America's Cup: Wind limits decided by Mediation and Match Conditions are published
by Richard Gladwell Sail-World NZ 13 Feb 2020 04:44 UTC
13 February 2020
Emirates Team New Zealand sailing on Course C - the principal course for the 36th America's Cup - Waitemata harbour - January 15, 2020 © Richard Gladwell / Sail-World.com
The contentious Wind Limits for the 2021 America's Cup and its preliminary regattas have apparently been decided by Mediation rather than a full Arbitration Panel.
Emirates Team New Zealand have had to concede a reduction in the wind limit sought from 24kts to 23kts for the Match. That would indicate that they struck a mid-point between the 22 knots sought by the Challenger of Record and the higher 24kts level proposed by the Defender. The normal racing limit is 25kts in Auckland, or more if safety is not compromised.
The Challengers have opted for even lower upper wind limits of 21kts for the Round Robins and Repechages, and 23kts in the Challenger Final for the Prada Cup. For the Race Conditions and Race Schedule for the Challengers Race Conditions and Race Schedule for the Challengers
A curious twist in the Wind Limit conditions requires the true wind speed limits to be corrected based on "forecasted tidal currents in the area where the race committee signal boat is located".
That system was last used in San Francisco and resulted in the wind limit being adjusted from a low of 19.9kts one week to 24.5kts in the final week of racing (by which time Oracle Team USA had mastered the art of foiling upwind), and successfully defended the America's Cup.
The tidal adjustment to be used in Auckland has minimal effect on boat design, however it does have a significant effect on whether racing can get under way at all, and more importantly whether TV schedules can be met if the wind slightly exceeds the arbitrary limit. Certainly when wind limits have been rigidly applied in the area in the past for live TV coverage of match racing, there have been serious scheduling holes, when in the absence of a wind limit racing would have commenced on time.
In San Francisco, because of the geography, the tidal flow was directly with or against the wind direction on the America's Cup course. However for Auckland with several channels and an estuary flowing in an out of the Waitemata harbour, the situation is a lot more complex. Additionally, the tidal flow is less significant than San Francisco. In Auckland the tide swirls rather than being in a constant direction. The variance in strength and direction raises the issue of why race organisers are even bothering with the potential TV stopping tidal flow complication - given that the AC75's are sailing in an apparent wind of up to 60kts, and a knot or so of tidal effect on the race boats is going to be negligible. Using the Race Committee boat as a measurement point for strength and direction, is just an academic exercise, and a different tidal angle and strength of flow will exist further up the course.
The lower limit for racing is also affected by the tidal flow factor with a lower adjusted true wind speed of 6.5 kts. Additionally racing is controlled by time limits of 12 minutes for the first leg (based on a VMG of 6kts for the 1.2nm leg) and a limit of 45 minutes for the whole race.
The wind measurement system used is similar to Bermuda in that wind strength is measured between nine minutes and four minutes on the countdown, on a rolling 30 second average. If the upper or lower tide adjusted wind limit is not exceeded then the start proceeds and the race continues, regardless of whether the wind increases beyond the limit.
Repechage back in Race Schedule
The Race Schedule for the Prada Cup calls for a Qualification Round of four Round Robins, followed by a seven-race Repechage series. Given that it is unclear as to whether there will be three or four Challengers, there is no progression stated through to the Challenger Final for the Prada Cup.
However assuming that there are three Challengers fronting in Auckland, racing will start in the first Round Robin in January 15, 2021 and will continue from the Friday to the Sunday January 17, 2021 - with two Reserve Days allowed on January 18 and 19, and two No Race Days on January 20 and 21, 2021.
With three Challengers, one will race twice on a Race Day, and the other two will race once. Boats are expected to score a single point for a win, and the boat with the most points wins the Qualification Round.
The same pattern will be continued until the conclusion of the Round Robin phase on January 24 (or January 26 including two Reserve Days.)
With four Challengers there will be a requirement to use a Reserve Day each Round (of which there is currently two per Round plus two No Race Days). Every boat sails two races per day. There are no races from which one of the boats is excused, and the race program is more intense - which is good for the competition and good for the spectators.
It would seem that the winner of the Round Robin phase will go straight through to the Final of the Prada Cup which begins on Saturday February 13, 2021
The other two Challengers will sail a best of seven Repechage Series, with the winner also going through to the Final of the Prada Cup.
If there are four Challengers then the schedule will be adjusted slightly, but the main change will be that three boats contest the Repechage phase, with two to be eliminated.
The advantage of the Qualification and Repechage format is that all Challengers are kept racing longer and stay in the event until early February.
In the Final of the Prada Cup, beginning on February 13, there will be two races a day between February 13-22, with Reserve days on February 15,16 and February 18, and also February 23 and February 24 if required. There are no No Race days scheduled.
Configuration declarations required before series
The America's Cup Match gets under way on Saturday March 6, 2021 with two races per day starting at 1600hrs to allow the breeze to settle in strength and direction. The late afternoon start is because the Auckland isthmus is prone to sea breezes from its east and west coasts - with the Tasman Sea to the west and the Pacific Ocean to the east.
While there are no No Race days in the America's Cup Match, there are several Reserve days that can be used at the Regatta Director's discretion. The Match will continue to be sailed every day after March 15, if required to achieve a result.
In all series the competitors will be required to declare a boat configuration before the start of a Round or other phase of the regatta, and 120 hours before the start of the America's Cup Match.
The boat configuration must include the hull being used, the foils (incl. fairings, wings and flaps), the upper and lower rudder and the mast tube.
The reason for the configuration declaration is to prevent teams moding their boat each the day, as happened in Bermuda, depending on the weather forecast.
For the Match Conditions of the 36th America's Cup Match
The main effect of the requirement will affect foils where the teams will have to use one set that is capable of being used in all weather (AP or All Purpose foils) rather than a light air set, and then an AP set as the teams used in Bermuda. Requiring an AP set only to be used obviates a lot of measurement process each day for the teams but also measurers having to check certified gear changes before and after racing. Boats will still be subject to regular measurement checks.
Replacements must also be nominated at the time of the Configuration Declaration, a complex process which runs to over two pages of the Match Conditions.
A separate clarification has also been issued on the five-course areas announced previously, stating that the boundaries are indicative only and that racing maybe moved within the areas by the Regatta Director.
The note sets out a priority for the course areas, with the #1 Priority being Course C in the vicinity of North Head at the entrance to the Waitemata Harbour - which will be used in WSW, SW and NE wind directions. #2 Priority is Course A off Milford Takapuna - suitable for all conditions, subject to sea state in onshore winds. #3 Priority is Course B in the Rangitoto Channel.
It is assumed that the Rangitoto Channel and approaches to the Waitemata harbour will be closed to shipping during the racing.
For the official Notice on Course areas and priorities