The descent of the Atlantic… three weeks
The northern Atlantic
In November, there is generally a disturbed W’ly air flow in the northern hemisphere, in which lows circulate, sweeping across France and Great Britain. And despite popular thinking, the Bay of Biscay is the most likely place to have the strongest winds of the Vendée Globe.
Two scenarios can present themselves: either the solo sailors will have to negotiate the passage of a cold front and will begin their circumnavigation of the globe in some harsh conditions, without a sizing-up round. Or the Azores High will be a little further north than usual, which would generate NE’ly winds; a second hypothesis synonymous with a rapid downwind start to the race.
Cape Finisterre, the approach to which is renowned for being pretty lumpy, marks the start of the hunt for the tradewinds of the northern hemisphere (NE’ly air flow), which should accompany the sailors as far as the Doldrums. A fairly rare alternative to this is nonetheless a possibility: if a stormy low forms between the Canaries and the Azores, it can come and upset the tradewind air flow with S’ly winds, and make the descent towards the equator long and laborious.
The Doldrums
Referred to as the Doldrums by sailors, the meterological terms used is Inter-Tropical Convergence Zone (ITCZ). Dreaded for its random nature, this band of low pressure lies between the equator and 4° north. This zone is created by the opposing forces of the tradewind in the northern hemisphere (NE’ly sector) and those of the southern hemisphere (SE’ly sector), and it is synonymous with shifty winds and conditions alternating between calms and violent squalls.
The southern Atlantic
The exit from the Doldrums is symbolised by the arrival of the tradewinds from the southern hemisphere. This steady SE’ly air flow will rapidly lead the solo sailors towards the coast of Latin America.
Level with Salvador de Bahia, in Brazil, the sailors will have to cross a ridge of high pressure, stemming from the Saint Helena High, which will enable them to set off downwind for the second stage in the rounding of this zone of high pressure. Saint Helena is a large zone of high pressure which stretches across a third of the southern Atlantic. Most frequently positioned where you might expect it to be, it can nevertheless play tricks and be mobile. At this stage in the race, the solo sailors can attempt some tactical coups. Indeed, if during their passage a front comes along and causes interference with the anticyclone’s north-western ridge of high pressure, the sailors can attempt to exploit this situation and ‘cut the corner’. The upshot of this is an extremely advantageous time-saving. The rounding of Saint Helena and their exit from it are crucial for the next stage in the race as it is imperative to be in the first wagon to stand a chance of victory. After over 7,000 miles spent in the Atlantic, the solo sailors prepare themselves for entering the Indian Ocean. This passage is marked out by the Agulhas Cape, at the southern tip of Africa.
The Southern Ocean, the tour of the Antarctic… A month and a half
The Indian Ocean and the Pacific Ocean
The solo sailors in the Vendée Globe venture into the Southern Ocean during the summer in the southern hemisphere, the most favourable time of the year for such navigation. During their loop around the Antarctic, measuring around 10,000 miles, they traverse the Indian Ocean and then the Pacific Ocean.
The Deep South is characterised by a succession of austral lows, which move from west to east, with a ridge of high pressure significantly slowing the progress of the fleet. At a given point, there can be between five and nine lows chasing each other around the Antarctic.
In the fronts, the sailors will have to deal with average winds of between 30 and 50 knots, gusting to 50 or 80 knots. The seas here are always big, with average waves of 5 to 6 metres for the less active fronts, stretching from 9 to 12 metres for the most active zones. Nevertheless, the winds and the seas are orientated in a favourable direction for the fleet to make headway.
The proximity of the Antarctic causes very cold temperatures and the visibility is often less than 10 nautical miles throughout the majority of the big loop.
The Cape Horn
The passage of Cape Horn, at the southern tip of Latin America, marks the end of this long period. A narrow but compulsory passage, the Horn has built its legend on the storms which sweep across the surrounding area. The lows, which have found no resistance to their movement throughout their course around the Antarctic, have just slammed into the Andes and end their journey level with Cape Horn.
The climb up the Atlantic… three weeks
The southern Atlantic
Off Argentina lies a new zone of disturbances, but this time their source is storm related: the pamperos. These can give rise to some very violent winds. Indeed this is where Ellen MacArthur hit 70 knots of wind in a stormy squall, during her solo record around the world in 2005. From a strategic point of view, it is during this climb towards the Brazilian coast that you can lose the race.
The Doldrums
The solo sailors will cross the Doldrums once again but this time to the west where it is less active. This passage will thus prove less tricky than during the descent, but it can still slow the fleet.
The northern Atlantic
By the end of January the solo sailors are back in the northern hemisphere, after being away for over two months. Special attention will go into their negotiation of the passage of the Azores, especially in the event of rivals being close by. Indeed the first to touch the disturbed W’ly wind will gain a great advantage on the road to victory, even though the Bay of Biscay can still disrupt the established order.