Luna Rossa exposes Team New Zealand's costly design choice

[@MozzySails]

Shout out to Planet Sail who allowed me to use their interview with Jimmy. Go give Matt's video some love here: kzbin.info/www/bejne/gKGunI2FiZ50fJYsi=0oSKu__4UpvAIXAF

[@pauloalvesdesouza7911]

It's great having someone who's got the knowledge and the eye to bring us these insights. Big fan of your work.

[@jimwood9849]

Between you, Mozzy and Planet Sail, you both add another dimension to this AC campaign. Brilliant.

[@331Trevor]

Mozzy, I think it was more an error from the main and jib trimmers than a grand design flaw. When they made the initial bearaway the main trimmer smoked the sheet which was either because the jib wasn’t eased enough or just a mechanical error. From that moment the main trimmer was scrambling to get enough pressure in the mainsail which they did by moving the traveler up for some odd reason. That lack of main trim made the heading up and tack really expensive in terms of drag and that’s why they fell off the foils. More interesting is why the helm tacked when it was obviously going to be a total disaster? Lack of communication? Or just stubborn? That’s the thing that will be heated in the debriefing.

[@MozzySails]

To be fair that's not a bad theory either!

[@PeterBrand-ky8zw]

I like both Trevor and Tom’s theories but neither have addressed how NZ’s foil stalled at, what, 25 or 30 kt? to start the boat skidding. Was anything on board trimmed properly at that point? If not, lack of oil seems a more likely root cause than boat-wide brain fade.

[@mark_nz]

Yeah that's my pick - hectic start led to human error (only human!), possibly. Either way its a great show and in depth analysis is amazing mate.

[@connorjohnson4402]

@@PeterBrand-ky8zw He mentioned it in the video pretty much, its just due to all that yaw they had going at the time with the main all the way on the windward side like it was its just a big flat wall into the wind acting as a brake or effectively pushing the boat sideways. It seems like they got hit with dirty air and water at the wrong time, If you notice the moment they try and turn, their foils is directly in the wake of luna rossa and the boat yaws and they seem to be slipping a lot more then. I think they were a bit behind the boat and made the choice to tack quicker than they were ready and happened to be in wrong spot causing the foil to ventilate or just stall more than expected, once the other foil comes down when they are slipping sideways, its a huge amount of drag along with the rudder. Also looking back the first example he shows they had their upwind foil not down all the way, so could be some mix up in coordinating their turns as well or the lack of oil reserves, I forget if that also goes toward the foil controls as well or if those are separate and the trimming of the sails is what they have to build and maintain the pressure for.

[@tommyrq180]

I would love to see the cyclor wattage outputs on both boats throughout the start, much as they do in World Cup cycling. I don’t actually need to see EACH cyclor’s output (although that would be great), but seeing the total cyclor output throughout the start would be great. My sense is they are working really hard, perhaps 1K watts per cyclor or above, during the start phase due to more aggressive steering.

[@tullochgorum6323]

Best AC analysis on the web! If Mozzy is right, the key to beating ETNZ is to stay close and engage in old-style tacking battles, forcing them to drain their battery. On the other hand if they get into clear air their control of the mainsail might mean the simply out-drag you.

[@deerfootnz]

Not their battery. Their hydraulic accumulator

[@tullochgorum6323]

@@deerfootnz Strictly you're right - but you're also being pedantic. I've seen a lot of commentators and engineers describe the accumulator as a battery.

[@Coolcmsc]

@@deerfootnzAn accumulator is a battery and a battery is an accumulator. Nobody here things the Cyclors are generating electricity. You know that. Pedantry.

[@mcgilling]

as a team nz fan, hopefully the other teams don't watch Mozzy Sails videos, I swear he knows more than the other teams do

[@m1kalD]

I also found it interesting that the French had problems with their Rudder in the previous match in similar conditions. Which might point to design choices. I'm also curious whether there is a similar effect going on under the water with the foils as there is with the sails and the air up top? Especially when following the others foils + your own ...... The kiwis will get their heads around this. They will also very be glad its happened now rather than when it counts towards the Cup.

[@johnschieffelin3226]

Very clever and insightful analysis. I never would have picked up on that design compromise without you pointing it out. Thanks!

[@neonjupiterninsiandzeyafin82]

I couldn’t watch the AC without Mozzy’s contributions. Absolutely genius. Hey from Auckland New Zealand

[@johnmartin7158]

Hi fellow Aucklander, yes this is the go 2 channel.

[@hugofj866]

Brilliant considered insight as ever sir! Keep up the good work, you’re adding a fantastic extra layer of interest to AC37

[@mattclarke637]

I do a lot of windsurf foiling (I know it's not the same) you defiantly do feel a lot of wash even when following someone else. It is particularly hard to control in disturbed water if say you are in the wash off a bigger boat. Being that ETNZ were so close to LRPP in that manoeuvre and in the foil wash of LRPP it would have been really unsettling for their foils. It would be interesting to see that aggressive manoeuvre without the boat bing in disturbed water to see the difference.

[@GordonjSmith1]

Really interesting. The easy 'quick read' was the turbulence dumped on EtNZ by LRPP caused ETNZ to fall off their foils... - however in those conditions ETNZ would have been out of the turbulence quite quickly... which just makes the explanation here all the more interesting and plausible. ie When ETNZ were completing the tack to the right they were running out of accumulator energy after the pre-start manoeuvres, and thus control of the main. My thanks for this really interesting analysis and perspective - thought provoking.

[@OliverBatchelor]

Could the churned up water cause a problem? It seemed like the foils completely ventilated is that because they're dumped a load of white water from LR?

[@GordonjSmith1]

@@OliverBatchelor Well for sure it would be 'un-helpful', but the startling thing from my perspective was ETNZ's inability to get up on the foils in strong wind after their turn, which suggests to me that they were not able to trim the sails as they would wish to. But I am just an interested observer.

[@OliverBatchelor]

@@GordonjSmith1 Likewise, though do we have any reference how long it takes to get going for any other boat in these kind of conditions?

[@OliverBatchelor]

LR needed to take the nosedive in order to show us...

[@Pacsuper7]

What happened in that pre syart and the speed luna rossa showed on the first tacks got me sitting straight up. Either team New Zeeland are sand bagging or we have a memorable race comming up. Thanks for the analysis. I thoroughly enjoy hearing your insights into these VERY complex designs.

[@logandouglas8399]

Great analysis once again Mozzy. I was think it all started a bit earlier for us, TNZ. As LR were looking to come under us and we beared away, we did a half jib, and you can see the traveler come across to stb and it didn't come down at all for the rest of the start. We were in a good position to push LR up as they powered to the line but we couldn't get our speed up possibly due to the traveler being to stb. Possibly a trimming error not realising the position of the traveller, then trying to power up by pulling it on even more? which effectively stalled the sail. Then we got behind and compromised and it all got a bit much for the team, cyclors and sailors. Then as Mozzy says we ran out of juice and tried to do too much to get out.

[@profiskipinternational4402]

Awesome analysis. A joy to follow your details and thoughts about. Indeed, I had wondered yesterday, as it looked like that LR pressed the pedal to the metal accelerating tremendously to avoid the overlapping at the start line ... Many tks for your energy and investing the time for such precise observation. :-)

[@nicolasgoyard7998]

Coming from an IQFoil perspective, I am at first a bit surprised by the oversheeting in itself… I totally get that sheeting in the main sail loads the back of the boat which should be great to turn the boat upwind… However, it also loads the foils more increasing the leeway. On an IQFoil (which is an absolutely different contraption), for all roundings or luff actions, we previously deload the sail in order to reduce the stress on the gear and help turning and then once most of the turning is done, we sheet in. Otherwise there is a big risk of loosing the front wing and/or the back wing. In that case, it seems like TNZ overloaded the back wing and the front wing in shaky water from LR. Maybe canting the foil more and loading less the sail during the luff could have resulted in a lower risk of ventilation ? I know the two contraptions are really different, just sharing my thoughts

[@MozzySails]

Thanks for sharing Nicolas, I take seriiusly the view of any foiling olympian no matter if there are differences in craft!

[@connorjohnson4402]

Yea no experiencce with foiling either but you could be right they might've also hit some of the dirty air but if you notice the moment they seem to start to turn their foil looks to be directly in the wake from Lunna rossa and that's when they appear to start slipping the most, But it kinda appeared they weren't entirely coordinated and ready to tack or they dropped the upwind foil late or part way into turning maybe they didn't expect that slipping nearly as much as they were . During the first example as well they don't seem to have the upwind foil all the way down in the water. Id think you'd want the other foil down before you start into loading up the boat to turn cause putting it down when your already slipping sideways seems like its just throwing in a huge brake in the water.

[@weatheranddarkness]

@@connorjohnson4402 all the teams have at points been starting turns before their new foil is in the water. It appears to be a strong means of maintaining speed through a tack or gybe. But it also makes it that much more important that it starts generating lift soon because you want to lean on it to bring up the old board sooner than later. So I'm not surprised they didn't drop it earlier. I think one thing worth noting is that NZ's excess trim was probably also due to being in the gas off LR's sail, turbulent air requires more angle to get the same reaction force out of. It seems plausible to me that if LR hadn't had their own rudder ventilation then there may have been enough bite left in the water for completing the maneuver without falling off the foils. They may have been out of juice to trim for a little longer and would have taken a loss anyway, but they wouldn't have had to build from scratch.

[@randymcmeekin1955]

Brilliant analysis. I watched the race and missed all of this, just chalked it up to a down speed tack….Love this channel.

[@JonasWallinder]

Fantastic video again, being able to connect the dots really brings out the best in the competition.

[@ardernz]

Great insights and commentary for those of us without a lot of sailing and tech knowledge. Thanks!

[@hippodackl1521]

superbe video, great to listen to you and learn about these intricacies that are completely invisible to an ordinary eye.

[@1rudderbum]

Thanks for your insight and analysis , it helps to understand strategies and trimming techniques on these new designs / foilers.

[@alan4481]

Incredible analysis - thanks for drawing us into the detail with such clear exploration…

[@AliMasters-te7ez]

Great analysis as always Mozzy! From an Iqfoil windsurfer perspective, Luna Rossa’s round up looks perfect 🚀 Like some of the very top IQ’s they are maximising there acceleration pre start, looking to round up at close to max speed. As a result they can release main sheet tension & rudder load - doing the majority of the round up on the front leeward foil and use negative leeway + (Cant) to pivot the boat up to & beyond the upwind angle. Lots of lower end Leech tension & only twist in the top half of the rig may allow them to then sit on that high angle and stabilise the boat before getting into there upwind moding! Impressive stuff and shows the importance of time on any foil & influence of Olympic windsurfer Mattia Camboni as a cyclor for LR. Probably a mile off in this interpretation but it’s always nice when it’s relatable😅 Maybe limitations of this approach when following into the start but let’s see how bigger lane they can carve out!

[@BRMCaptChaos]

I added similar, any windsurfer who has spun the fin/foil out coming up can feel this on their back foot whilst cutting some interesting body shapes 😂 Got to unload the leach, get the centre of effort forward. Get the foil to bite and then ease the main on.

[@jonathanwilsonnz]

Clutching mozzie - I think it may well be a good assessment - that ETNZ will now be aware of & able to avoid the specific combination of scenarios in high wind

[@luposf]

Great analisys! This is my most favorite sail channel in english language 😊

[@markfisch1396]

Excellent analysis! You just made the cup more interesting, thanks!

[@brunoriva6203]

Hello Mozzy, it’s Bruno, i met you and the boys in Barcelona on Saturday the 24th near the Alinghi base. Very interesting analisys thank you, i was shocked when i saw that out of control tack from ETNZ, it was then a flawless race but LRPP until the Lightning strike.. what a race! Keep it up mate

[@MozzySails]

Hey Bruno, nice to meet you briefly!

[@ger5989]

Grand Dalton said in a interview: you have to set-up for a specific wind range and then you need some luck. There foil choice combined with the dynamic but energie intensive mainsheet system they are set-up for light wind. I think you right on the money. great stuff always combining the numbers with design a love it

[@polobat1]

Great insight and cut short enough to keep our attention! Very useful

[@MozzySails]

Glad you enjoyed it!

[@Spartan902]

The biggest lesson from that is don't tack in the wake of another boat. Cheers Mozzy! Spot on mate.🍻🇦🇺

[@zinny01]

Didn’t they learn that from Bermuda

[@Spartan902]

@@zinny01 I didn't see that cup series mate so I don't know what happened. I was out at sea on a trap fishing trawler north of Darwin NT, Australia doing 3-4 week stints depending on the fishing.

[@linx8171]

In love with your analysis....as always

[@simoncable8352]

Love the analysis. Thank you mozzy.

[@zaphodify]

Great drill down Mozzy!!! It seems poor cyclors are going to be the underrated stars on this cup.

[@stuarth43]

sailed in NZ since 13 years old, only just stsrted following foiling great observations, I am subscribed, nice to see Prada go

[@martinfloreseudal5265]

Excellent! best video analysis I've seen so far on the net!

[@Penguinracer]

Interesting observations. My thoughts are that ETNZ's boat is optimised for the expected lighter wind conditions of mid-October onwards & that they're still using re-cut old sails and it has been widely accepted that there's probably significant gains to be made from sail development. I think the spin-out was probably from a combination of factors - turbulence from LR's foils increasing the stall speed of ETNZ's foils and as you say, possibly low oil resulting in a poorly trimmed main and a rushed manoeuvre.

[@bwtcf]

Outstanding video mate. One of your best. No one else is presenting this level of analysis. I agree with your observations overall, and I do think the oil appetite of the twin mainsheet system is a massive factor in this. Jimmy's observation that Prada had emptied their accumulator (assuming he is telling the truth, of course), coupled with the wide open head of the main leading into the skid tack is irrefutable. However, looking at earlier races Team NZ had used the "bear-away, turn up, and glide VERY high" manouvre to defend the boat-lay before - See for example Day 4 Race 15 NYYC American Magic vs. Emirates Team New Zealand - Full Race 01/09/2024. T-52sec to T-45sec; and especially Yes, that WAS less extreme, there was another example (which I can't find at the moment) which was more similar to vs. Prada. I think the high traveller after the round up is both (a) a result of the oil hungry-ness of the twin mainsheet system AND (b) a technique they have consciously chosen & developed to allow a higher angle of exit to manouvres to close the gauge. When executed well it allows "better/tighter" manourvering in the pre-start, and can be used to catch an opponent out of position. There is no doubt that both ETNZ and Orient Racing appear to have a very powerful high mode, and can stay on the foils at a lower speed (17.5 knots and above) than other teams' lower ends. BUT, I think Emirates Team NZ will need to manage their commitment to high oil draining encounters and the challenger(s) will be aware of this and try to exploit it.

[@Jamespaintsplastic]

Great perspective. As an engineer, i find this deep tech talk fascinating! I am also interested in race car aero, inios have a lot of very interesting features when viewed from different angles!

[@panter82]

Yes and also Alinghi. I think they both collaborated with F1 teams, you can see that in the design of both Ineos and Alinghi

[@josh-a-roo1818]

Great video bro! Have a beautiful day

[@otuamab]

Fantastic analysys and insight !

[@normanholleman4835]

Thanks!

[@mcslashvideos]

You got an eye, man, thanks.

[@charlestoast4051]

Great analysis, it makes a lot of sense, and offers hope to the other teams!

[@andreat768]

Brilliant analysis, unmissable as always! Dai ragazzi andiamo!

[@SuperReasonable]

I’m pretty sure you are correct. We all know what it’s like to have the main strapped to windward with not enough leach line tension, the helm stalled out and the boat still going sideways, not heading up to windward. With these yachts it has to be caused by a lack of oil because rig changes are instantaneous - as long as there’s oil in the system. Your theory that the twin main sheets are very power hungry further proves the point. However, the winds in Barcelona tend to decrease as the Autumn progresses and the twin skin control will be very effective in lighter airs. I’m sure the Kiwi’s have optimised their design for the expected lighter winds as they start the defence races.

[@BRMCaptChaos]

On the contrary, I think they had too much leach tension (traveller too high) leading to a slab of main overpowering the foil. The actual leach tension is almost irrelevant, the centre of pressure is rear.

[@urbansailing]

Another stellar video by Mozzy! Incredibly high quality insight. I would also add, that together with what was mentioned in the video, the YAW statistic is a very interesting one. I would love to see a graph of a side by side boat when sailing. I would guess getting the AoA of the tip of foil shaft is something that is not exactly the same. Along with difference in shape of the fairing it gives another (although more insignificant) condition for the boats slipping laterally and refusing to turn in.

[@onlythesongsilike4856]

one of the best AC commentators! Mozzy should go on TV

[@phillipchan9125]

That's great analysis! I think you're on the right track with the main sheet system that ETNZ have developed needing more oil. Makes perfect sense. Hopefully they can find a way to counter this before the cup matches begin.

[@bertjilk3456]

Or, hopefully NOT, depending on your point-of-view 😂

[@ArchStanto]

Amazing video, the details of the trimming the sails are super interesting.

[@kieronmccann5793]

This is excellent analysis, thanks for this. I think the sheet controller is interesting and you may be right when it comes to intensive tacking or jibing, but in this particular case I think it was probably mainly down to poor trimming as you describe at the start. Thanks again for such detailed analysis.

[@rexprangnell6815]

The kiwis are not dumb ,they have been sailing for years andi think they know what is needed presumably the design was for expected lower winds in time of racing but i have never seen an A better review

[@clemdevine8828]

Best Am Cup channel!

[@marianoparada8408]

Just seen the review, quite informative as usual. Another factor not mentioned, is that both TNZ and Luna Rossa chosen to have the bulb above water, so their underwater has less volume. But out of both, Luna Rossa’s boot is significantly bigger than the one on TNZ. Think tnz will have greater overall speed, but will suffer more in chop or manouvres.

[@mtb5778]

Very detailed analysis. Thank-you. I was confused why they came off the foils.

[@KiwiBro8]

I'm now on the edge of my chair next time a boat pulls in front of ETNZ! Great content as usual, cheers mate!

[@nickleach3570]

Great analysis, I think what we don't know is the new sails ETNZ will have, I am sure we are not seeing the full ETNZ kit yet, its going to be interesting to see them training over the next few weeks, if we can spot changes.

[@GBH001]

This video aged well Mozzy!!

[@whereistheedge]

FASCINATING INSIGHT ! Thanks4THAT !!!!

[@solinvictus1234]

Persico, the Italian Company that built Luna Rossa, did an amazing job.

[@extremathule982]

👍👍👍

[@paulkennedy9759]

Tks again, I am always smarter after watching your segments, this one was a corker. Love Planet Sail, shout out to the 5 min warning show, may they never keep in in 5 min's.

[@jon1005]

I listened to this video and thought, Making a mountain out of a molehill. They made some errors in the prestart. thats it.

[@johnmartin7158]

lol, agree totally. Wonder if there is racing NZ time 12 : 10 am or are they taking another day off.

[@jon1005]

@@johnmartin7158 Hopefully midnight. was good to get some sleep though lol

[@JamesWard-o8r]

Brilliant analysis, thanks

[@federicocordioli7254]

Mate, i think you're onto something here!!! 👏👏👏

[@gillima20]

Great analysis thanks. Would be great if we could see other clips where this has happened to ETNZ or OE to confirm it. If its a lack of power I guess it would only happen in periods of frequent manoeuvres so most likely at the start.

[@nicholaycalhoun1681]

i always assumed that there was a third "mainsheet" further under the deck that did the coarse tune, and a bypass valve circuit between the two mainsheets we see that would allow them to mimic the older single mainsheet systems and revert to a less power hungry trim mode if they needed. apparently that isnt something that they have. great video mozzy!

[@devolution000]

Interesting, perhaps they could parallel the two main skins together for the prestarts to overcome the deficiency (in this part of the race), and then seperate them into independent systems again for the remainder of the race.

[@nicholaycalhoun1681]

yea, a few valves and hoses would seem to make it possible but im no hydraulics engineering

[@Gottenhimfella]

@@devolution000 or they could have a cam system to bias the location of the mounting end of the cylinders according to traveler position, to provide a sort of "default" differential between skins which did not require make-up oil during a standard tack or gybe. Then use the separate cylinders to finesse the individual outhaul tensions.

[@sebastiaanvanwijk5680]

Nothing escapes you.. awesome!

[@al.sargent]

Outstanding analysis! Thank you.

[@allanmegarry9143]

Excellent analysis

[@affe89]

Great video as allways! My analyse of what Jimmy mentions is that LR emptied their accumulator, which means they might have put all eggs in one basket, and if they were the ones to be forced to tack immediately they might have struggled as well. To confirm tour theory we would need to watch more prestarts with multiple rapid manouvers accross the fleet and I actually expect OE to be the ones to have the most problems having literally bought into the innovative ideas of ETNZ. One question that has arisen is why no team has tried to make 2-foil-sailing work for earlier takeoff in the light winds, they do it in some maneuvers but selldom to try to get up foiling at even lower speeds. Maybe for AC38 we need the penalty to be to get off the foils for X time/distance instead of dropping 75 m distance, forcing teams to make takeoff even more efficient.

[@AntiVaganza]

While I agree that the penalty for dropping off is larger than ideal, I would argue that with the brain power in these teams, they would definitely have simulated and tried to take off on two foils and concluded it's counter productive. They knew this to be a light air event and they certainly know how you can lose a race from dropping down. I am certain something this simple have been thought about, tested, tried and found not to work. Why it doesn't work, I don't know. It might be a drag penalty, I am not sure. There's also the possibly that you can make it work with a different design philosophy but if you went that route, you'd be hurting more often than not.

[@philliphoward5113]

Great analysis of team new Zealand's boat struggling to to turn im sure the team will be looking into this situation on a very derp dive to rectify before they enter the final to defend the cup, the boat has done tight turns before so there must be some other issues that brought this to light great work and also the interview from planet sail with Jimmy on his thoughts this was a race where they definitely dominated love the Italians turning up the wick on my team 😂

[@pauldennison9862]

Another great video and on the face of it very plausible. What we have come to know regarding ETNZ is that they have had the ability in the past 2 cups to have more 'oil' available that other teams, or a faster way to replenish, and they won't have given this away this time. In designing a main system that requires more 'oil' the question needs to be asked, 'what have ETNZ' changed elsewhere to allow this to happen? They also may have uncomplicated another part of their boat to achieve this. That's one of the words on the street. All Kiwis know that you don't take anything Jimmy Spithall has to say seriously when speaking about competitors, especially ETNZ, he is constantly playing mind games and sending people off down rabbit holes. It has been confirmed by Grant Dalton that the NZ boat is set up for expected wind conditions in October and they aren't chasing weather in early September. With expected light weather we have already seen ETNZs superior tacking performance in this light conditions which doesn't lend to the theory around the longer keel shape at the stern being an issue for turning the boat. I think ETNZ will be unconcerned about the situation in the last race and regardless of what Jimmy Spithall has said I think ETNZ is already living in his head where he doesn't want it. He knows he's up against it.

[@garyr1522]

Seriously good analysis

[@Paul_Thomas]

In the last cup NZ was always high on the traveler with a lot of action traveler vs main sheet. I am willing to bet they have some presets for beat, beam reach & DDW. The angle of the traveler with twin sheets can shape the sails more than just a main sheet. This was just bad sailing and the boat being setup for the wrong presets for the conditions.

[@MichaelSmith-go7xq]

Absolutely brilliant analysis.

[@highpointsights]

Since the 2013 Americas Cup I haven't paid much attention!! To be honest I lowered my level of attention during the years where the litigation was rampant! Having followed from Bus Mossbacher and the J boats (yeah I'm that old!!) That was a real change. I appreciate Mozzy Sails pointing out design elements I was completely ignorant of!!

[@babolgun]

Thank you Mozzy, very interesting indeed

[@Gefionius]

Best analysis out there. The official AC channel has good video but almost non-existent analysis.

[@NZbluesky]

Brilliant Analysis. Thank you.

[@isaactewheoro1197]

Great analysis Mozzy Sails , do not understand a lot about about sailing but trying to learn , no one seems to mention that TMNZ boat had taken a big fall of crane ,maybe damage from fall coming out , just a thought.

[@smilesandlaughsalot]

Greetings from New Zealand. Very interesting indeed! ETNZ will also learning a lot from these extra races - their strengths and their vulnerabilities. They'll be looking to keep their noses clean in the cup match pre-starts I reckon and then let Taihoro do her stuff. Ray Davies is such a great sailing mind and he'll sort them. But yes, staying on the foils is critical!

[@Si-jk4iy]

Great analysis. Like so much in life, it is never one element that determines success, rather an orchestrated combination of many subtle design choices, leading to an overall performance increase. But compromises will exist. The racing accelerates the learning and steepens the learning curve. ETNZ will have learned massively from this. The challengers too. The fact that the newly deployed arm was the side that cavitated along with the rudder suggests that foil deployment Timing was contributory. Did the newly immersed arm cause the rudder to ventilate by passing into its wake, or did the Rudder ventilate because the imbalance meant too much AOA was requested? The already immersed port side remained in flow despite being in LRPP's wake. The mainsail trim will be studied hard and a corresponding easing of the jib automatically as the traveller goes to windward in prestarts may also assist. Failing that, ETNZ will be upping their intake of Weetbix! Thanks for the thought provoking views.

[@powerskurf]

Great reporting on what must be the greatest technological racing machines in the world at the moment. Cetainly the largest things ripping around at those speeds. Love the cross to spithill and reference to the other excellent comentator. They are using alot of F1 tech as well I believe would be good to get a Laymans view comparing the two a F1 car VS a Boat just to illustrate the power and the speed.

[@8cervezas648]

Mozzy. You and I shared a table on the beach bar back in Vilanova last year on that stormy friday. The conditions yesterday were pretty similar!

[@MozzySails]

Very cool! Yes I remember. I've not seen rain like that many times before and I'm English!

[@hughesj74]

very interesting discovery there mate we will see in the days to come how much affect this will have

[@floodo1]

Glad you saw that very revealing clip of Spithill on PlanetSail. The other interesting tidbit was when he said they constantly have problems with the required race software provided, unlike in previous cups

[@plazma1215]

Got to be careful re this assumption. Only two competitors have got themselves penalised by crossing boundaries and start line (early) so far as I recall. The same two who are trying to blame the software (on one occasion with the 'must be cheating' innuendo). I don't buy it! I think it is just gamesmanship. When questioned about what Spithill had said, Grant Dalton replied something like, " all you have to do is win the cup, and you can write your own software".

[@floodo1]

@@plazma1215 well if Grant said it then

[@MikeB-lm6yw]

Love it! AC authority - let’s drop Stephen “no matter what size screen you’re watching on” McIvor, and get Mozzy on the commentary team!

[@moldfinger]

can we drop Shirley "really painting the picture" Robertson as well please?!

[@MikeB-lm6yw]

@@moldfinger - 😅 I like Shirley! But that’s probably from her podcast, so I’m biased.

[@MrVorobus]

Together with Ken Read, I miss his comments in this cup as well.

[@AntiVaganza]

You need a jock on the team. Someone to sell the vibe and not necessarily know the finer details. Otherwise, it's "just" sailing nerds only. Whether he's the right jock, I don't know but it's a small club and I guess someone thinks he deserves the job. What I still don't get is how often the live editor cuts away from what's important. I suspect the editor is less strong on racing knowledge than would be ideal. Time and time again, you see them choosing the "wrong" visuals for what's important right then and there. Like in the light races where they are just on the edge of dropping off of the foils in the gybes, they'd cut to an heli shot of a maneuever where what we need to see is if they make it through the gybe. That's for potential lead changing maneuvers and they decided we don't need to see that. Their highlights are a tad too simple, too. Maybe cuz they have to be so short. E.g. the highlight of the start in this race only cut to after LR had rolled over the top TNZ. That was a gutsy move, perhaps the most highly charged one of any start so far. I saw that and remembered thinking that perhaps I should actually really watch the series this time around. I don't have a dog in this game except being thrilled that TNZ was shown not to be invincible. I don't want anyone to walk away with it. Yes, the slide and coming off of the foils in the tack was important, but they should have shown that power charge, too. Not saying the editor has an easy job, I know they don't - just saying that despite all their fancy overlays, perhaps a very good sailor needs to help the editor a bit more. That said, it's early days and the media team can still very well learn on the job and peak soon enough. Also, not sure what data, what feeds and how big the screens are where the commentators sit? Because sometimes they do zone out a bit and don't comment until quite late. I would think they would have more info than we have?

[@robspinnler8047]

What a brilliant idea… Mozzy on the commentator team! Swap him in for the guy that’s sounds like a ten-year-old!!!

[@CapeBojeador]

Am I the only one thinking the Kiwis have nothing to lose and everything to gain at this stage by employing a little sandbagging?

[@mikethebreeze]

Be silly not to wouldn't they?

[@James_Hallam]

They have form

[@Diceloader]

Great observation but I’m not totally convinced. I think that TNZ drag the traveller to windward prior to tacking so the main is ready in position on in the next tack. I need to rewatch a few more tacks. Surely if rounding up was an issue just easing the jib would have spun the boat up quickly. I think they lost their rudder. They may have lost hydraulic pressure but some of the leeway could have been addressed by adjusting foil cant which I thought used batteries not hydraulics. Either way, I’d be surprised if TNZ don’t learn from this and will adapt by the Cup. Thanks for sharing!

[@beerbuffet1222]

Mozzy, luv your work & analysis 🍺🔥🍻

[@danjelowitsch]

Good stuff. Don’t forget though that ETNZ may very well be testing foils and might’ve not been in Sundays dress just yet. They can experiment around and fool the challengers into thinking there might be vulnerabilities to exploit only to then hit them when it counts.

[@iNav4Uchannel]

There is also an issue with the foils and the rudder in Luna Rossa's bubble trail. Water full of bubbles does not give the same lift and rudder control as plain water.

[@number1genoa]

The number of comments here vastly exceeds the official commentary channels, sailors are techo tragics, its great :-)

[@bradcole4693]

Good points. The slack main leech was odd, especially with the traveler all the way to weather. LR being fast enough to get over them set it up well. Tacking away was smart thing to do but the lack of steerage failed them, wonder if they have the smallest rudder?

[@SJ-dr4vb]

Interesting observation about the different jib vs mainsail dynamic between the two teams. I thought I saw Luna Rossa relieving tension to the jib prior to the race.

[@johnjkiwi7818]

Kia ora. Whatever designs flaws on Taihoro, they were overcome or didn't matter, because Emirates Team New Zealand comprehensively beat Britannia to retain the America's Cup.

[@BRMCaptChaos]

Windsurfing is such a good example of why you don’t force the foil under pressure on the leach, the spin out is predictable when centre of effort is rear countered only by a foil unable to cope. Got to unload the lateral force on the foil in this, put the centre of effort forward, re-establish the flow underwater. Exactly like LR did, eased main.

[@JustWillB]

On your last point about the hull above the rudder. Does that actually matter because in almost all situations they'll be turning with no hull in the water since they're on the foils, no?

[@Gottenhimfella]

I came here to make that same point. I imagine it's extended down like that to get the rudder bearing lower and hence less heavily loaded (less friction, less bending moment to snap the vertical foil element), and it's faired for low hydro drag when trying to foil, and low aero drag when foiling.

[@Paul-ik8fm]

Not sure this a boat issue I think more a preparation thing and I am sure if Mozzy knows this ETNZ will be on to it and sorting it out

[@jon1005]

Yeah agree, looked more like trim errors, i think he's reading into it too much here

[@markjones3425]

Great Critic and Analysis! Sharp eye!

[@brybotaylor5736]

You come up with stuff that is on another level. Mind you, going left up off the start on the penultimate race at Chi race week in my Solo didn’t work for me. DFL at the windward mark. I’ll follow you on KZbin only from nowon 😂

[@MozzySails]

Yeah, that was bad. Sorry. In my defence it does usually work, and had worked earlier in the week (I think the first or second day). On my Strava you can see a pretty massive right shift up the first beat. But after that I had my confidence knocked and worked the pilsey / stoker banks rather than risk east head and dunes area. www.strava.com/activities/12204927746

[@brybotaylor5736]

@@MozzySails Everyone seams to be tracking except me!. Can you recommend a smart watch that connects to Strava and I'll put it on my xmas list.?

[@MozzySails]

@@brybotaylor5736 I use a Garmin Fenix. Think it's a version 5, not sure what number they are on now. But it's respectable enough to wear in day to day use

[@peterwor]

Interesting, I definitely saw something weird there and I did see the clew of ETNZ's main to weather but I attributed the wipe out to dirty water from Luna Rosa. I hadn't considered an oil/power issue contributing to that but it makes some sense. The part that sticks out to me is, have we ever seen ETNZ's main especially the clrew of the main, in that position before when trying to either tack or head up?I've never seen that before, have I missed it?

[@RS-bn9rx]

Love the technical discussions.. as a non-engineer