The American Magic Capsize - A Step by Step Explanation 

We really need more of this - I'm a complete newcomer to sailing, and this level of insight and explanation (especially of basic terms like 'easing the mainsheet' and 'leeward and windward backstay') is so helpful. Thank you!

This analysys is excelent. More of this please. I am loving the comms audio from the boat.

Awesome analysis, yet again the coverage of this America’s cup astounds me. I know it helps having such awesome boats and quick races, but the quality of the output is just brilliant. As a keen sailor I had always found watching it on the screen a poor experience. This changes everything and has made sailing better tv viewing than any stadium sport, and that is a really hard ask for such a technical sport. Keep it up.

Ken Read and Nathan Outterridge amazing job, bravo

thank you for the analysis- hind sight is always 20/20, but at the speeds here, decisions happen at warp speed. best of luck to American Magic.

Seems like the AC boat acted just like a Windsurfer. Without the jib providing pressure forward, to pull the bow down, coupled with the main being held from releasing pressure, the boat just did what all boats do -- they weathercock to weather. Want to bear off? Keep the jib working and let out the main -- get those aero forces forward of the keel/centerboard and in this case, the foils. And it might be that there was a lot of hull speed at that point too, with the high angle of attack and the foils provided some extra lift ; that they were pushing the hull high due to an abnormal foil angle of attack.. And we have to remember that the forward part of the hull is quite rounded to aid in flow to the jib, and once the hull started to go bow high, there might have been some small aerodynamic lift to the bow section (somewhat akin to a cylindrical body giving lift to aircraft) making matters worse. But the weather-cocking is really obvious in this video. , Thanks -- had not seen this before.

At 7:00 Kenny says three times.. the leeward backstay is supposed to be loose, "and it's not." Nathan nods in agreement, then changes the subject. Everybody knows it's supposed to be loose. We want to know why it wasn't eased, who or what controls it.

I've made this mistake a few times, as a kid on a Bluejay in junior sailing and on board an Express 37 in SF bay. Too bad the boat broke. On the Express the mentality was not if you were going to broach, but when, and how fast you could clean up the mess and keep racing. It's obvious that these boats are really hard to sail, I just hope they don't scrap the design and move on before perfecting how to handle them! 44kts on a sailboat! amazing!

Fantastic and dramatic analysis of big speed, big time and big money sailing...AND big gambling tossed in as well...WOW!

I’m new to sailing. Watching not on the water. Brilliant insights and explanation. Can we have a few programs for beginners. I.e. 10 mins on what all the terminology means. Thanks for the upload.

This is an excellent walk through of what happened. The explanation of the shipboard communication is spot on. The nautical terminology, how it relates to what is occurring reinforces its necessity. Many people often question me about the exacting terminology used by sailors. I always tell them that it comes down to your life depending on it. It is one thing to say that the port jib sheet jammed in the block while on the other to say the left sail rope is stuck. Also, consider that the person that is facing you that is being told that is looking aft! The first thing I learned about sailing from my skipper, Goldeneye Gordy - may he rest in peace, is spill the main. SPILL THE MAIN! Of course, you can't do that if you only have six inches of travel and a batten hanging up on a backstay. Events overtake you, especially in races where you are pushing the limits. My question is, how did the hang on the backstay happen? This is NOT the way a mainsail works. There was a failure in insuring that that did not happen. Someone missed that. Thanks for the breakout on this. My curiosity still remains unsated, though. I also want to know about the dynamics and the design parameters that lead to a huge gaping hole in the hull. What actually caused a square hole in a "round boat"? Sorry, couldn't help myself there. There is more to this story. I hope you can enlighten us.

Great detailed analysis on all points: 1) helmsman made a poor decision to take a course that was far more risky under the higher wind circumstance - a blunder made even more apparent with the boat's 480 meter lead going into the gate 2) while the traveler was maxed out, the mainsheet was not eased appropriately given the wind conditions and bear away tack maneuver that was decided upon 3) port or leeward backstay was not eased sufficiently or at all which inhibited the main sails ability to dump pressure/stress on the boat 4) helmsman cranked rudder hard to 90 degrees as it was lifting out of the water causing it to act as a strong brake upon reentry - likely intensifying the impact of the forward area of the boat as it slammed back down in the water Four significant and largely inexcusable (in the arena of the highest levels of competition) human errors resulted in a serious accident that caused heavy damage to the boat and thankfully did not result in serious injury to anyone onboard.

I think poor Dean is getting too much flack. In strong winds cruising boats often tack instead of gybe to change gybe as it's much safer and controlled. Dean executed the tack fine and bore off rapidly to prevent a broach as normally a yacht has less pressure on the rudder downwind than reaching. Unfortunately Patriot didn't have the ability to do a 'big ease' of the main (and probably the jib) as the traveller, mainsheeet and runner only have a little bit of travel as the apparent wind is normally forward of the beam. In the end it's all about flight control as the power in the rig is vastly more than the power of the foils and trim tabs. Tack or gybe poor Dean was in charge of a bucking bronco when the gust hit and he didn't have enough control. I suspect something heavy came loose inside the boat (foil actuator battery?) and punched it's way through the thin carbon skin when Patriot slammed down, which turned a regular capsize into a disaster. Anyway, good luck to Patriot 2.0 (until you meet Ben!)

Still no talk about *why* the leeward backstay didn't get released. That's the one thing I was expecting to learn here.

You two are bloody great. Thanks for taking commentary instead of being on board!

Great summary. I really don't understand why AM didn't take the easier mark rounding. They were so far ahead of LRPP and there was clearly a high risk to the manoeuvre they performed. Sadly we will never know if they could have taken on the kiwis, and won

I've always admired Nathan's sailing; he does it all and he's supremely talented. But his development as color commentator has come so far. This vid is evidence of that. Hope to see him racing GP in 2021.

This analysis was as thrilling to watch as the racing itself. 👍 Thank you for explaining what really lead up to the wreck. Seems like the old scenarios in aviation cockpits when a first officer couldn’t correct the Captain before disaster happened.

Great analysis guys. However why no mention of Mr Hutchinson? It it normal for him to have no opinion on which mark to take? Also, are we sure that Dean’s backward look was not to check on the threat from Prada?

Thanks for the play by play! Really loved seeing the intricacies of the sport....Hope American magic has better luck after fixing their boat!

Great explanation guys. Very interesting to see how complex the decision making process is and how making these split-second calls is crucial to the performance of the boat. Exceptional team work!

Thank you for making the America's Cup so accessible, wonderful analysis.

Well done. I'm a new fan so I'm at the bottom when it comes to knowledge and such. Thanks for explaining things so well.

Best and clearest analysis I’ve seen so far. Thanks for your work on this - great job 👍🏻

Wonderful. This have initiated a major discussion with my 5 junior family sailors. Many lessons to be learned from this for all sailors and non - sailors. Thank you

I think one thing the guys didn't mention is the speed of the boat on bear away... On these kind of boats it's much easier to control bear away at full speed, if you are going slower your apparent wind moves back and easing sails has less of an effect when it comes to depowering, if they made the right turn then they would have initiated bear away with boat speed over 40 knts, I'd be surprised if they were doing over 25 on exit of the tack, and then straight into bear away... Hindsight is a wonderful thing hey!!

Fantastic analysis. Thank You. Would you guys watching on, have taken the bear away gybe around the right gate mark? All due respect to Dean Barker, I know he may have been pushing the boat to see what it could do, at 40 knots, the tack bear away was a gamble. Pity the Main hooked on the Leeward backstay. I

The traveler max position has been shown and discussed by previous media and this video reinforces that fact however there is no reference to exactly how much sheet release there was available and if it was released would that have prevented a capsize with the dramatic wind speed shift. Also, during the press conference it was stated the team did not want lighter air to the right and opted heavy air left so was this a sheet setup mistake or just a bad luck wind speed gust?

Helicopter wash - had to play a role it was just above the boat. It passes over at 7:30 on the time line but had been there awhile and much lower at 0:51 - just over the water.

Great piece thanks for stepping though it, but I cannot bring myself to like it, how gutting it was for the team. But how exciting and on the edge the AC75s are

They said the back stay was suppose to be loose and it wasn't. Why is that? human error, just back luck, equipment failure?

Happy when you use your marker to teach me the details. Most enjoyable!

Any idea why the backstay wasn't slackened? What controls it?

Great explanation. Now can someone please explain the explanation?

Thanks for the analysis, very informative!

What is missing is comment about what punched the hole in the bottom of the hull. It clearly had to be something big and heavy inside getting loose and breaking through. I'm guessing it could have been batteries for the onboard computers and controls. Nothing else I can think of could do that much damage so quickly. So, who designed the battery system and the installation. I had to be under designed I'm thinking. Any insights?

Why isn't anyone commenting on the steering, @5:35 you can see the helm steer to starboard (also this is when spray start to fly off the windward side of the rudder), this seems to push the stern down, increasing the AoA on the foil. I would think you should hold the helm down in a bear away, using centrifugal force to help keep the boat level?

So if the Bare away Jibe to the right was a smarter tactic during the puff and was 100 meters closer then why did Barker not listen to Goodison? Maybe Goodison should get a chance to lead this AMERICAN MAGIC team around the course. He seems to make good decisions under pressure.

I've been wondering if, at the point where the boat is well over and potentially going to capsize, there would be enough time to lower the windward foil to increase the righting moment. Tough for the crew to do in this situation but an automatic lower in the event of extreme heel might make a difference in marginal conditions.

Is Dean Barker the greatest choke artist in the modern history of the Americas Cup?

This is what happens when you don't want to just win by running your own race, but try to control the other teams race as well. Could have taken the "easy" path around to the right, but he wanted to stay in phase with Luna so went the hard way. He didn't want to just win, he wanted to make it look like they dominated the other team.

Excellent analysis guys. Best commentary on the cup out there. Keep up the great work.

Fantastic video and commentary! Wonderful (and sad) to see and hear the moment to moment decisions, action and consequences. Great work Ken, Nathan and the video crew. American Magic...not so much.

There was an analysis by a pilot (Juan Brown) who described this in terms of wings stalling. Conclusions all the same, of course. Fascinating.

Diamond shaped drive sails. I haven't thought of a better way to mount it than with slap wristband technology.

Okay. I'm coming to the party late. Here is what I see. By tacking while going 40kts, they radically increase the apparent wind over the sails. Then, they ventilate the rudder foil and the entire rudder mast (maybe a ventilate/cavitate combo). Thus, the boat gives up control over the angle of attack of the lifting foil/wing, and it launches for the surface, as the boat rounds up into the wind, then the lifting foil/wing breaches the surface and all foils are now ventilated and ineffective. Conclusion: by jibing, they would have reduced apparent wind speed over the sails, and would be more likely to prevent ventilation/cavitation of the foils - which may have exceeded their pre-cavitation velocity for a moment (a split-second is all it takes).

At last the explanation, brilliant. What I would like to see is the actual recovery, when they righted the boat.. Please

A common refrain in these post mortems from commenters (likely personal acquaintances or supporters of the individuals involved) has been that this is just a racing accident and that unexpected high winds were the root cause. I would remind those reading that these sailing teams have been testing foil sailboat limits for years now and SHOULD have been keenly aware of the boat's limits with regard to high wind exposure at all points of sail and foil configurations . From the audio, it was clear that the tactician was aware of the limits and voiced his concern. The helmsman visibly acknowledged the tactician's advice yet clearly ignored/over rode that advice as they approached the gate - with the end result being loss of control, crash, and near sinking.

I really don’t believe a jibe in this monster would have been safer unless they were miles away from that squall line. Running backs suck, have always been a pita, and source of much angst. I’m stunned at what people are implying about them shortening the slack to save weight. Great idea until a situation like this. But I’m going to assume they could have eased everything a lot more, but choked, and I feel bad, and just glad it wasn’t me. In one slow motion shot of the wheelie I could have sworn I saw the whole hull twist a bit but maybe just my imagination. Wonder if there was a lot more structural damage than we’ve been told about.

I used to tip my Sunfish in the Thames River, always got it back up myself. Just stand on the rudder.

Top tier forensics...well done!

Maybe it's not the failure of the sail hanging on the backstay but the design of the sail that caused it to hang up in the first place. Or the placement of the the stay wire to interfere with the sail? I know that the cut of the sail will determine the power it might deliver. Why is the sail, backstay so placed to interfere with each other? (sort of like an interference engine, everything is fine, until its not and the piston hits the valves, causing way more damage)

Excellent analysis - more please!

is one of the problems that Dean slowed down while going thru the wind that caused the apparent wind to go aft and load up as they turned down wind?

Wrong hashtag but great analysis

They were freakin haul a$$! Do you think they pulled the right foil up too soon? It looked stable until they raised it. Looks like it was providing much needed leverage against that wind pressure. Maybe they needed to delay that a second or two longer?

all cameras sights from the onboard devices are cut out, while the take off and the capsize.

Excelent analysis! Thanks.

Excellent analysis!

The green light onboard AM is on within 3 boats lengths during the rounding of the mark. At 6:40" the light is off. Could it be that some electrical component has come loose down below which created the "guillotine effect", as explained by Terry Hutchinson, on the hull as it hits the water during the capsize?!

I don't know a lot about sailing but I do have a couple of questions. - When Goodison said to go towards the right mark, it seemed a little too late to make that change. They were only a few seconds away from the mark. How much preparation does the crew usually need to perform a maneuver like that? - Why is a tack-bear away more difficult than the bear away- gybe in this situation? - And the obvious question, why was the leeward back stay still taught?

Great explanation guys

Really well explained

Excellent, thank you.

I hope Dean Barker never ever gets to helm another America's Cup yacht ...What a flamin disaster.

Great analysis.

Do you think if the starboard keel was left down a little longer this would have saved them? Also, what is that whining sound?

Cross support. Hugo boss didnt have exes as supports. Off topic but imocas spend most of the time heeled and apivia had 200 additional kilos of structural support. I've never been on a sailboat I'm observing the architecture. This still wild to me but you guys are wearing helmets and other safety gear. Planing hulls dont plane anymore I guess because there on foils in imocas. I dont know the dimensions but rods formed in an x I feel like hugo boss would still be running vg

Great breakdown

Still don't get why the boat suddenly takes off like that. Up to that point it is under control. Could it be that the foil was generating too much lift? I guess as the boat heels over, the foil becomes horizontal and the lift increases, at the same time not providing lateral resistance any more. So the bow swings downwind and is forced upwards, resulting in take off. The rest is inevitable.

You can’t have too much ken.

I think you can see the damaged panel drift away from the boat at 1:18.

Please lads CAN you do a post on apparent wind and true wind speed how it works //// why did usa not flip the boat on to port after the capsize the hole would have been out of the water earlier on. needs looking at

I’ watch on TV the America Magic is a very WIDE boat unlike Luna Rossa simple and streamline and may be WHY it TIPS OVER EASILY

I alarmed to see that there is essentially no gap between the boom and the deck so the crew on the side that goes under have to swim under the sail to escape. This seems exceedingly dangerous.

Mistakes were made here but that was a vicious localized puff of wind right on the mark rounding. Almost a worst case scenario for these boats. The Italians almost lost it too and they didn't get the full force of that puff like the Americans did.

30 percent less mast delivered to the drive sails using already existing mounting, diamond shape drive sails they have to be neatly retractable and deployable from the unit already. Getting it to roll properly is the challenge in theory. Exo frame drive sails cant be stored and swapped out. Except for a super rc boat with exo frame sails.

Thanks Ken, Nathan. However, I still think there was a causal problem with flight control. Watching the event unfold frame by frame on the YT videos, boat pitch was not corrected as they rounded the mark, went from -1.5° (bow down) to +1°. Nevertheless the boat was still relatively stable, and continued that way into the beginning of the bearaway for another full second. But then the pitch started to increase further, whilst the rudder still had control, until it reached the point of no return. I posted imgs and timeline showing this at SailingAnarchy, the side view at: forums.sailinganarchy.com/index.php?/topic/193692-team-nyyc/&do=findComment&comment=7379031 and the overhead view showing how/when pitch changed at: forums.sailinganarchy.com/index.php?/topic/219703-prada-cup/&do=findComment&comment=7381380

I have the exact same lamp as you guys.

I don't think she would have gone over if someone released the main sheet !

Question for Terry, will the NYYC throw you under the bus for this stunning defeat?

Errori grossolani nei sottotitoli. Per cominciare si parla di "tack", virata, non di "attack"... etc etc

How is the reconstruction of American Magic going?

The helmsman turned the boat too quickly and started turning before he had finished the count down.

Nice - bravo american magic

Helicopter(s) distance(s)?

I believe rotor wash from the helicopter/drone hovering near the marker caused this, it is easy to see! The question who is responsible for allowing a helicopter that low and near to the course? At an airport they would never allow a helicopter to hover near parked aircraft because they make them "fly" then flip over.

*Effing DEAN!!!! Overrode everyone below him it's on his shoulders!*

And, so that amazingly clean hole in the hull was created by... ? The slap on the water or some 'thing' in the boat smashing it's way out when she got slapped?

All because they didn't have the leeward back stay loosened! Unbelievable,!😯

As a saling instructor i know! yet was asked " How can these boats go so fast without an engine ' Clearly so many people have not the slightest clue how sailing works. Please present a simple presentation for the keen new comers, as using sailing terminology is lost to them.

Counting 1 to 3 while in the death zone probably didn't help much either

So are you saying Goodison got scared fear took over & he completely dropped Barker in it, not easing the main & perhaps running backstay if thats his job? Goodluck to the other teams if they think taking the soft option will get them NZs Cup, Dean knows this so if you can't nail your job you better fire him now because I doubt he is going to back off.

40+ knots on a sail boat...

Pilot error, there seems to be a power struggle over the right thing to do and who is in charge.

i tell what annoys me always this america's cup people commentators don't know what they are talking about

kkkkkkkkkkkkkk

it;s about time someone realised that it,s the battery which you can see trying to come out of the hull just before the crash landing at which point it,s punched a hole through the hull and could also be why the back stay did not release.

FOUR skippers ??? ( BIG egos!) Recipe for disaster ... and guess what?...DISASTER !

Fine except the transcription of the talking, which is clearly made by someone clueless...