Cup Spy - Day 10: A Tale of two Semis
by Richard Gladwell Sail-World NZ 14 Sep 14:33 BST
14 September 2024
INEOS Britannia and Alinghi Red Bull Racing - Day 1 - Semi-Finals - Louis Vuitton Cup - Day 10 - September 14, 2024 - Barcelona © Ian Roman / America's Cup
Commentary: A Tale of two Semis
At the end of four races sailed in a funky southerly 8-11kt breeze and apparently flat sea state, what was really gained?
Comparing the margins between the two pairs of AC75s in the Round Robins, with the margins in the Semi-Finals, INEOS Britannia today beat Alinghi Red Bull Racing by greater margins than they were able to achieve in the Round Robin racing.
In the other pairing Luna Rossa beat American Magic by smaller margins than they achieved in the Round Robins.
There was one lead change in the two matches between the Swiss and British teams. Only once in 12 mark roundings did the Swiss lead.
In the other Semi-Final pairing USA led around four marks in the first match, and around two in the second. Bottom line is that the mark rounding "wins" were evenly split with six wins each. However all the Italian wins came at the end of the racing - which are the ones that count on the leaderboard.
From that there are two quite different processes running in each of the Semi-Finals.
The British are not seriously being pushed by the Swiss - which is the usual outcome when the top finisher is opposed by the bottom finisher from the Round Robins. Yes, the Brits sounded very good and confident in their communication and had quite easy wins.
An analysis of the JSONL performance files - shows there is not a lot of difference in speeds between Luna Rossa and American Magic. But there is significant differences in the ride height with American Magic and flying lower and probably landing more than the Italian.
The problem INEOS Britannia faces is not winning races, but how to up the tempo of the racing so they are testing themselves under competitive pressure and learning - and they don't go into the Challenger Finals underdone.
The Brits have to get out of their comfort zone.
Luna Rossa are getting a much better workout, having to come from behind in both races, and also having to maintain contact while being hosed down with rig turbulence by American Magic, especially in their first race.
The Italians once again got their jib calls right thanks to some astute calls by coach/meteorologist Hamish Willcox, and even more significantly the Luna Rossa team were prepared, as they have done before, to let him make the call to change jibs between races. They're race winning calls.
From what we saw today, Luna Rossa are going to come out of the Semi-Finals in a lot better shape than than INEOS Britannia. While American Magic are definitely on the backfoot, at this stage. Their big credit, from both races, is rounding the top mark first in both. Statistically 80% of the races are won by the boat which is first around the first mark.
Of late, Luna Rossa seem have a problem in starting and first tacks - but in most of the Round Robin racing the Italians led around Mark 1.
The communications on board Luna Rossa, like the Brits, sound good. The difference between the two teams is that one is having to think accurately under racing pressure and the other isn't.
American Magic still have a problem with staying foilborne. Arguably they lost the first race with a wobbly rounding at Mark 4, although they still had a lead of a couple of hundred metres. However that can go in a flash - and the slip-up certainly opened the door for the Italians.
On post race analysis the USA only dropped a couple of knots in the "speed wobble" which occurred as ITA rounded Mark 3. The Americans increased their margin out to over 200 metres as they sped towards the starboard layline. Where the damage was done occurred further down the leg when Luna Rossa got what their co-helmsman liked to call a "Kiwi puff" in Auckland. Virtual Eye shows American Magic and Luna Rossa sailing at the same speed over the ground (37kts), however the Italians have picked up a 15° shift which is just 1kt stronger, but by being able to ride it, the Italians VMG is 5kts faster. Surprisingly that variance occurs when the two AC75s are on just 155metres of separation.
That analysis exercise calls into question the lack of wind information being displayed to fans. With the wind direction and speed displayed on Virtual Eye, at the point where Luna Rossa is reeling in American Magic, there are nine wind measurement points down the port and starboard course boundaries, there is a variation of over 15° in direction and 5kts in strength across the nine points.
The Italians gybe and ride the same puff which doesn't reach USA, the race leader until a minute later. But the damage is only partially done, and Luna Rossa continues to gain. Just 120secs after beginning their Barcelona sleighride, Luna Rossa has chopped a 200 metre lead down to just 4 metres, and trail American Magic by just 4secs at Gate 4 - after the US AC75 picks up 1kt stronger breeze from the same direction and extends the margin out to 34 metres as they line up to round the same gate mark.
It was a superb piece of sailing and team work by the Luna Rossa crew. The wind information shows there were plenty of opportunities on the Barcelona course for those who could position themselves to take advantage of them.
[Virtual Eye is an excellent analysis tool as there is more information displayed than on the video , and you can control the view you want. You can try an run Virtual Eye yourself - instructions are at the bottom of this story. Choose SF2 - Race 1 and then progress to Leg 4]
Today there was a camera on the recumbent cyclors on American Magic - Crotch-cam.
Without the ability to use their bodyweight on the pedals, it is hard to believe they are getting the same power, or anywhere near it as the upright cyclors on the other teams. Outwardly the US boat seems to run out of juice more quickly than the others, and the cyclors seem to be on a hiding to nowhere.
Alinghi Red Bull Racing also seems to have issues staying foil-borne and really got stuck in the second pre-start. For what seemed to be a long time, they were near stopped, while the British were flying around at 38kts.
However full marks to the Swiss for being able to get their AC75 back on the foils before the start, when they were under huge pressure. Unfortunately they picked up a 150 metre penalty as a consequence of their foiling recovery, and were never in the hunt.
There has to be some serious improvement take place if the Swiss are to stay in the regatta beyond Monday.
Saturday's Live race coverage:
Race Summaries:
Semi Final B: Match 1: ITA vs USA Start: 14:10. Entry: Port: ITA Stbd: USA
The start was delayed after American Magic called for a 15 minute delay to rectify an onboard issue - apparently for a communications system issue. Both entered the start box correctly. Breeze around 10kts and flat water. USA led ITA going to the line, and ITA was forced to tack just before the start and head for the beach (starboard boundary). USA tacked to cover. ITA came off the beach first and after some back and forth USA got in a covering tack and feed the Italians gas all the way up the beat in a 9.9kts of breeze.
Mark 1: 4m 28sec USA leads ITA margin 3secs
Mark 2: 7m 46sec USA leads ITA margin 20secs on the water the margin on Leg 3 is out to 240metres
Mark 3: 11m 57sec USA leads ITA margin 16 secs.
Mark 4: 15m 10secs USA leads ITA margin 4 secs. USA did a wobbly rounding at the top mark allowing ITA to close up, but still had a 200metre lead on the water. ITA closed up quickly as they went down the later stages of Leg 4, and passed.
Mark 5: 19m 9secs ITA leads USA margin 22secs
Finish: 22m 12secs ITA leads USA margin 7secs or 116 metres on water
Semi Final A: Match 1: SUI vs GBR Start: 1500hrs. Entry: Port: SUI | Stbd: GBR
Both were late for the start. SUI to windward of GBR. SUI led off the start by 50mtrs, and covered GBR as they sailed tack for tack up the starboard boundary. SUI stretched lead to 100metres hanging on longer to save tack to round first mark.
Mark 1: 4m 37secs SUI leads GBR margin 11 secs. On Leg 2 both go for the starboard boundary. GBR applies pressure and sailing faster passes SUI.
Mark 2: 8m 16secs GBR leads SUI margin 28secs or 270 metres on the water. On Leg 3 Brits maintain a loose cover and stretch margin to 380metres.
Mark 3: 12m 31secs GBR leads SUI by 42secs. Stretch lead to over 1000metres on Leg 4 downwind.
Mark 4: 16m 01secs GBR leads SUI by 84secs
Mark 5: 20m 31secs GBR leads SUI by 80secs and 1470 metres on the water.
Finish: 23m 32secs GBR leads SUI by 125secs.
Semi Final B: Match 2: USA vs ITA Start: 1536hrs. Entry: Port: USA | Stbd: ITA
Both made their final approach to the start line on starboard, with ITA to windward of USA. ITA was too early and had to rundown the line towards USA which was aimed at the pin at the leeward end. ITA had J2 jib - call by coach Hamish Willcox. ITA was first to tack off at the start
Mark 1: 04m 19secs USA leads ITA by 10secs
Mark 2: 08m 06secs USA leads ITA by 06secs after USA came off foils because of bad line into mark and unable to keep foiling.
Mark 3: 13m 23secs ITA leads USA by 20secs. Lead extends to over 300metres on Leg 4.
Mark 4: 16m 45secs ITA leads USA by 14ecs margin down to 220metres. Wind 9.6kts - 9.9kts. Increases to 11.6kts on downwind leg on starboard boundary.
Mark 5: 21m 10secs ITA leads USA by 13secs. Margin 120 metres. Wind 9.6kts
Finish: 24m 26secs ITA leads USA by 18secs.
Semi Final A: Match 2: GBR vs SUI Start: 1617hrs CET. Entry: Port: GBR | Stbd: SUI
SUI came off foils 2m 30secs before start. GBR sailing at 36-38kts. SUI gets back on foils 60sec before start. GBR leads off start by 125metres. SUI carrying penalty at start and not cleared until 180metres astern of GBR>
Mark 1: 3m 51sec GBR leads SUI by 78secs.
Mark 2: 7m 12secs GBR leads SUI by 82secs. Wind 10.8kts on Leg 3 on water margin 860metres to GBR.
Mark 3: 11m 08secs GBR leads SUI by 80secs.
Mark 4: 13m 51secs GBR leads SUI by 94secs
Mark 5: 17m 25secs GBR leads SUI by 99secs or 1450 metres on the water.
Finish: 20m 33secs GBR leads SUI by 97secs or 1377 metres
Pre-race commentary:
Racing got away at 1420hrs CET | 1220hrs UTC on Day 1 of the Semi-Finals of the Louis Vuitton Cup - in a breeze that blew up to 12kts, but mostly lighter. There was a mild seastate which appeared to have little effect on racing. Winds were expected to increase during the afternoon, making the correct jib choice difficult.
Accurate helmsmanship, along with precise flight control will be at a premium today to avoid foil washout at critical moments.
The Semi-Finals will see Round Robin series winner INEOS Britannia pitched against the Swiss team Alinghi Red Bull Racing, who was the fourth qualifier. The other Semi-Final is between second placed qualifier Luna Rossa Prada Pirelli and American Magic who finished third in the Qualifiers, which finished on Monday.
The winners of their Semi-Finals will be the first boat to win five races in the best of nine series.
Two races are planned for each pair, each day - making four races per day. The same wind limits will apply as for the earlier rounds of the Louis Vuitton Cup - a lower limit of 6.5kts and an upper limit of 21kts, measured at the top and bottom of the course (start line) using recording devices on each gate. There are a total of four devices, with the readings averaged over 30 second intervals over a five minute period between the 9th down to the 4th minute before the start. If the wind is within the allowed limits the Course Director will make a radio call (heard on the TV commentary) telling the crews that the racing is going to proceed.
If the go-ahead is given then the race proceeds regardless of what the breeze does regardless of the wind limits. Once the go-ahead is given, the only constraint on the race is that teams must make a first leg time limit of 12 minutes, and then a race time limit of 45 minutes. The length of legs, compass direction of the next leg and number of legs can all be altered by the race committee during the race.
To date no race has gone over 25 minutes duration.
The race director has the power to not start racing (even if the breeze is within the prescribed limits) if he considers the sea state is unsafe. He also has the ability to call off a race for safety reasons - a power which he came close to using during the lightning strikes on Day 5 of the Louis Vuitton Cup. However Emirates Team NZ's decision to drop out of their race and sail beyond the 100metre boundary line, triggering their disqualification, and the immediate awarding of the race to Luna Rossa, meant that the Chief Umpire's actions forestalled any action on safety grounds by the Race Director.
Our coverage includes Weather, Live video, Updated images live from the race course, mark rounding statistics, rounding times, margins, and other commentary.
Course Location:
Weather Information - Louis Vuitton Cup - Semi Finals - Day 1
Weather Prognosis:
America's Cup Weather Partner PredictWind has provided a dedicated Race Weather Center offering fans access to detailed daily weather breakdowns, live webcams and historical weather data to daily weather breakdowns written by meteorologists.
Provisional Forecast Race Day 10:
Saturday Sept 14th
In the morning, there will be a weak offshore wind. In the afternoon, we expect a South-South-West wind from 200° to build progressively in strength. By early afternoon the wind speed around 6 knots will increase up to 12 knots by late afternoon.
Waves of 0.6 meter from the East direction at 5-second interval are linked to the strong Northly winds way offshore. Those waves will be roughly 90° to the wind direction.
It will be a perfect sunny day with air temperature up to 25°C on land and 22° on the water.
Sunday Sept 15th
Sunday will see a repeat of the previous day. The Southerly breeze will come in the afternoon with similar strength. Sunny sky and temperatures 1 or 2° higher should make a great racing day.
Arnaud Monges, former America’s Cup Team Meteorologist
Sailing Program - Day 10 - Louis Vuitton Cup Semi Finals Day 1
Semi Final B: Match 1: ITA vs USA Start: 14:10. Entry: Port: ITA Stbd: USA
Semi Final A: Match 1: SUI vs GBR Start: time to be announced. Entry: Port: SUI | Stbd: GBR
Semi Final B: Match 2: USA vs ITA Start: time to be announced. Entry: Port: USA | Stbd: ITA
Semi Final A: Match 2: GBR vs SUI Start: time to be announced. Entry: Port: GBR | Stbd: SUI
Crew Lists
Pairings and Matches - Louis Vuitton Cup Semi Finals
Virtual Eye
Now, or after the racing you can replay the key points, or the whole race using Virtual Eye from ARL
You can go directly to the Virtual Eye America's Cup coverage by clicking here and click on "Watch Previous" then select the race you wish to view. This s 3D viewer so you can zoom in, out, around and up and down just like you could in a helicopter.
Additional Images: