So far, the Vendée Globe in the South Atlantic has been extremely interesting. No trace of the usual "column sailing" of earlier versions of the solo non-stop race! This time the top group is closer together than ever, and they have already had to deal with several tricky weather systems.
There were also big differences in their strategies - and different routes depending on their position. Thomas Ruyant on LinkedOut and Charlie Dalin on Apivia, for example, decided to sail a western route in order to be the first to benefit from a low. However, since the weekend it has become clear that the top 10 boats are now beginning to compress again. This race is far from over.
The first boats should reach stable east trade wind conditions north of the 18th parallel around Wednesday noon. Until then, there are some challenging obstacles for the leaders to overcome and those who sail behind them have opportunities to make good miles.
Let's take a closer look at that.
Figure 1: The St. Helena high is forming anew. A low wanders in the same direction and pushes the old high towards South Africa. The normally strong trade winds further north are quite weak at this point
The St. Helena high, which dominates the wind conditions in the South Atlantic, is currently shifting. A low "pushes" it out of its position towards South Africa to the east. The low moves with it and leaves a windless zone on the coast of South America. Here the St. Helena high will be renewed and the process will begin again. Depending on how the gravure systems affect the high, this will affect the speed at which this process takes place. It can also have a major impact on the strength of the trade winds that are propelled from the St. Helena High. The high is currently west of the leading group and is slowly working its way east. The Vendée skippers make the most of the south and east winds around them. All of them except the leader, Yannick Bestaven, who is now far north of the high and approaching a fairly impassable zone with low gradient winds
Figure 2: By Tuesday, the new high will begin to shift to the east and will also change its shape due to the low developing behind it. For a better understanding, we superimpose the movement of the air masses here: red arrows indicate warmer air, blue arrows cold currents. There is also a clear wind line north of the low. The colder air drifts north, east of the high, and meets the warmer air in the large, low pressure differential area
The quickest way to the north is through the high to the northeast, where the wind turns with it. Then you have to jibe at the right moment and try to get as far north of the high pressure as possible, where the wind blows further ahead. The course resembles the shape of a seagull's wing, a classic pattern. From runner-up Charlie Dalin to Maxime Sorel in 10th place, everyone is following this tactic.
Figure 3: Air temperature at the surface level illustrates the movement of various air masses well
There are small profits to be made in this phase, on the one hand through the perfect timing of the jibe, on the other hand through good boat speed. Boris Herrmann on "Seaexplorer - Yacht Club de Monaco" seems to have shifted up a gear on Sunday. He enjoyed the shallow water conditions which allowed him to use his long foils and sail faster than the boats without hydrofoils around him. As a result, he improved from 11th to 7th place at the weekend.
But north of the high, miles can be gained as well as lost. The St. Helena high often drives the trade winds here, but this is no longer the case due to its current position. A big hole has opened up here, and it's almost like there's a barrier where the wind turns off. A boundary between two air masses of different temperatures is causing this, and it will prove quite difficult to get past the fact that the trade winds don't start to reestablish themselves until Wednesday morning.
Figure 4: On Monday lunchtime, "Maître Coq" and "Apivia" fight their way north through lighter winds. In this way, the boats behind, such as Boris Herrmann's "Seaexplorer", can significantly reduce their deficit and sail in more favorable easterly winds that are generated around the high pressure
It looks like Yannick Bestaven will reach this hole first, after which his pursuers, sailing with better winds, will line up behind him. There are currently 600 nautical miles between the leader and Maxime Sorel in 10th place, which is very little in the Vendée-Globe relation at this advanced point in the race. On Monday and Tuesday the gaps can shrink even further, to 50 nautical miles between Bestaven and Charlie Dalin and 150 nautical miles to the rest of the top 10. Almost a kind of restart. Towards Tuesday evening the St. Helena high will be east of the fleet and in this position will intensify the trade winds - first along the Brazilian coast and then further out on the South Atlantic. On Wednesday morning it should be clear who made the smoothest transition to the eastern trade winds. The ranking list could look very different then than it is now
Figure 5: By Wednesday the front runners will have reached stable easterly trade winds and are making rapid progress towards the equator
Initially, there is still a pronounced north component in the South Atlantic trade winds. This means sharpened reach courses from 70 to 80 degrees true wind angle. In general we have seen that modern Imocas with foils sail faster under these conditions, which can generate a lot of righting moment, which in turn leads to more power and speed. The next thing to consider is Brazil's most easterly point, Recife. The first boats are expected to pass Recife on January 15th. Due to the shape of the land and the prevailing eastern trade winds, there is a cushioning effect near the coast. This means that if you get too close to the coast, the wind can be weaker. In general, skippers should be at least 30 nautical miles from the coast to avoid slowing down due to the lighter winds
One day later, on January 16, the approach to the Kalmen follows at 1 degree south latitude. At this time of year the slacks generally don't cause too many problems and the fleet shouldn't be slowed down too hard. But beyond that, she still has the entire North Atlantic ahead of her, which will inevitably keep the race exciting until the finish line.