Latest America's Cup boats explained

[@rayclark6596]

Best report I've seen. Why is it so hard for sailing channels to get it right. I'm here for the long-run now. Great job:

[@StefanoBrozzi]

I'm genuinely impressed by the quality of this report and by the narration by Matthew Sheahan.

[@mosca3289]

Great to see divergence in the designs.

[@paulmaheno496]

the larger skeg on the UK boat reminds me of the centre fin on the LMP Le Mans Race cars to help with turning or cornering

[@cjprimata]

Finally a report worth watch!

[@jamesdunn3387]

This was a great analysis and explanation of the lift/foil differences between teams.

[@alanyardley4832]

Andrew Sheehan is, in my opinion, the best and most knowledgeable yachting observer and commentator. I'm delighted to see him fronting Planet sail. Keep it up Andrew! Cheers

[@3Quils72]

Awesome video! The first time I came across the America's Cup was when I was a teenager. I've never sailed, owing to having a fear of deep waters, but I've always loved watching the races. I'll be watching this new race with much excitement.:)

[@jimthvac100]

This sailing technology is really something. Each year they come up with new amazing improvements.

[@aaronfranklin324]

It's kind of Amusing. I designed and built a 12 m crusing design in 1993, that had exactly the same curved hip pivoting ballasted fouls, but without the lifting foils. I rescued the NZ defence in late 1999 when the Auckland University Americas cup wind tunnel exploded into half a ton of fist sized chunks of Aluminium that were the twin ten ft Aussie four blade fans with composite resin transfer moulded, dual pressure bladder one piece shear web through the middle replacement blades that have tested every winning rig in Americas cup since. But the composite tech used for the yachts has still not caught up with that. And the rigs are slowly catching up with my Aero-elastic dual skin warpable landyacht rig design from 1986. Most of the expense in these boats is electronics and hydraulic hardware designed to convince everyone that they are needed. And make money for people already rich. However since at age sixteen in 1986 I was racing landyachts at 180kmph and won the senior men's NZ champs, And built that tech out of scrap parts and hand tools. I'm less than impressed. The last cup was a farce. We have no interest in NZ of going through the experience of having to hold back and intentionally throw races to avoid killing the sport again. It's become a bit like pro wrestling if you know what I mean. So. We gave the venue away. It's sad to see performance and innovation being held back to keep egos and fortunes of billionaires intact. It wouldn't be difficult to whip these yachts on all points if sail on a thousand dollar budget. But such open, unrestricted class racing is unlikely to ever occur until we stop kissing rich narcissistic sociopaths butts.

[@josez1]

Great job explaining each design. Loved the wing shape on the Italian boat.

[@HenryAyrestheoriginal]

Brilliant video. Great explanation of the engineering concepts that have shaped these boats.

[@garhull11]

HUman nature is weird. Relying on technology and science to build amazing boats, yet still superstitious about a bottle breaking

[@seiken_8940]

Gotta say that’s probably what makes us human, I don’t think we’d be here without that emotional and traditional part. But I like it, keeping those kind of traditions.

[@ron423]

Well - the boats are magic - perhaps there is magic in Champagne, too?

[@Make-Asylums-Great-Again]

More of a tradition than superstition.

[@ron423]

@@Make-Asylums-Great-Again Hair splitting! A tradition based on suspicion is still based on superstition - just in case there's anything in it.

[@ron423]

@@Make-Asylums-Great-Again A tradition based on superstition is still superstition - just in case!

[@garrysarre8744]

Very interesting brief insight into the aero and hydrodynamics of the different hulls designs

[@thomaselliott573]

they are not hulls, they are more like aeronautical misfits

[@pbnn735]

Great video as usual! Thank you!

[@henkondemand]

What gorgeous boats they are, truly magnificent.

[@TheSateef]

i remember when below the water line was a closely guarded secret

[@networkbike543]

They used to send down secretive divers to have a look.

[@Akira-cd8kf]

oh yh that was decades ago and funny how they don't care about it anymore

[@stefanzzz6778]

@@Akira-cd8kf but they do care about the foils and the internals now.

[@PetSKi67]

My take is, that thay only saw the rivalries boats at the start of the regatta. Obviously the design and building a boat shall remain top-secret stuff till the start of the regatta, but seeing what others have come up at the venue will probably have no, if any significance anymore. Damage is already done, if other team have come up with better design and no time to do other than get the best out the hull one have. That said, do they have new boat rule for each edition?

[@anthonyxuereb792]

drama ill never forget

[@thedude3251]

All of the boats are absolutely gorgeous, and the technology is simply amazing, wow!!!

[@BahnstormerUK]

Superb explanation, Prada looks incredible, almost organic .

[@keevee09]

Well reported and good footage. I cringe at the cost of this Sport of Kings but can't help but be impressed with the endeavour to succeed in one of the most technical of challenges. Bring it on!

[@weatheranddarkness]

My dream is that I'll be able to get a ticket on a trans atlantic sailing foiler one day instead of spending all that jet fuel it costs everytime I fly.

[@callumwyper]

The skeg is mainly for ease of takeoff as they were slipping sideways when trying to fly therefore losing speed. It basically is used as a center board.

[@skyak4493]

All the experts I trust also say that it is to close off air pressure release while minimizing drag in the event of contact with the water.

[@weatheranddarkness]

@@skyak4493 it's all of the above, but the balance is different for each program, hence the different interpretations.

[@jamesdunn3387]

@@weatheranddarkness, @Callum Wyper, and, @skyak are really onto something; takeoff surface tension, pressure release, minimizing drag during a splashdown, these are the trade offs

[@weatheranddarkness]

@@jamesdunn3387 I'm aware, i'm simply pointing out that the discourse about the aerodynamic aspect is also very relevant particularly considering the surface area to mass ratio of the hull.

[@Saltfly]

Hard to believe they get those kinds of speeds from the wind. It’s truly amazing.

[@Akira-cd8kf]

The only good video of the americas cup boats, great video

[@ron423]

Absolutely fascinating! As Barnes Wallace said - if it looks right, it will be right. The designers have found a new shape of beauty - and the paint-jobs - WOW!

[@vampireslayer1989]

Excellent explanation. Thanks!

[@LoanwordEggcorn]

Thanks for a great summary! The U.K. boat's bustle is like a longitudinally stepped hull. It may more cleanly reduce wetted area as the hull rises out of the water, and may also affect transverse (lateral) airflow under the hull. The sharp edges will also create vortices, which can be good or bad depending on how they're arranged and used.

[@stevenlarratt3638]

From a hydro vs aerodynamic point of view it will result in more parasitic drag, especially when flying, windage is key in reducing your drag factor, thus i think th euk boat will be last given the same sail area etc.

[@LoanwordEggcorn]

@@stevenlarratt3638 Yes, and that seems to be what's happening.

[@robertfairburn9979]

The skeg also provides lateral resistance. Which is also the same job a keel does.

[@Gottenhimfella]

Except that almost all of the time, it is (ideally) out of the water, and lateral resistance to the air is a vice, not a virtue, unless it can be slewed and cambered relative to the apparent wind. Which, of course, the rules (and practicality) do not allow.

[@TrulyUnfortunate]

It's amazing how far sail boats have come over the last 50 years. From mono hulls to foils....incredible!! It would be cool as hell to get a ride on one of these beasts!!!

[@missourimongoose8858]

The Australians were the first to the foil and because of that upset the Americans that had the longest winning streak in sports history

[@jeffcondell]

Excellent report- it will be very interesting to see what TNZ have come up with. On INEOS it will be very interesting to see how the extra drag works out before there is enough wind to get over that drag and start lifting the hull.

[@weatheranddarkness]

it should theoretically be lower drag especially since with relatively low speed the beam at waterline is that of the bustle and not of the whole hull, which works because the keel actually has a fair bit of buoyancy since it's so unconventionally thick.

[@michaelcooney7687]

Excellent videos.... keep em coming.. thanks..😊😎

[@jamesbyrd468]

Sorry, I remember the old twelve meter boats fondly. I was stationed at CG Base Honolulu in the mid 80's and watched Dennis Conner take out his two boats to practice off Waikiki and Diamond Head. Beautiful!

[@chrisbouris3699]

Prety anxious about the kiwi's boat. perfect analysis as always.

[@MrARH]

Just watching some footage of INEOS from 26 Oct. Looks as if they trim bow down for reach, then bow up for the gybe, and then trim back down Makes sense to maintain high pressure to windward and stop pressure leaking under the boat especially with keel-length skeg. Also the deck profile compared to water level changes at speed - slopes down at front and level at back - compared to at rest. Very interesting. Role of Trim Tabs on foils?

[@santos.l.halper1999]

Due to the AOA, the Skeg is useless. The aft profile however is more effective in terms of lift capabilities. But it will be negligible if the power input is less than the rest of the fleet.....

[@PhilbyFavourites]

I’ve tracked her through the Solent in my 265hp Nimbus. 28 knots vectoring in on her, ran level for 100 metres and she pulled away effortlessly in 12 knots of apparent wind. She truly bought a lump to my throat to see such beauty and engineering excellence. I admire your knowledge of the technicalities. I can remember when windsurfer design exploded and advanced in the very early 80’s this is that level multiplied exponentially. My old Laser (designed on a napkin I believe) always comfortably out sailed me. I look forward to a great battle and being English I also look forward to when “Britannia Rules the Waves.....”

[@LoanwordEggcorn]

@@PhilbyFavourites Otherworldly! Thanks for the anecdote! It is a wonder of engineering. (Keep in mind most of this is due to better simulation software and more powerful computers.)

[@baker2niner]

yes, it's not about hull drag, tracking or "lift". The hull should never be in the water. The bottom of the boat - skeg- is an aero endplate (like a winglet) of the sail. It looks like they trim to close the hull-water gap. Mind blown.

[@LoanwordEggcorn]

@@baker2niner Yes, I'd call the skeg more like a longitudinal wing fence. Both stop high pressure air flow from moving to low pressure areas or at least impede it. Pretty amazing regardless, and yes, the goal is for the hull to operate efficiently in the air most of the time and get off the water quickly. Performance can be gained in the transition off the water too, so the boats are designed to handle that differently, thus stepped hulls versus smooth, etc. Steps may optimize to quicker takeoff. Smooth may optimize to better performance in air (lower drag, but slower takeoff, so a slower transition from planing to flying).

[@ignasst]

Great coverage and good information. Thank you.

[@frombaerum]

Thank you so much for the explenation! Do you think its possible to make a similar explenation of apivia vs hugo boss`hull shape?

[@weatheranddarkness]

They're more similar than they are different. What the specific difference you're thinking of?

[@frombaerum]

@@weatheranddarkness yes the buttom of hugo boss and charal are more curved in the aft whereas apivia is flatter. so how does that inflict the boats performance while planing?

[@weatheranddarkness]

@@frombaerum there's this piece from Chevalier Tagalang: chevaliertaglang.blogspot.com/2019/12/imoca-2019-vplp-contre-guillaume-verdier.html He starts comparing them more directly further down the page (the google translate function on the page does a reasonable job). The flatter surface will plane more readily, but once you work in a common degree of list it confuses the issue as to which of the two boats actually has the flatter hull. It's not cut and dry however you look at it.

[@frombaerum]

@@weatheranddarkness wow thank you for the exelent link and very interesting remark you made there:D

[@raynic1173]

Isn't the Hugo Boss boat a planer as opposed to a hydrofoil?

[@panpenl7800]

1:04 what's the paint ceremony called? Is it on the mast?

[@scottrobinson7203]

Thanks Matt for a great overview. You are to AC tech which Politico is to political reporting - so refreshing to have the next level of detail explained

[@markbarber7839]

Thanks for the informative video!

[@MaJieMao]

40 years old and it amazes me how much the boats have changed in that time.

[@ron423]

I can more than double that, mate!

[@ron423]

@@benisrood Not so - it has introduced new skills into the art of sailing. You may prefer the art of flying spinnakers and so on and I have a lot of sympathy with that but the art is still there. Moreover it is clear that this new art has yet to be mastered.

[@bengaliinplatforms1268]

@@ron423 The difference is young people could start and race and understand the dynamics, the wind, and how to trim and fly spinnakers etc. Like football or whatever, even motorsport like open wheel racing.

[@ron423]

@@bengaliinplatforms1268

[@veryrare7647]

this is better than any video the official channel has produced

[@MilesCobbett]

I miss the days of America's Cup races in the 1970's. I loved those racing sailboat designs.

[@rayRay-pw6gz]

I was watching two 12 meters boat sailing just recently and they are beautiful but, sailing at 50 knots is breathtaking. I would love to see a replica of the resolute boat sailing .

[@desfrench825]

Below the water line yes when the Australian boat had the Warwick Collins winged keel which only one person managed to see the same keel I had on my boat Springclean 2

[@hevancleifrasson5923]

Nice use for the mcp yatch patented design, really a nice improvement

[@RobertAlexanderRM]

Very clear, beautifully explained.

[@gonger03]

the boat is supported on the buoyancy of a "Bustle"? what is the word that he says @8:03? Bustle? Vussel? Bosel? can anyone tell me how that word is spelled?

[@ne.grechna]

0:16 Ukrainian Antonov. Not russian. It's important.

[@РоманМарченко-м3ш]

Yeah, I don’t think they see the difference. But it hurts to be misnamed like that.

[@connormiccy]

@ i Tjidl likes do

[@piotrtrocki3842]

when Antonov was founded, Ukraine was part of Soviet Union commonly called Russia.

[@justbecause3187]

They are unique and beautiful aircraft, which both the Ukraine and Russia should be proud of. I know relations are difficult at the moment, I just hope that this legacy of cooperation and shared history isn't destroy.

[@hertsyk]

@@piotrtrocki3842 Until 1991, Ukraine was called the Ukrainian Soviet Socialist Republic, but not Russia.

[@shanemilner895]

Amazing design, gorgeous lines .. so quick 💥💥

[@ironmantwilliam]

Awesome Report and Breakdown on each boat cant wait for your report on Team NZ when they launch there 2nd boat tomorrow oh and you just gained another Subscriber for your work sir

[@johnburgess5534]

I get my dinghy 4 feet in the air BUT I have to upend it on to my car roof rack where it provides downforce. Great explanations of the science involved. Skippers will soon need a pilots licence!!!!

[@Englishkin]

A habor pilot's license? (An air "pilot" is really an air captain.).

[@ron423]

Get a bigger one! It will shade the driver and car from the sun and makes a marvellous foil if you are towing a caravan. It deflects the air over the 'van reducing drag while saving considerably on fuel consumption.

[@General_Crock]

It's providing lift when upended, actually. You might get airborne around 500 knots or so. Make sure your cinch buckles are solid first.

[@billgiles3261]

As someone trained in aerodynamics I think that the keel is not to stop the air ‘leakage’ underneath because of the difference of pressure on each side of the mainsail. Rather air flowing under the hull it would see an aerofoil shape and pull the hull down which is not what is needed.

[@captc0ck5lap60]

Got to 8 knots once and thought "ooo that's fast"

[@clayz1]

That’s like my 10 foot (3 meter) pram I had in my teens. It is exhilarating to accelerate when the wind hits you, even though the boat seldom went over 5 knots, and that only in one tack direction because the wooden mast was warped. Ah well.

[@TKRM2007]

Maximum speed of a displacement hull is 1.34 times the square root of the water line. That is why we are seeing planing hulls that are not restricted by that formula.

[@naterally2176]

when/where can i get an RC version of this. im at a loss of words when i see one arm up. gravity called in that day?

[@FedericoLucchi]

RC sailboats have been around awhile... never seen a foiling one though. My guess is, and I might be wrong, that it would be impossible to keep it balanced, just like you can't do an RC bike

[@zbeekerm]

Yeah, as a sailor and aerospace engineer I would say the Ineos UK design is an extreme gamble. It is a real eye sore BUT I would wager it might be more forgiving for takeoff and touch down. The skeg provides a buoyant & waterski planing effect. But the the corner effects and low speed increased wetted area (not to mention increased aerodynamic wetted area at high speeds) makes me think that this is quite a gamble and they are planning to win in maneuvers not straight line speed.

[@zbeekerm]

Also I’m not sure I buy the reduced induced drag due to the fence/blockage of the skeg, but that question can only be answered with wind tunnel and CFD data so I could be wrong. But the hull/deck should act as one heck of a winglet not to mention the fact that they don’t fly all that high out of the water and there’s already reduced velocity at the sail’s foot due to the atmospheric boundary layers velocity gradient. One heck of a gamble, but if they win I will have infinite respect for their design team. (I already know sir Ben is in the same class as Dean and Pete)

[@Tarapiotr]

@@zbeekerm I agree, I don't think the skeg is there for induced drag at takeoff speeds (15-18 kn?). I think (and I know rumors) for this boat someone from F1 Mercedes is involved... They know to deal with air better than the others I think. I'm very curious about this boat's performance, also in straight line.

[@AKaktusA]

maybe they just need a bit of additional lift in a tack and plan to touch down only onto the skeg for an easier relaunch

[@tomhollins5303]

Help run air along the hull into the bustle? I wonder how much of the bows are actually submerged when it is going at any sort of speed. There is one head on shot in the water: stationary but also unloaded, that implies the front of the skeg will be just clear. Its hard to tell the rocker on the skeg without a clear side shot when its up in the air. It certainly will get lift off the bottom to some degree. I'm not a sailor or an aerospace engineer, but I agree that their is something more going on.

[@RammYou2]

Just a question; when the racing sloops no longer have a hull up, when the masts are held into the wind with computers, when there are four programmers running the ship, do we have a race?

[@ChrisCoombes]

3:34 Why does the British boat have ‘Rita’ highlighted on the hull? - is that its nickname?

[@justinbrooks317]

Apparently all Ben Ainslie's boats (since 1992) have been called RITA

[@dp5475]

Goodness man, fine video and info, but how in the world do you supply us that that much of a tease and not end it with a good minute+ of high speed exhilaration, haha?

[@uberseehandel]

Just a small sub-edit - Antonov is Ukrainian rather than Russian. These days there is a difference! :-[] Looking at the photographs of Britannia, I was struck by how busy the hull shape is, I fear it is either genius or "it seemed like a good idea at the time".

[@PlanetSailOnline]

Good point Robin, noted

[@BlueMoonday19]

Pretty sure that plane is Ukrainian too? I also wonder if that strong hull shape is a bit too severe and all in design wise? The shape seems more defined and committed to a certain range of operation than the other challenges which indicates either a confidence in the modelling used or a bit of a gamble on what will work?

[@108hindu]

F1 has lots of very complex shapes and protuberances. “Busy” seems to work for them.

[@uberseehandel]

@@108hindu "works for F1." When I discuss design, F1 produces more bad examples than good ones. Take the F1 steering wheel, too complicated for the drivers to understand and even the race engineers have to look up the code sequences in a manual to relay them by radio to the driver.

[@108hindu]

@@uberseehandel A non aero part like a steering wheel isn’t the best example. The F1 aero bits do work and they are constantly being improved. There are many complicated interrelated things going on in an aero package. Some bike racers used to ignore aero developments but then they got tired of losing and now everyone is looking for the latest developments available to them. Did the brits get the aero right? Mercedes at Braxton did the design work and they have won the last 7 F1 titles in a row. My guess is they probably have done a reasonably good job. I’m American, rooting for the kiwi’s. I hope the brits screwed it up but they probably didn’t. If Luna Rosa wins that would be ok. Then the next cup will be in beautiful Italy. The kiwi’s will be pumped up to go bring it “back home”.

[@bushflyr7335]

@3:34 are those scupper drains or is it a blown hull?

[@LoanwordEggcorn]

Probably drains since they're small.

[@jonathanmears8600]

Believe skeg more likely to do with breaking surface tension from water as hull rises. Lot of surface area breaking at once on the flat bottom boats.

[@weatheranddarkness]

the Prada and American boats do mostly that, but with the extra area and planform of the UK the design has a significant aerodynamic effect as well, it also provides a narrow planing surface.

[@jonathanmears8600]

@@weatheranddarkness sure

[@weatheranddarkness]

@@jonathanmears8600 These boats are extremely light for their size

[@Gottenhimfella]

I thought that back at the beginning of this rule, but the Gen1 boats seem to break free relatively easily - more easily, I suspect, than even the teams expected or feared. Being able to configure the flaps for low AND high speed lift must make a lot of diff here. But the fact that the foil on these monos is far out to leeward from the contact patch with the water, in comparison with the leeward catamaran hull, means that lift-off on the monos only requires moment (with a relatively low reaction force down on the foil) rather than the direct and considerable upwards force which the lee hull of a cat requires. There is also, it is evident, much less retardation from touching the water than with the cats, which will (hopefully) encourage more tactical engagement boat-with-boat.

[@jazldazl9193]

@@weatheranddarkness think 7 or 8 tons. Alot of that in foils.

[@carisi2k11]

Now compare this to the almost single make boats from 4 years ago. 4 boats and what will be 4 amazing designs.

[@bricology]

The narrator is one of the best I have heard in sport. He sounds authoritative, dignified and personable.

[@kurtkrause7151]

Weird. Wild, Beautiful...Go-Time U.S.A. What a design, time to Dominate!!!⛵️

[@Maverick92NA]

Great video!

[@DialedN_07]

Superb content!

[@icleave]

Fantastic video, you earned a subscriber

[@jpsou76]

super cool these boats keep getting more Awesome...

[@julianharms4109]

Finally an answer to the reason for the skegs/ keels/ fins! I googled it earlier Matt, but you are the first to provide an explanation. Looking forward to more detail. Is it me? or is there more than a touch of International Moth hull in that shape...?

[@weatheranddarkness]

Definitely a bit!

[@169063]

I dont think it has anything to do with aerodynamics. Flat bottom boat has a huge draft, narrow shape enables them to get sooner from the water.

[@BluesAlmighty]

So the next evolution is moths with a skeg? 😁

[@weatheranddarkness]

@@BluesAlmighty maybe a crisp little keel like the sternward portion of the american boat, just for that last little bit of ease of release from the surface. The hulls are narrow enough, and there isn't really a good reason on a moth to sail close to the water, so no use for a minor planing surface like RB2. The AC75 boats have the capacity to cant their foil arms pretty wide allowing the belly of the boat to ride very close to the surface, maximizing righting moment, but at the same time reducing the wetted length of the foil arm. If you were to try and sail low on a moth you'd be dragging more of the vertical strut through the water slowing you back down. And you'd already be hiked out as far as you can with the sails full of wind so there's no RM benefit to going lower.

[@BluesAlmighty]

@weatheranddarkness Although my remark wasn't meant seriously, I do thank you for your extensive answer and explanation! Smiles on nautical miles!

[@tullochgorum6323]

Ineos are working with the Mercedes F1 team. Their aero skills are unmatched, so hopefully that radical design will give them an edge. Maybe this time - while I'm still on the planet??

[@MrMezmerized]

I wonder why they dropped the two-segmented rigid main sail of the previous edition. Those seemed to work excellently. Cost cutting? Too fast in combination with this design?

[@millicentsquirrelhole582]

Oh, yeah, folk will stay tuned especially with the insightful coverage from PS. One small question: 'Are those sleek off world craft really 'sail' boats or are they secret submersibles as well...?

[@richri8473]

How the Duke and Duchess of Cambridge are already preparing to be King and Queen www.telegraph.co.uk/royal-fam... Will they be a good King and Queen of England?

[@richgee7068]

The prime minister is publishing a #COVID Winter Plan, which will include tough new restrictions in England in December but a break of up to five days for Christmas. Read more 👉 news.sky.com/story/covid-19-g...

[@millicentsquirrelhole582]

@@richri8473 Yes, well, what if they aspire to being...King and Pope and BoJo's coiffure lackey? (s)?

[@katerinakemp5701]

@@richri8473 well hope they can handle it. We shall see eh cuz lol.

[@TomLeg]

How about replacing the skeg with an "under-sail" --- a skeg that can be adjusted

[@LooksInteractive]

That was really good

[@ChimeraActual]

Is "skeg" the now accepted name for that bit of boat below the canoe body, either full length or forward, on centerline ? To my my mind a skeg is a fin/protuberance near, or at, the stern that either supports the rudder or assists in directional stability. I would call it, perhaps, a keelson. As to its function, your guess is as good as anyone's at the moment; an aerodynamic endplate parallel to the sail plan. But the hull itself is already a pretty good end plate, and given its proximity to water I wonder if it isn't meant to release the hull from the water as it rises on the foils. Do you have more pics of the "bustle"? Good job all in all, though.

[@LoanwordEggcorn]

The hull is an endplate to the sails. The keel/skeg is a wing fence/end plate to the hull. Air flows under the hull once the hull is flying. The skeg blocks that air flow to keep more of it over the sails. Skeg is an ok name. It's also a modified keel.

[@ChimeraActual]

@Loanword Eggcorn I see your point, it's meant to seal the hull to the water until liftoff is complete. That suggests that there is relatively less pressure available when the hull is flying, interesting. I'd like to hear from one of the aerodynamicists, and perhaps see some smoke streamlines or a simulation. I still don't like "skeg", it's not placed where you would normally look for a skeg, nor does it function like a skeg. By your explanation, it's a fence. A "keel-fence"? Too awkward. A "Skence"? Or simply the "Seal"?

[@LoanwordEggcorn]

@@ChimeraActual It would be a hull fence or wing fence when the hull is flying and acting like a wing. Like a wing fence, its purpose may be to prevent/discourage wind from going under the hull laterally. Doing so would keep more air going over the sails instead, which would be desirable since the sails provide driving force. It is a skeg in the sense that it protects the hull from impacts with solid objects more than a keel is intended to. But yes, it is an unusual use of the word skeg. I might simply call it a long and shallow keel. That might be more traditional.

[@ChimeraActual]

@@LoanwordEggcorn I'm beginning to fall for "skence". We want to win the cup, hence the skence!

[@jazldazl9193]

keelson a structure running the length of a ship and fastening the timbers or plates of the floor to its keel.

[@camerontait8930]

add foils to the top of square sails. big advantage.

[@bowantoia8536]

I'm no expert so I'm asking, will the skeg on the UK entry create an upside-down sail effect. More surface area for the wind to catch and if so is that a good thing?

[@thomaselliott573]

naah. the boat itself will just effortlessly have a self-righting upside-down effect

[@bowantoia8536]

@@thomaselliott573 😀

[@thomaselliott573]

@@bowantoia8536 it is actually meant to enhance power and lift

[@bowantoia8536]

@@thomaselliott573 thanks for your reply. Yeah kind of get what you are saying but I was thinking high sided vans or trucks. Side on there is more surface area and the keel will catch wind just like the sail. Maybe I'm over thinking it lol or maybe there are compromises or maybe it assists. Looking forward to the racing though. ✌

[@thomaselliott573]

@@bowantoia8536 it is about separating the two sides of the boat. One side is supposed to have negative pressure and the other +ve pressure

[@crusty3260]

What are these boats called?

[@РусланГабдулов-ц7я]

0:13 Ukrainian. This type was created in Kyiv, USSR, specifically this aircraft belongs to the Ukrainian state transport company. Please, pay attention to the flag and colors of the livery

[@ne.grechna]

Exactly

[@deltagbeta]

Antonov is a Russian company.

[@РусланГабдулов-ц7я]

@@deltagbeta Wikipedia Antonov State Enterprise (Ukrainian: Державне підприємство "Антонов"),[2] formerly the Aeronautical Scientific-Technical Complex named Antonov (Antonov ASTC) (Ukrainian: Авіаційний науково-технічний комплекс імені Антонова, (АНТК ім. Антонова)), and earlier the Antonov Design Bureau, is a Ukrainian aircraft manufacturing and services company.

[@РусланГабдулов-ц7я]

@@deltagbeta www.antonov.com/en/contacts

[@deltagbeta]

@@РусланГабдулов-ц7я founded in Russia May 31, 1946, Novosibirsk, Russia

[@flecktrain]

Good explanations! Thx, btf*

[@u235u235u235]

no video of boat moving?

[@chrismetisse7248]

Bongo drums ! Frenzied Bongo drums ! Why can't we have Constant Frenzied Bongo drums , like all the other channels ? Are you some sort of adult ? Other than that , brilliant . Exactly the level of technical explanation that we want . Thank you .

[@pegasisilver6249]

How much contact is really needed to be considered a boat?

[@CaptainAhorn]

Where do you put the torpedos?

[@williambrasky3891]

How do they fly them around now?

[@TheEvivzorglub]

Thank you.... Enlightening :)

[@466047]

“Back end of the boat” known to us sailors as the stern.

[@108hindu]

One might say you are a “stern” man.

[@jackmcandle6955]

She has a really nice stern

[@108hindu]

I always check out the stern, first!

[@phillipbotha7920]

Looks like they are trying to use ground effect

[@Power5]

Why have no teams dimpled the above water hull panels?

[@jazldazl9193]

they are not golf balls

[@Power5]

Yeah I am not an aeronautical engineer so I assume a golf ball spinning is why the dimples may help a ball but not a sail boat.

[@steviebee1989]

Are there any Americans on the USA crew or are they all Kiwis?

[@trajan231]

There are several Americans on the American crew

[@katerinakemp5701]

Think could be more kiwis than anything else probably a handful of ozzies as well with a couple of token americans.

[@MP48]

By when must ETNZ launch their second boat? I thought its only before the cup match itself?

[@darthdredd4148]

I'm to believe that Antonov is a Ukrainian Company ,The plane displayed in the video has Ukrainian colours/Flag on it. While this plane was designed and built in the 1980,s during the time of the USSR ,it was designed and built in the Ukraine . So its actually and always has been a Ukrainian plane or Ukraine-SSR . (designed in the 1980s by the Antonov design bureau in the Ukrainian SSR, then part of the Soviet Union.) So barely russian. Yes Ukraine at that time was part of the USSR I put forward that once that union collapsed this plane became completely Ukrainian, its designed there, built there,maintained by Ukrainian engineers. With all that's going on ,I'd have said this Ukrainian built plane during the time of the Soviet union....etc etc. To me that's more accurate than calling it russian . I just don't see how this can still be called a russian plane. Anyway just saying , Slava Ukraine ✌

[@toadster20000]

Is it still sailing if they aren’t in the water ?

[@vsinulingga]

so which one is faster theoreticaly?

[@tomhollins5303]

Without any experience of designing multi million pound racing boats obviously... the size of the skeg at the bows surprises me if its purely to stop slip of air under the boat. As the boat is travelling through the air so fast surely the pressure gradient will building at a diagonal as you go down the boat. So much pressure right at the bow seems unlikely. Also to compare to winglets on airplane wing tips, the width of the hull must close off a lot of the spill. I wonder if there is some additional reason. Is the boat likely to need extra resistance to torque in the horizontal plane when not fully lifted on the foil?

[@phranklyn]

"Patriot"....... *rolls eyes*

[@RubyDoobieScoo]

Cringe worthy

[@JamesSmith-ui2hv]

such a revolutionary name in times when so many idiots do not valued their country .

[@jazldazl9193]

And a treasonous wannabe dictator at the head smh

[@jb76489]

@@jazldazl9193 orange man bad

[@jazldazl9193]

@@benisrood stfu then

[@patriotjon8535]

Is a Hydra-foil actually a BOAT...???

[@colinsteam]

Great presentation but.....I think the so called 'skeg' is required to stop the boat sliding sideways, like the centre board or keel.

[@andrewpegman4284]

I don’t think it touches the water during sailing. It’s to maintain air pressure I saw

[@harryv6147]

Beautiful!

[@forestboy52]

I don’t see the acceleration from non foiling to foiling being a factor in this cup. The boats will enter the start foiling and stay away from any possible dial up, then remain up on the foils for the entire race. It will all be down to maximising foil efficiency. Which if you can get added lift from the hull shape, and ground effect from the skeg (Ineos) then you can reduce the angle of the wings on the foils = less drag = more speed

[@zbeekerm]

Is there a rule against dial ups? Or do you think that skippers will find it too risky? The starts are upwind this cup IIRC. I'm an aerospace engineer w/ a PhD in fluid mechanics & CFD, but I really don't understand what everyone is talking about with the Ineos skeg "increasing lift" or helping with ground effect. Am I missing something? It will provide a buoyant force to help lift the rest of the hull out of the water, and it's flat bottom surface may also provide some lift from planing action. It may also help reduce induced drag (maybe) by acting as a winglet and help increase lift by extending the sail down to the water more. What am I missing with respect to ground effect? Normally, for planes, this is caused by the tip vortices on the wings being virtually mirrored below the plane of the ground. Any vortex off of the skeg when it's air born will be inducing low pressure on its leeward side and contributing to leeway. Being closer to the ground just increases the impact of this leeward side force through the mirrored vortex, as far as I can tell.

[@andrewgrillet5835]

It all depends on the wind! If the wind is gusty, and the boats dip in and out, quick lifts will be critical. And, on past history of foiling - he who gets up fist gets home first!

[@solstar4778]

What !! Your not going to leave us any mystery! Do they wax and polish between runs ? On the lower hull ?old jets use to do that to get higher top speeds (subsonic) !

[@AceAndyman]

whats a skeg?

[@kiereluurs1243]

That story about the skeg seems nonsense to me. The whole hull functions as a seal underneath the sail. Compare it to a VERY LARGE winglet on a wing. That skeg does not add a lot. What it is? Maybe just for directional stability while in the water.