race crew aboard Steinlager 2.
A former Team NZ sailor believes Luna Rossa have gained a lot with the signing.