Geographers call them tabulars, but they have won since 1er February 1990 the nickname of “sinful” in the marine world, so much they are feared. During the first edition of the Vendée Globe (1989-90), the sailor Jean-Luc Van Den Heede had chosen to “Cut the cheese”, that is to say to go down very south to shorten the route to the finish (the round the world is shorter when you get closer to the poles).
It was bad for him, because he found himself face to face with a table 300 meters long and ten high, which he narrowly avoided. He then had to head due north, slaloming between debris of icebergs to escape the grip of the ice.
These tabulars, detaching themselves from Antarctica at the end of the austral summer, produce smaller blocks, which then disintegrate into growlers, large more or less translucent ice cubes, almost impossible to spot for on-board radars.
Already decimated by UFOs, unidentified floating objects, the Vendée Globe fleet, spread over 7,000 kilometers, has entered the Antarctic zone of the Indian Ocean, which it will no longer leave until Cape Horn. The organization drew an imaginary line there, called ZEA (Antarctic Exclusion Zone), made up of 72 points spaced 5 degrees apart (360 ° in all, i.e. the full circle of the earth), under which skippers are prohibited from descend, under penalty of penalties.
Maxime Sorel grazes the ice exclusion zone
→ DOSSIER: all the information on the Vendée Globe
On Saturday 5 December, the imprudent Maxime Sorel touched the line less than two kilometers away, not far from the Crozet archipelago (1). “He scared us very much”, explains race director Jacques Caraës, who would have had no other choice but to order him to turn around and then pass this famous line in the right direction, in dangerous sea conditions.
Was Maxime Sorel adventurous or just dizzy, like Jean-Pierre Dick, who had crossed it without realizing it in 2016? Or would he have simply forgotten to check his emails? The race management in fact warned by email at the end of last week that it had decided to go up the exclusion line compared to its low water level on November 8, the date of the start of the race.
130 satellites focused on the course
This decision is the result of collaboration between the organizer and a battery of engineers working for the CLS (Collecte localization satellite), a subsidiary of Cnes (National Center for Space Studies). “We cross-referenced information from 130 satellites, with 760 people working in various companies linked by contract to the organization, including 450 in France”, explains Sophie Besnard who coordinates the device from Toulouse.
If the tracking of the large tabulars at the time of their release is in the ropes of the satellites, their drift and their location when they fracture is more complex to follow. Hunting then becomes a computer business: after having spotted the large masses of ice in June, the engineers trigger a series of calculations taking into account the tides, the wind and the evolution of the water temperature. to identify potentially hazardous areas. This can lead to the modification of the ZEA.
Ice threatens Cape Horn
“After having to go up the line for Crozet, we had good news about the Kerguelen Islands and it is likely that the boats will be allowed to descend further south than expected, which will allow them to gain distance”, continues Sophie Besnard. At least for the head of the race because the last ones will undoubtedly have the door slammed in their face, because of a new cooling of the waters which will limit them further north.
There remains a concern about the last big obstacle of the course, Cape Horn, which the leaders will cross around Christmas. “We still have a lot of images and data to analyze, explains Sophie Besnard, but it is feared that the gateway between the Pacific and the Atlantic will be congested with ice. “ And therefore even more narrow and dangerous than usual.
The skippers are now engaged in the second zone – after the start – where we deplore a lot of abandonment. Boats and sailors tire and floating objects, icebergs, sperm whales or containers fallen from boats, are very numerous in these areas. After Nicolas Troussel, Alex Thomson and Kevin Escoffier, two skippers left the race in recent hours after hitting an unidentified floating object: the French Sébastien Simon and the Briton Samantha Davies. The latter chose to repair her boat in South Africa, which automatically disqualifies her, but plans to continue her world tour outside the race.