Over recent years an increasing number of yachts have made the passage directly from Cape Town to Europe without going via the Caribbean, writes meteorologist Chris Tibbs
There are a number of advantages to doing this, as well as saving around 3,000 miles of sailing, but the passage from the doldrums is predominantly upwind against the trade winds.
Some of the gain in distance will be lost in the extra miles sailed from being hard on the wind. However, this also needs to be offset against the fact that few passages sailing from the Caribbean to Europe are on a direct course as routeing takes us around the Azores High, with most boats stopping at the Azores.
Weather in the South Atlantic mirrors that in the North, with sub-tropical high pressure driving the trade winds of both hemispheres. On the pole side of the highs are disturbed westerlies, where depressions cross the Atlantic from west to east bringing fronts and stronger winds.
Between the high pressure centres are the doldrums, which we usually refer to as the ITCZ (Inter Tropical Convergence Zone). This is the area where the south-easterly trade winds of the southern hemisphere meet the north-easterly trade winds of the northern hemisphere.
The ITCZ can also be described as the thermal equator of the world. It follows the sun to the north and south, depending on the season, but generally lagging behind it. Despite following the sun, the movement of the ITCZ is not as extreme over the sea as it is over the land, and generally stays north of the equator on the eastern side of the Atlantic.
The ITCZ is a product of converging trade winds, and where we get convergence we will also get rising air. Add the heat of the sun into the mix and we get a band of large cumulonimbus clouds producing the typical doldrums conditions of light winds and squalls.
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In general, the ITCZ is narrower on the western side of the Atlantic and wider on the east with a fairly large triangle of more variable wind close to the African coast. This is why round the world racing yachts and record attempts, cross into the southern hemisphere close to Brazil, then get south of the high pressure before heading east.
It is also why there can be significant gains and losses coming back up the Atlantic after Cape Horn as racing yachts try to minimise the distance sailed while keeping in the strongest and most favourable wind – not an easy job.
The route from Cape Town to the Caribbean is relatively straightforward, although it is long. It usually sees trade winds all the way except for when passing through the ITCZ. This is best done near the north-east corner of Brazil where the light winds zone is generally quite narrow and the currents are also favourable making for fast passages.
With St Helena, Brazil and the islands of Fernando de Noronha on the way it is a pleasant passage and as the South Atlantic is hurricane free it makes an easy transition from the southern hemisphere summer to northern winter. This also ties in with most round the world cruises and rally schedules, as we need to be away from the Indian Ocean tropical cyclone season, which starts in November.
Together, this makes Cape Town a natural Christmas break point before continuing north. It also brings us to the Caribbean ready for a return to Europe before the hurricane season starts in June.
But not everyone can neatly fit into this timetable. Back in 2000-2001 the BT Global Challenge raced from Cape Town to La Rochelle, which was the first time I looked at this route in detail. Since then I have provided weather support for an increasing number of yachts on a direct passage to Europe – yachts built in South Africa to be sold in Europe, and owners that either don’t want to go to the Caribbean or whose schedule doesn’t fit in with this route.
Heading north from Cape Town is the same if heading direct to Europe or to the Caribbean as we are in the southerly or south-easterly trade winds driven by the St Helena High. These will generally hold (although they tend to back) all the way past St Helena to Ascension Island. The winds tend to be quite strong in the south but will ease further north, and can be very steady in speed and direction.
North of the Ascension Islands is the ITCZ; precisely where depends on the time of year but tends to be north of the equator. On the eastern side of the Atlantic this can be a wide band of variable wind sometimes from close to the equator to 10°N or even further north in mid-summer. Statistics show that close to the African coast the wind can come from any direction and there is likely to be some thunder.
As we move into the ITCZ it’s worth trying to set up for the north-easterly trade winds; the further east, generally the better the wind angle as you leave the ITCZ. However, this will be restricted by how comfortable you are in closing to the coast in this area. Personally I’d stay at least 200 miles offshore.
Once out of the ITCZ the approach to the Cape Verde Islands will be hard on the wind on starboard tack. A few port tacks may be necessary depending on wind angle and how hard you beat! The Cape Verde Islands are realistically the only place to refuel and provision. Then you are ready for the hardest part, heading into the trade wind belt.
The trades do vary and it may be worth waiting for them to ease, but if you delay for perfect conditions you’ll be waiting a long time. Although you could find lighter wind close to the African coast, from the Cape Verde Islands to Europe will entail a long starboard tack towards the Azores some 1,300 miles away.
I’ve had some yachts make for the Canary Islands, but this generally entails a lot of motor-sailing into the trades and Canaries current. I did see the track of one boat that beat to the Canaries; the tacking angle was not good and this was a boat that beat well, but with adverse current, big seas, and leeway it was disappointing progress.
So we’ll normally have to sail hard on starboard tack until into the Azores High, or into the westerly/south-westerly winds on the north of the High. We can usually turn east before the Azores if heading to the Mediterranean, however the Azores is a good place for a break and a bit of a recovery. From there, the rest of the passage will seem easy!
The Azores High will generally be a little further south in the northern hemisphere winter, so too will be the ITCZ. At the same time the north Atlantic storms and cold fronts will extend further south and will be more aggressive, which will displace the trades to the south. However, the Azores can see some very strong conditions before April, with a 6-8% chance of gales in March, dropping to 1-3% in May.
So when is the best time to go? My suggestion would be to aim to be in the Azores after the beginning of May and before the increasing chance of Cape Verde hurricanes in July.
The later you leave it the further north the ITCZ is expected to be, making getting to the Cape Verde Islands easier, but the trade winds north of the Cape Verde Islands tend to increase from about mid-June.
The direct route
- A shorter distance and faster passage
- Allows a wider departure time from Cape Town with the main risk of hurricanes reduced to a few months near the Cape Verde Islands
- Arrival in the northern hemisphere winter can be managed by staying south of the Azores
- Hard on the wind from north of the ITCZ, to probably near the Azores
- Beating into the trade winds is never easy
- You will sail against the Canaries current in the north Atlantic
- A lot of motoring through a wide ITCZ
There is the alternative of passing west of the Cape Verde Islands, heading north-north-west towards the centre of the Azores High, but this will give a long passage without breaks and would require greater care for hurricane season.
The real question is how will your boat, and crew, take to a hard beat?
Cape Verde hurricanes
In the North Atlantic the hurricane season starts in June and lasts until November. On this route we are generally east of Atlantic storms but there is the possibility of Cape Verde hurricanes. These are hurricanes that develop close to the Cape Verde Islands or even between the Cape Verde Islands and Africa, before tracking west across the Atlantic.
They’re not very common and will generally be late in the season, however particular attention needs to be paid to the forecasts from June onwards as the possibility of Cape Verde hurricanes is one to be taken seriously. Typically Cape Verde hurricanes are most likely in August and September but there have been some in late July and October. North of the Cape Verdes hurricanes are not likely, unless you are a long way west.
First published in the October 2020 issue of Yachting World.