Inside INEOS' Foils : the most complex foils that you WON'T see in the Cup

Flap actuation is one of the most closely guarded secrets of the 36th America's Cup. We use our best internet sleuthing skills to speculate about the inner workings of the various foil systems.
Check out our previous videos reviewing Americas Cup foil design:
America's Cup Foil Problem and the ETNZ Rule Loophole: • America's Cup Foil Pro...
T or Y, Straight or Anhedral: • Whose Foils are Fastes...
Bulb or Blended Wing: • Was American Magic's b...
Foil area: • America's Cup Foils: D...
Fore- aft balance: • AC75 Pitch Instability...
#AmericasCup #MozzySails

[@VoxyGon]

Its wild how much variation there is between the teams with foil design. Great analysis, thanks!

[@vanislerider7311]

Exploitation of the rules is what competition is all about at this level. They are still regulated by rules but these areas have been purposely left open to open the design capabilities of the designers. This is where innovation earns its' keep.

[@markdawson8583]

Exactly, this is the Americas Cup, if you want to keep everyone within the 'intent' of the rules watch one design racing.

[@reetspetit]

Ever it was thus!!

[@TenaciousCovers]

Brilliant sleuthing and more great insights. Fascinating stuff. Thanks for putting the time into these videos. More please 👍🏽

[@simonpuxley7374]

Keep at it. Great insights and we love the tech!! Full of admiration. Thank you.

[@alienlifeformresearch2280]

This channel rocks. It epitomises the great Olin Stephens summation, on his 92nd birthday, of his life's single deepest insight into sailing design, research and development ..."everything is connected to everything else.... maybe even in different ways"

[@brysenelliott2527]

i realize it is kinda randomly asking but do anybody know of a good site to stream newly released movies online ?

[@callenjulian9415]

@Brysen Elliott flixportal :D

[@brysenelliott2527]

@Callen Julian thanks, I signed up and it seems like they got a lot of movies there =) Appreciate it!

[@callenjulian9415]

@Brysen Elliott Glad I could help :D

[@xDarksideLowx]

fantastic content and very insightful, thank you for making this so accessible

[@AnttiBrax]

The "curved rail" design makes so much sense... Thanks for explaining.

[@seanricketts941]

This video is excellent. Great insights to where teams are working around the rules

[@santiagobenites]

Excellent content once again! These boats are technically fascinating, and I've been learning a lot. Thank you.

[@bernardmoore8966]

amazing analysis - makes the races so much more interesting :)

[@timball885]

Thank you for all your effort, i really am addicted and it’s adding to the whole cup experience, roll on next weekend!

[@davidbrinkman2768]

On an aircraft flap the initial extension movement of the flap is aft before then going down. The first flap setting is used for long runways where the low speed lift isn't so critical but drag is, and the second and further settings increases the lift of the wing for shorter runways (I could go into more details but it isn't relevant). If that can be replicated within the rules, the initial extension would move the centre of lift aft without a huge increase in drag so it could be possible that you could control the pitch of the boat by continually moving the flap small amounts with greater flap extension for increasing lift during “take off” during tacking and gybing.

[@jons6125]

Best bit of the foil series yet

[@FrontNine09]

Brilliant Mozzy, I think my whole extended family are watching these videos now. You should ensure you make a playlist out of these foil videos so people can go through one by one.

[@MozzySails]

I have a AC Analysis playlist on the channel, but it's quite a generic lump. I'll look at getting them in to series.

[@FrontNine09]

@@MozzySails yeah, just think it would make it easier for you to post on the AC FB page and get loads of views due to an end to end view of the foil systems

[@Supasarge]

@@FrontNine09 Good shout. Nothing like a bit of housekeeping to improve accessibility 😊 Not wishing to take anything away from the overall quality of these deep dive Cupcasts but it might be worth considering some kind of upfront disclaimer for the playlist .... This series is not presented as the ‘holy grail of expert analysis’ (you’re going to get some conclusions wrong here, right?) more an attempt by fans to cast a more detailed lens over some of the fascinating areas this Cup is serving up ... by bringing together some of the basics science of speed with decent quality informed research ... Why? Because you’ve sensed there’s a bunch of like minded fans out there with similar thirst for knowledge and analysis (desire to go deeper) but due to the secrecy which shrouds every syndicates’ designs until the Cup is over, what’s called for here is a blend of informed guesswork and speculation in near real time (whilst the competition’s still live) to make the spectacle all the more insatiable.

[@johntasker9588]

Other than the single pivot point on ETNZ very little is known about the complete system, perfect !

[@nathanaustin7485]

Best video so far! I got really excited the lads might have changed their clothes for the first time since it's been weeks but lockdown pajama's it is

[@jameslittlewood7663]

Nerd-core deep dives into AC tech. Good work guys. Keep ‘em coming. Hey you guys should do an alternative live audio commentary.

[@Mmmmericaaaa_USA]

Great Break Down and explanation 👍

[@dyrlegeatgmail]

Yet another great one from you guys! Thank you. There may be differences in the mechanical engineering capabilities supporting the different teams, and this may impact the ability to exploit the rules fully. Mechanical engineering depends on skill-sets developed over generations, and the UK has a long history of excellence in this field, on a par with Swiss watchmaking.

[@twodogs2076]

Love your work lads. The AC has always been a source of innovation, driving the need for teams to look for loopholes in design rules. Some solutions work some don’t. That’s part of the game

[@NeuralEngin33r]

The mechanical engineering is 50% of the reason I follow America's cup. Until now I was left guessing by myself due to the secrecy. Mozzy's analysis completes the picture for me such that I can fully experience the cup. Watching the races, Im always looking for how the engineering trade offs are impacting the race and how each team compensates. Thank you! Also, please analyze how the tail and underbelly of each boat affects its launch from thr water. American Magics was reminiscent of the step behind a seaplane's belly that helps reduce drag once planing. This tail shape may have allowed them to launch with less foil lift, allowed them to lift the tail with thr rudder, and allowed them to rotate sooner like an airplane taking off. They could then benefit from less foil drag. Also please discuss what types of electronics the rules allow for the flight, rudder, and trim computers. How much are the sailors inputs being processed before actuation of the surfaces? For example, is the wheel directly attached to thr rudder or can there be a computer in the loop running a control algorithm to smooth it out? Are they allowed model predictive flight control? It would be a real time simulation of boat flight physics which could improve performance and safety by predicting ahead a few seconds and modifying feedback to keep the foils in the water or limit turn radius and trim combinations to avoid rounding up and capsizing? And if tese advanced fly by wire controls are not allowed what are the implications for faibcompetition, safety and ultimae performance?

[@robocap4910]

Very very interesting, thank you Mozzy Sails. IMO, these are the most important AC aspect

[@matira1]

Love the content, truly amazes me. I may have missed in a previous post, but I'm sure with the 'T' shape of ETNZ's foils allows that extra 300mm of 'Keel' in the bottom part of their foil arm?? This surely gives them an upwind advantage to point higher? Cheers

[@jamesnield]

Best title ever!!!

[@charlottescott7150]

Nerdy sail engineering mixed with great puns. Who could ask for more?

[@MozzySails]

@@charlottescott7150 just giving the people what they want

[@GER308]

Was going to write that

Verry good findings, do You think you could do a similar analysis of the twin skin mainsail controls?

[@MozzySails]

Next on our list!

[@alexwilli5450]

Zl

[@richlatvala8143]

Great stuff! Thank you and keep it up!

[@zaphodify]

Grat effort, thanks as usual.

[@damientelle]

official AC’s Media should think to contract you for expert/technical analyze video ! main stream reportages/interview/race comments is one thing, but it seems they allways forget that such sports event has also fan looking for deeper expertises. We had the same issue in France with the Vendee globe......>1h of media stream per day.... 0% of weather/tactic/technical analyze ....

[@mhh1848]

mhnm

[@mhh1848]

opk.

[@mhh1848]

nmkjymhg n ggoo

[@aardvarkmindshank]

Nice work. Thanks.

[@user-nt9nd7xm5f]

awesome elucidation as ever! Rob ... flap exploitation Spithill...salivates, takes apple to teacher, Mr Murray

[@TheLDunn1]

Great insight analysis once again. Thank you, I found it really interesting.

[@Biguggy]

After listening to all your vary in depth discussions which Ive found fascinating to say the least, is it possible to state which shape foils are better as in the y shape t shape or w shape ? And will you be discussing the effect the windward foil has aerodynamically on drag ect?

[@chriswoods2647]

Would love to see you discuss the nuts and bolts of the actual mechanisms that do this. Where do the grinders store their energy, then EXACTLY how, on a nuts, bolts, battery, hydraulic line basis, etc. does that make something move. A mechanical diagram of the systems would be fascinating....foils, flaps, rams, outhaul, Cunningham, shrouds, backstay...

[@douglasbrinkman5937]

reminds me of all the neat linkages i dealt with in my Kinematics of Macheriny course long ago.

[@peterwor]

Another great video, love the nod to us mtb'ers and sailors...😂

[@kevintimothyshields]

So dang interesting!!! Super well done again, thanks for the illustrations! Is American Magic allowed to now talk about the internals of their systems (or would they) now that they are eliminated?

[@MozzySails]

I think there will be discussion within Cup circles. However, these designers make a living from being 'the ones who know'. Their job's are linked to the fact that there are only so many people who know the secrets. As a result it's only when the technology becomes totally outdate that we start to hear the inside story.

[@truegret7778]

They used Mercedes precisely to look for loopholes, just as the do in Formula 1. Interesting discussion and observations.

[@michaelhall7879]

Really interesting guys thanks

[@MozzySails]

Glad you enjoyed it

[@turvyjj9232]

Very interesting, thanks. Now I'm getting in a flap over Ineos legality...

[@UnkleSi]

Great sleuthing! 😁

[@francescopierre-nina9515]

Well said👍🏽

[@trevorparker8686]

Excellent.

[@peterbee8892]

Under high flap situation Eg trying to take off is it possible to pressurise a water boundary layer from within the top part of the foil to maintain lift.

[@gheckolock81]

My style hero!

[@PowerStudios1000]

So was the foil with external rotation from Ineos not being sailed? What is the one they are sailing?

[@ralphiewho]

I hope that you have a video on the actual mechanics of the flap motion. The pressure on the foils will be high and therefore the forces needed to control the flap will be high. Keeping the mechanism small is a real challange

[@AnttiBrax]

I don't think there is public video about it anywhere. They're like the wing keel designs of the 12mR era. "Put a dress on the boat before lifting it out of the water so that nobody sees your secret bits."

[@Jdcrouch1972]

Is the hydraulics being so close to the control surface and the complex pivot points the reason for the fine control INEOS seem to have on pitch and attitude or more a product of the grinders facing sideways bringing a closer control to the balance point of the boat picking up on yesterdays clip? I see Harry had on an IG Account the W's back on this week.....

[@bachgenb]

The scraped marks on American Magic's foil bulb are called witness marks in the engineering trade, I believe.

[@dmurphy1578]

Wow. A mockery. Bold statement.

[@MozzySails]

Rob likes to be bold

[@dmurphy1578]

@@MozzySails thanks for these. I know nothing about fluid dynamics it any of this. You guys break it down very well. The evolution of our graphics has helped a lot too.

[@cosmosutcliffe9160]

if you go to 23:15 on Prada Cup Round Robin 2 Race 2 you can see Luna Rosa's flaps moving when out of the water.

[@MozzySails]

got a link to the video?

[@sailor4529]

Great stuff. As to exploitation of the rules - how can you control that? At the leading edge of any 'regulated' human activity will be a challenge to the regulations. Viz Trump. Rules are a key driver of innovation and creativity - yes, counter-intuitive but a fact. Highly enjoyable and informative. Keep it up.

[@jonstaines2947]

Are the movements or hydraulics close looped at any point for fine control of surfaces or is that banned in the rules? Addicted to your insights by the way.

[@MozzySails]

All flap movement (except flex) must by by crew input on a control surface (button)

[@SilvanMarty]

But the video and your questions ate great!

[@gafrers]

The rules are being "F1ed" which is totally expected in a top form a competition, it might be not ideal. The good old "grey area" also called "it's doesn't specifically forbids that" or "It's not technically compulsory in that way" Loving the content; uniquely detailed, accurate, and insightful.

[@BruceHoult]

That's because Americas Cup and F1 are two of very few "design competition" (aka Formula) classes in world competition. That's what makes them *interesting* and different from all the dozens of one-design classes that try to find the best drivers or sailors. AC and F1 are trying to find the best engineering solution and then ideally any fool they put on the helm will win. If that fool is a world-class pilot of course. But if the engineers do their job right and the boat is fast enough it doesn't matter which of Barker, Spithill, Burling, Ainslie, Outteridge (sad to see him sitting out this time as he's great) you have driving. Just like almost anyone in the F1 field could be world champion in Hamilton's car.

[@gafrers]

@@BruceHoult Couldn't agree anymore, especially with the "almost" because some could manage to ruin a race in which they are racing alone.

[@inquirist3534]

All the teams' clever tweaks and work-arounds must make the measurer's job in the AC75 class a nightmare, to understand and analyse for compliance with the Class Rule

[@bobawatsit]

did I here you say on one of your previous videos on wing design, comparing the 2 last challengers and ETNZ " forget about ETNZ and move on to the real campaigns " or words to that affect ?

[@MozzySails]

Say what?

[@bobawatsit]

@@MozzySails what ? can't read .... simple question, ....yes or no,

[@MozzySails]

@@bobawatsit what's the question?

[@joblack3991]

Very very interesting design challenging and consideration about different solutions. But, in my opinion hydrodynamics is not identical to aerodynamics so not all already known in aerodynamic is transferring in hydrodynamic field.

[@sunnyc8900]

Wonderful details! It's a shame that there's no level playing field as a result of some teams bend the rules to bend their foils. While others play it straight.

[@Robinlarsson83]

To be fair, that's pretty much the spririt of the cup :) You stretch and bend the rules as far as you can, and as long as you don't break them (or get caught breaking the rules), it's all fair and well in my book. I can assure you that all the teams is doing that, if not in the foils, they are doing it elsewhere. Finding the best solutions within the rule is pretty much the point of the design game. Just look at ETNZ putting foils and fully flying their AC72 back in 2013 cup, in a rule that was written to try to make it impossible to fly on foils. Juan K was so sure that foils wouldn't work (he said something like A boat with foils will not win the cup) that Artemis ended up behind in foil development. In the last cup ETNZ managed to find a loophole that allowed them use bicycle style grinders and that likely played a big role in them winning :) It's the America's cup after all! :)

[@spikeypineapple552]

You're kidding? Americas Cup is a design challenge. Given a set of constaints, what's the best package you can put together? Examples: Wing sail, trimaran, bulb keel with winglets, leg powered grinders, carbon fibre, laminate sails, coffee grinders, laser distance measuring, GPS start line calculations, VMG calculations, foils. ALL of these things were designed around bending a rule. They arn't like 'oh they tried something different', they're all things that were explicitly banned in one way, but snuck in on a technicallity. Sailing today would be a lot more boring if they wernt constantly pushing the envelope.

[@AnttiBrax]

@@spikeypineapple552 I'm not sure if people understand that on any level of "box rule" racing the first thing a design team does is to find out what the rules *don't* explicitly forbid...

[@Robinlarsson83]

@@AnttiBrax exactly! If you don't do that, the other guys will and your chances to win gets reduced. A slower boat almost never wins, especially not at the level of America's Cup. As long as you don't actually break the rules, stretch and bend and explore the boundaries as much as you can! One design has it's advantages for sure, but it's not as interesting to watch :) The top teams usually win no matter what the rules are, and in development classes you atleast have the chance of an underdog finding a corner of the rule that the others did not, and win in some conditions. In a one design rule a team with lower budgets basically can't win, since they probably won't be able to spend as much cash on sailors and time on the water, unless the race regulates every thing very hard. It wasn't a surprise that Dongfeng won the last Volvo Ocean Race for example, they were clearly one of the top teams. ETNZ in the other hand has proven many times that they can get very far or even win without the biggest budget in the race, in very open development classes. And lastly, the AC is actually meant to be a design challenge, much more so than a sailing race, the sailing part is basically just to show which team built the best boat :) The last decades there has of course been a much bigger focus on the sailing itself, which is nice for us spectators :)

[@carledelberg8936]

Great video! I am not sure the "four flaps" assumption is correct though. At 8.20 in th video, if you remove the bottom green dot, all the points are in the same line, and I could only see one external hinge (looking quickly). That could mean the whole flap is actually one piece, not flexibly joined.

[@tonysu8860]

But I think the ideo assumes, perhaps by a distinctive visual difference between inboard and outboard flaps that there is a different amount of rotation ... So although the pivot point might be the same, there are distinct different foil flaps which exert different pressures.

[@ianjudd2909]

Fascinating stuff and great research to backup your conclusions. At this rate one of the teams will employee you guys as their virtual spy team !!! 😀

[@davidlonesome6817]

The working of the mainsail analysis would be good todo.

[@timthurnham5654]

May I ask a question unrelated to the foil-controls, and I hope not too basic ... Do these boats gybe or tack on downwind legs? If the boat speed is above the wind speed, then their apparent wind direction will be forward of the beam. So, during a change in tack, will the bow pass through the apparent wind - not the stern - even on downwind legs?

[@MozzySails]

They still gybe. Although you're right, as they go through the gybe, the wind will feel like it is coming from in front. On board it will feel like the wind goes light and AWA will swing around the bow. However, it is still a gybe and still feels very different from a traditional tack as you are turning away from the apparent wind angle toward the leeward side of the boat and the entry to the turn is a bear away. This isn't just unique foiling boats, but plenty of high performance dinghies experience this (check out my channel for some skiff sailing which provides the same).

[@timthurnham5654]

@@MozzySails Many thanks for your answer to this question - and for your excellent videos, in general. My sailing experience is limited to traditional, displacement boats - and can only dream of speeds reached in new high-performance boats. This America's Cup is very exciting to watch, and a wonderful showcase for our sport.

[@SilvanMarty]

The rules says there have to bee one flap,or u can one side cut in four peaces?

[@fredherfst8148]

Fascinating..tx

[@mabryatpinnacol]

Love your commentary but have a question that I haven’t seen addressed. Ultimately everything these boats do comes down to boat speed and VMG. At the end of the day what are the limiting factors stopping these boats from routinely exceeding 50 knots? Is it primarily hydrodynamic drag on the foils or aerodynamic drag on the hull and sails? Would love to see you talk about this aspect... keep up the great work!

[@Niels4354]

It is cavitation of the foils which basically means the pressure differentials over the foil create local pressure drops where the pressure goes below water vapour pressure creating vapour bubbles over the foil which then looses its grip in the water. This occurs around 50 knots. To have a stable foil above 50 knots very different profiles are required (non-NACA profile) which are suboptimal below 50 knots...

[@derekstannett8477]

@@Niels4354 Hi Neil's, I am sure you are right and have seen similar statements. The cavitating presumably only occurs on the upper/low pressure surface, with high pressure side not impacted, so not sure what effect then comes into play to create increased drag and thus act as a limit on top speed. Can you expand?. Thanks.

[@mabryatpinnacol]

@@Niels4354 cav

[@mabryatpinnacol]

I’m familiar with cavitation from windsurfing. If the AC75 foils are starting to cavitate at the high end of the speed ranges we’re seeing them reach I would have guessed there to be more radical reaction from the boat with the sudden loss of lift on the foil and resulting loss of counterweight of righting momentum. It would be interesting if these foils have been tested to see when the cavitation really starts to occur - 45, 50, 55, 60 knots? T will be interesting to see as the series of races continue if the average boat speeds continue to increase...

[@derekstannett8477]

Did a bit more research on this and seems cavitation bubbles essentially increase thickness of foil which in turn increases drag. There were a couple of interesting videos from Vittorio D'Albertas, E4 and E25 on foil design and cavitation/ventilation. Would be interesting to see Vittorio and Pietro in discussion with Mozzy and co.

[@VentoRacing1]

Great show. Excellent discussion.

[@drdoolittle5724]

Is the weight on the flap same as the net weight of boat plus working load?

[@thebigmacd]

No, a significant portion of the boat's weight is supported by the fixed wings.

[@jameslippert3523]

I’m wondering why they would use hydraulics instead of jack screws for foil actuation. I would think jack screws could be used in a smaller mechanical package.

[@BrunoWiebelt]

wondering why they not use a pneumatic system like in the FESTO wings???

[@barrystevens2780]

Are there rules against having flaps essentially on the leading edge of the foils.?

[@peterreber7671]

I feel we are going down the path here. IMO INEOS' external hinges could never take the loads reliably. I agree that joining flaps with flexible material and claim that this makes it one flap is disenginious, to say it politely. The same goes for external pivot points. But basically anything complicated cannot take the load, IMO.

[@joshuamarkel43]

why is one foil capable of keeping the boat balanced front to back. why doesn;t the nose go down or up. is it a self cancelling system whereby the nose going down changes the angle of the foil to produce a moment that turns it back towards the level?

[@breakinghabits_II]

Why am I here? Ohhhh... that’s right...the title 🤣

[@hilldiver]

The latest Ineos video ("Moving Parts | Control Systems & Software Team Leader, Will Bakewell") has a brief underwater view around the 01:25 mark, but guessing it's not really anything helpful as it's been OK'd for release by their PR people!

[@MozzySails]

Well spotted, that's the outer part of the Y foil. The section with a point of rotation within the foil wing.

[@nialloftheninedevils]

ETNZ wrote the rules understanding how they could exploit them with their single flap. Its extremely naive to think it would be 'all fair' and the rules would be taken at face value. Just look a F1. These teams will exploit every loophole they can find. To do less will almost guarantee failure.

[@michaeldomican]

Nice sleuthing!

[@boatboy222]

We can assume you are correct with your analysis, wonder if Ben is laughing and thinking let them believe what they see and interpret!🤣

[@ukaszmaksymowicz4579]

I have a questions. I heard a rumor that ETNZ is not that much in love with Luna Rossa anymore and they are negotiating with INEOS to make them challenger of the record in case ETNZ wins. Why is that? what happened?

[@MozzySails]

I think Luna Rossa are very serious about winning the cup and at some point that causes friction between defender and challenger. I'm not sure ETNZ will feel any happier with INEOS next time rounds. These are always marriages of convenience!

[@ukaszmaksymowicz4579]

@@MozzySails Well, Sir Ben is also very serious, but he is committed to keep AC75 alive if he looses. I don't know where Luna Ross stands on this subject.

[@MrCruizydude]

INSIDE RITAS FLAPS, brings back memories 😛

[@cjprimata]

Like the insight but circumvent the rules all ways been the core on development?

[@rossatonic572]

Gentlemen..not related to this - Having watched the click video, plus listening to the wattage outputs suggested for the Grinders, are there any drug tests in AC. Havig looked at some of the guys smashing away, in the gy,m plus the incentives to do so, PED's such as anabolics and EPO would be undoubtedly tempting. Controversial, but...

[@MozzySails]

Yup, they're drug tested. AC sailors are added to the world sailing test pool... and given how few events sailing have had I reckon they'll be getting the bulk of the tests.

[@rossatonic572]

@@MozzySails nNteresting - Not WADA probably? I'll ask More PLates More Dates!

[@MozzySails]

@@rossatonic572 it will be wada complient as part of world sailing. Not sure which labs are doing testing though.

[@carbonarne675]

look at this video against the current one! crazy

[@MozzySails]

Setup has changed a little 😉

[@wezdog1]

W foils are usually called inverted gull wings

[@AliBFPV]

Bending the rules within the rules. That’s basically how f1 works.

[@dyrlegeatgmail]

I believe it is called evolution?

[@AliBFPV]

@@dyrlegeatgmail yep. exactly like Mercedes DAS this year.

[@Yairsuari]

Thanks again, super interesting I have a basic question regarding the AC-75. from a hydrodynamic perspective, the direction of the hull is formed by the line connecting the rudder and the foils (look at the image in the link below) yet the boat sails like a traditional sailboat (on the transom to bow direction) how does this work? www.dropbox.com/s/gdlzrxnetglzlbx/4Forum.png?dl=1

[@MozzySails]

the resultant force for the traditional sailboat you see in your diagram is not completely correct. Actually, all boats make leeway (slipping sideways). The amount of leeway is determined by lateral force from the sails and keel / centreboard shape. This leeway is required to get the correct angle of Attack on the keel / centreboard to produce lift. So, even traditional boats, despite having their keel and rudder aligned on the centreline, do not actually travel through the water with them in line with the direction of flow. So, you may consider the AC75 an extreme version of this. The rudder does no need to be in line with the main foil to turn the boat, it just need to be link physically via the hull so that changes in direction of the rudder cause 'yaw' on the vessel, which changes the AoA of the main foil and therefore direction of travel.

[@Yairsuari]

​@@MozzySails Thanks for your answer! I knew the question will be hard to explain. The question is not about the functioning of the rudder. There are many things which seems strange. For instance the forward force is upwing to the friction (foil) which creates a downwind moment. Also, I would expect the sail to be more sheeted in to be parallel to the rudder foil arm line. There are many things that seems to me are supposed to work differently.

[@MozzySails]

@@Yairsuari so your question is about the thrust (sails) being to windward of the hydro drag (foils) and the effects of this on helm balance?

[@Yairsuari]

@@MozzySails Yes

[@pietervandervyver516]

I come here for your graphics

[@MozzySails]

🤣

[@Avocettech]

Just spotted that since Rita came out of the shed, she now has four grinders each side!

[@andrewpease3688]

Team NZ foil arm is much more thinned out at the tip.

[@kauri7tane]

Sherlock. From Scotland Yard. On the case

[@SilvanMarty]

I said most importand its the doubble sail! How u twist and move it!

[@brianmarsh9754]

Great video. See the Ineos Team Video (Moving Parts) which admits 2 independent, symmetrical flaps. It pretty much confirms your sleuthing!! Great job

[@namnis1192]

Everyone knows, multiple moving surfaces tied together with dental floss and tin foil , makes it one.

[@emergingit]

The Americas Cup has always been about exploiting the rule.! It is a box rule, not one design so it's par the course. ETNZ have always been ingenious with their design thoughts so to beat them you to play the game and outthink them.

[@haitchd7659]

Did you really have to go with that video title 😅

[@rossatonic572]

Epic.

[@MozzySails]

I am so sorry, I just couldn't help myself. I know, I am a terrible person.

[@ecoworrier]

Oo-er missus 🤓 Loved the title.

[@beezergood]

Full marks, it’s made my year so far.

[@ecoworrier]

So if I understand correctly, you think that there is an internal mechanism which allows the flaps to grow in length and increase the wetted area. I guess that increases lift and performance. 🤔

[@goncalosousa3192]

Brilliant investigation! I’ve been struggling to understand why Ineos haven’t raced their W foils since these were the ones launched with the boat. I wonder if this an ace up their sleeves?

[@stevemagnuson7051]

I actually used to own a “Topper.” Didn’t know they had a “Worlds!”

[@alastairconn8793]

Because it's a World Sailing international class

[@stevemagnuson7051]

@@alastairconn8793 interesting....My mistake due to aging memory...I actually had an OD11 which was fiberglass, same designer, Ian Proctor. My understanding was the Topper was an exact duplicate of the fiberglass OD11, but rotomolded out of Polyethylene. Fun little boat, but very rare in California back in the late ‘70s. Lasers were built here by the 1000’s so that was the go to boat at the time.

[@stevenlarratt3638]

Its team Ineos not team Innuendos

[@user-vq3ou8ek7y]

Спасибо за то, что убрали мой комментарий :( Thanks for taking my comment out :(

[@MozzySails]

What comment? I don't delete any... KZbin auto filters some if you swear though

[@user-vq3ou8ek7y]

​@@MozzySails Мммммм! Извините, но что то пошло не так. Повторюсь. Механизация крыла самолета нужна для ..... УМЕНЬШЕНИЯ взлетной и посадочной скорости ! Нужны ли такие устройства АС75 ? :):):) Mmmmmm! Sorry, but something went wrong. I will repeat myself. Mechanization of the aircraft wing is needed to ..... REDUCE the takeoff and landing speed! Do you need such AC75 devices? :) :) :)

[@fedup3449]

Sorry but did your really name this video "Inside Ritas Flaps?

[@MozzySails]

I have no idea what you could find funny about that 🤭😇

[@chrisauld7630]

Enough smutty innuendo in the title to make you go ewwww. More than enough tech geek-outery to make you go ahhhh. Look for Luna Rosa to go for the red card if Rita gets her 4-flapper foils out for the Prada Cup finals.