Pre-Match UPDATE .... Feb 24th, 2021   

                                               Final Post Race Update added below,  March 20th, 2021

Well, Luna Rossa had hardly come ashore after her final win, when a few emails came in asking for my prediction for the eventual AC winner!

Look guys, I have no crystal ball and as we’ve seen in the past, remarkable things can happen, like that incredible 9-8 comeback after being down 8-1 in the US a few years back.

But that said, I do have some thoughts I can share with those interested.  After all, we do get bolder (or balder?) with age ;)

First, is Luna Rossa a surprise as the final Challenger ?    Hardly.   As the first challenger to NZ after their previous AC win, they became The Challenger of Record.  This means they become the principal representative for ALL the challengers and are the only team that sits at the table with potential input into the Protocols and Design Specs for the new boat.     They would be hearing the NZ team speak on all related subjects, so it’s hardly surprising that their initial boat was fairly close to that of NZ and also, that their 2nd boat that they now race, is also the closest to their first boat, with relatively small refinements.   They also have arguably the most experienced match-racing skipper on fast, foiling boats on the planet, even if his helmsman role is partly shared.   (But a footnote: a Challenger of Record has never actually won the Cup as yet ;)

While the Americans can always be expected to put up a close challenge, they were hit hard this time with several setbacks .. including that disastrous crash that had them lose not only a critical race they were winning, but then lose a full week of essential competition on the water.   It was all downhill from there.  

Of the 4 countries competing, the British challenge had to be the long shot.   They have not managed to get even close to taking the Cup over the last 50 years of its history even though they had put together a pretty strong team on paper this time.    Most teams got their first boats going at a fairly competitive pace last December but the first UK boat (including foils & sails) was so far off the pace that they could not win a single race in 2020.     Good for them, that they corrected things quickly and came out with a totally new boat, mast, sails, reworked foils etc., that then did pretty well in windy conditions.   But the proven way to reach the pinnacle of any sport, is to first get close to the top to be seriously competitive …,and then tweak things that little bit more, to finally become the best.    With that first boat SO totally out of it, they would need a (not permitted) 3rd boat to follow that process and achieve that pinnacle ….. so rules and time were against them.   Against a now finely honed Italian team, coupled with a more experienced match-racer at the helm, they were finally outclassed.     A good part of sailing a large boat on foils, is clearly having VERY smooth maneuvers and the Italians are silky smooth right now.

So now, how about this final battle with the defenders … New Zealand ?

Personally, not being able to see the boats alongside each other, I don’t see a noticeable difference in sails or handling between the final two boats.  But there are visual differences in the boats and foils, and I believe these will show performance differences in the final series.    While Luna Rossa is clearly a very smooth boat with low water resistance, I sense that the NZ hull shape has been developed with more aerodynamic ability,  with the forward flare almost offering ‘added wings to the air’.  

 I Check out this photo where the artwork clearly shows off the forward flare. Once up and running at speed, this will help to carry just a little of their weight.    This ability can be paired with smaller foils, which of course makes sense at speed.   Foils (including sails) are designed to create lift, but this always come with attendant drag.    But the smaller the foil, the less the drag and we already saw that difference when the Italians sailed one day with a smaller jib but were faster.

But let’s look now at the main water foils … to which we need to factor-in weight.    Being as they have to meet ballast requirement of the rules,  if the foils are made small, they will likely need an added lead bulb to make up for the missing weight.   This we can see on the NZ Emirates boat.  I don’t see this bulb factoring into performance though

In my last AC75 update (Jan 1st 2021) I already commented that I was hoping the British boat would arrive with straighter foils, as theoretically, a flat foil parallel to the water surface must give the most lift per specific area. Any dihedral, either positive (like most planes) or negative (anhedral) as used by the other AC boats, must sacrifice a little lift relative to the speed.  I have to assume that the negative dihedral seen on all the challenger boats, offers some other benefit such as better control when turning perhaps.    But meanwhile, I like the straight foil that NZ has been sporting (see photo below left). But it’s remarkably smaller than the others though … some say even 25-30%!    Theoretically, that gives up a lot of potential lift, but if with the combined aero-lift from the hull mentioned above, and perhaps some nifty development of their flaps and foil section they can create enough lift to get the boat out, then their smaller foil size will pay off with less drag, and once flying at speed, we could see a significant top speed gain by NZ at the upper end of the wind spectrum.  (I’m going to predict a momentary speed peak of 55kts by NZ-Emirates that could best Luna Rossa by as much as 5kts).   Although momentary, this could prove significant on a windy day.    But only in winds of 15kts or more.

So can the other boats suddenly substitute their foils?   Well, only if they have been declared and measured as one of their 3 sets.   And there are time restrictions on that, as I understand their measurement certification needs to be filed perhaps as much as 10-14 days before the foil is used …which means that this cannot be a last moment decision.  

Finally, I start to see this epic competition more like a car race (and I did 12 years of that ;).  With cars, the fastest way around a track involves having a competitive top speed, but a race is more often won by those who manage the corners the best.   With a car, this means to fully evaluate just HOW fast one can navigate the corner on the best line and then switch down to this speed in the shortest possible time. This means great brakes as you want to keep your maximum speed until the very last moment.    But ’braking’ on an AC75 is not so easy !    And just how fast can each of these boats ‘make the corner’ or round the mark and stay vertical ?   Will the foil differences affect this?  And just how quickly can they depower and slow down to their ‘maximum cornering speed’, and then re-power up again ?    This is something that will be very interesting to watch for IMHO. And if the boats arrive at nearly the same moment at full tilt, could bring some exciting, though anxious, moments.

It’s also interesting to take a glance at this.  Here is an accidental touch-down that can cost 15 secs and that’s about 100m at a 12kt differential.  Appears the foil was lifted seconds too soon for the (wind) pressure available.

https://www.youtube.com/watch?v=NnOoZ9A9cJM       .     December Race 12 - check at the 27 min mark,

So how does this all add up?    I think the wind speed will have quite a say in this.  At the lower end, the large foils combined with the full, scow-like hull of Luna Rossa with its higher hydrodynamic lift, should have this boat out earlier, should they falter and drop down, compared to Emirates .… but once up and foiling, I see the advantage flowing to NZ as the wind picks up.   Sure, Luna Rossa will potentially have more lift with larger foils, but once the boat is flying, you do not need more lift ... what you need is less drag …and that edge would seem to go to NZ.

This drag is all about boat speed, and as far as a competition between these teams are concerned, this is a major aspect.   If you have superior boat speed you can recuperate from small errors but if you don’t, to win you will have to be very close in speed, and then also have the ability to out-maneuver and out-sail your competition.     We all saw the effect of superior boat speed with Luna Rossa’s dominance over UK’s Ineos.    There was nothing Ben Ainslee could do about this except win the start and that only happened twice.  With their choice of less grinders, I doubt they would win many tacking duels either, as they would soon run out of hydraulic power to quickly move the foils and adjust the sails     As I suspect NZ will show a speed advantage in all but the lowest winds, Luna Rossa will need to be very close in speed to give Jimmy Spithill a chance to potentially show his significant experience with true match racing at this level.

Now THAT would produce the sort of competition that sailors around the world are dying to see … an up-and-down tacking/gybing duel, where the slightly slower Luna, manages to out sail NZ to the finish line.    Will it happen?     We’ll have to wait and see.   But perhaps for a couple of races it will.  One thing for sure is that if we get into many tacking duels, those grinders will get the work-out of their lives, as the sail and foil trimmers on each boat demand immediate and maximum hydraulic power to try and get an edge.  Exciting times ahead!    With this crazy technology, I have to smile at that sail trimmer, who with a small, portable control station in his hands, can control around 20 functions of complex sail trim, and in minutes have those grinders  exhausted, as his little joystick-nudge suddenly demands several tons of mainsheet tension …..or whatever.   At his finger tips is mast rotation, outhauls for each of the twin-ply mainsails, travellers for main and jib, cunninghams, and a myriad of internal batten controls between those twin-ply mainsails, to most effectively power up and down.   But if foils need controlling at the same moment, there may very well not be enough hydraulic power for everything over critical periods of 20-30 sec periods when a massive amount of trimming is going on.   So, win or lose,  I have total respect for what these pioneers are attempting to do as teams.     What a changing race world indeed!

Brief thought on TACTICS:     As this final will see two of the top Match racers on the planet competing, these comments are just for those with less racing experience than I, and to help the non-racer understand a little of what we are likely to witness if things get close.   First, one-on-one Match Racing is unique in that you only have to beat one boat.   While that can sometimes happen in Fleet Racing for the final races of a Series, most of the time in Fleet Racing, you cannot afford  to fool with just one competitor as there are others on the course that will beat you while you are pre-occupied.   But with Match Racing, if you discover you have a slower top-speed but can find ways to also SLOW your adversary, you might still beat him.   Just for one example, if you find your foiler has a slower top speed potential due to your larger hi-lift foils causing more drag at speed, you might want to involve your competitor in a close maneuvering duel, causing both of you to drop off your foils.   If you can then get back up faster than your competitor, you could quickly see a 100m (or more) advantage gained.  In such a case, you may well have to cover your potentially faster adversary very closely though.

Clearly, the start has shown to be key, often with one boat immediately establishing a 100m lead.   Unless one side of the course is far more favorable for wind direction or force (‘pressure’ as they often call it), its typically a good move to try and cross the line at full speed at the RH side of the course, and get away to that side (on Port tack –  ie: wind on your port side).  When the boat reaches the course edge, you can tack on to Starboard so that now, at the critical first cross with your competitor, you have Right-of-Way and even if you are ½ length behind them, they will either have to lose speed by tacking early or go behind you, so that your ½ length will, for that moment, now become at least 1½ lengths ahead.   After that, the skip will have to decide if he has enough speed and wind pressure to build on that lead, or should he stay close to his adversary to cover his moves with his slower boat.  Unless one boat gets clear away with superior speed, it can be a game of cat-and-mouse and we could be treated to a rare chance of seeing the very best at this, play it out in full view.     I am sure the experts could write a whole book describing all the thoughts, actions, options and outcomes that are presented throughout every second of each race, so I can only try to get the adrenaline running with these brief examples.   Of course, if one boat senses they have a clear speed advantage, they would likely choose to stay well away from any conflicts with their competitor and then, this could become a parade to the finish ... a rather boring prospect, even at 30+kts.    But as these are two very professional and competitive teams, I am sure each would get more satisfaction from winning by 10 hard fought meters than by 1000.  I therefore remain optimistic for a great show.

But finally, if I am pressed to pick an overall winner …. I will have to go with The Defender, unless wind conditions are borderline low for the whole 2 weeks, for Luna Rossa to ‘strut its stuff’.     A new winner would bring the event to the Mediterranean for the first time and be very exciting .. and that would likely draw more European entries into the event.    

But meanwhile ...... MAY the BEST BOAT-TEAM WIN  ;)

Mike, Feb 2021


POST CUP WRAP UP                                          March 20th, 2021

Well, the best boat/team DID win and it worked out pretty much as predicted above, (even if I had privately given one more race to Luna Rossa ;).

What amazing boats though and as all teams were still learning what works best and how best to sail them, most sailors must be pleased that they have been chosen again for the next America's Cup ... in fact, they are presently saying for the next two !

As the last race finished, Aaron Young, Commodore of the Royal New Zealand Yacht Squadron was signing his acceptance of a Challenge from the Royal Yacht Squadron (UK) represented by their Chairman Bertie Bicket, that included an agreement on some basic but important governing rules, which are given below.    This makes the UK entry the official Challenger of Record this time around. This is great as it was this old club in Cowes, Isle of Wight, that hosted the first Cup challenge back in 1851.   Royalty often sailed there (HRH Prince Philip was a regular competitor there, often with Uffa Fox as his crew) and it was there that Queen Victoria witnessed the defeat of the British fleet by the state-of-the-art schooner 'America' and then famously asked 'so who is second?.  And, as if to predict the future of America's Cup Match Racing, the answer came "there is no second, your highness".

Personally, before the boats were packed away, I would have liked to see them pick a day with 15kts of wind or more and have a friendly drag race to see their real speed potential, plus any differences.     We did see a brief 4 knot advantage to NZ with a 15kt wind but I am confident it would be greater than that at the top end and we might have seen a rather terrifying 55 kts.   Ah well ... next time perhaps ;)

Here are the basic points agreed to by NZ and the UK ... with the underlines being mine to highlight the main points.

The official Protocol Governing the 37th AC will be published within eight months including the provisions outlined here:

• It has been agreed the AC75 Class shall remain the class of yacht for the next two America’s Cup cycles, and agreement to this is a condition of entry.

• The teams will be restricted to building only one new AC75 for the next event.

• A single Event Authority will be appointed to be responsible for the conduct of all racing and the management of commercial activities relating to the 37th AC.

• The Defender and the Challenger of Record will be investigating and agreeing to a meaningful package of campaign cost reduction measures, including measures to attract a higher number of Challengers and to assist with the establishment of new teams.

• A new Crew Nationality Rule will require 100% of the race crew for each competitor to either be a passport holder of the country of the team’s yacht club as at March 19 2021, or, to have been physically present in that country (or, acting on behalf of such yacht club in Auckland for the 36th AC event) for two of the previous three years prior to March 18, 2021.      As an exception to this requirement, there will be a discretionary provision allowing a quota of non-nationals on the race crew for competitors from “Emerging Nations”.

• There are a number of different options but it is intended that the Venue for the Match will be determined within six months and the dates of racing announced in the Protocol, if not before.


Previous postings on these boats with some design data and earlier updates,

can be found here under Special Articles


Note: Mike Waters has no direct connection to the America's Cup organizers or competitors. While technical views may be those of the writer, the data generally comes from official releases or openly published reports. While info has been reasonably researched and believed to be correct, there can be no guarantee of absolute accuracy. His opinions are purely personal ones covering his assessment of the situation based on information currently available. Photos are mostly screenshots from publicaly available videos . with thanks from all.