How To Sail Across The Atlantic

It's easy. Lots of folk do it. Assuming you already have a fair degree of sailing skills and a suitable boat, crossing the Atlantic under sail is just a matter of when, and from where, and in what direction.

Let me explain.

The Atlantic – by which, being a Brit, I mean the familiar expanse of water north of the equator – is roughly 3500nm (nautical miles) wide at its maximum. It's fringed to the east by Europe and north-western Africa, and to the west by the Americas, north and south. And, at just below  its widest point lie the West Indies, a string of islands that play guardians to the Caribbean and are a renowned magnet for sailors of every persuasion. They are also the most popular landfall for boats sailing east to west – a voyage there from the Canary Islands being about 2,700nm.

Popular, did I say? How so? To get to the Canaries from the UK would involve a trip of 1400nm, bringing the whole transatlantic journey up to an epic 4000nm. When Newfoundland lies just half the distance to the west, where's the sense in that?

Ah… I take the point but actually it's very sensible indeed. To explain why, I have to be very British and talk about the weather – weather on a global scale, that is. You see, the North Atlantic basin is dominated by an area of high atmospheric pressure parked approximately slap in the centre. If it drifts over the Azores, a little to the east, it's called the ‘Azores High' and if back west over Bermuda, the ‘Bermuda High' – all very logical if a tad proprietorial.  However you label it, it's a doggedly permanent feature, rarely likely to wander far. And its influence is profound.

We humans tend to think of winds as surface phenomena whereas they are very much three dimensional in nature. Hot air ascends in tropical regions, cools at high altitude, then descends again as it meets much colder air nearer the poles. This churning of the atmosphere drives what we know as wind.

To describe what happens next we need to acknowledge the 19th Century physicist Gaspard de Coriolis lent his name to the ‘coriolis effect' – the workings of which he was the first to explain. It's all to do with the Earth's rotation but that's a whole other subject. To be brief, the coriolis effect determines the way the prevailing winds circulate around areas of high atmospheric pressure – namely, always in a clockwise rotational direction in the northern hemisphere and counter-clockwise south of the equator. Incidentally, the reverse is true for ow pressure systems.

The general circulationaround the Azores High means that inhabitants of the UK can expect predominantly westerly winds, the Portuguese will see northerlies, sailors sailing westbound towards the Caribbean will enjoy easterlies (the trade winds as they are appropriately known) and those on the Atlantic coast of the United States will be very familiar with southerlies. But there's more. The friction between these prevailing winds and the waters over which they blow sets up ocean currents that flow in the same direction. In short, the whole system becomes a giant carousel of wind and water rotating majestically around the Azores/Bermuda High.

Mariners have known this for centuries and are well accustomed to harnessing these forces to their advantage. Their experiences are well recorded and have trickled down to the present day.

So, let's imagine a sailboat planning to explore both the US eastern seaboard and the Caribbean. How might the skipper plan his or her itinerary? Logic might seem to indicate that they should set the much shorter route directly for Newfoundland and then head southwards down the US eastern seaboard, eventually to the West Indies.

Good plan? Absolutely not. This would have them battling both headwinds and current every inch of the way – an undeniably miserable experience -- with a very real possibility of damage to both boat and crew.

No, the skipper concludes. Better by far to heed the voices from the past and hitch a ride on that well-intentioned carousel, allowing it to carry them around in style.

But when?

This is an important question. Late summer heralds a rumbustious time in the Atlantic. Spawned by the seasonal heat, deadly hurricanes brew in the lower latitudes. No place for a small boat at that time, no sir. Even further north, smaller but not insignificant depressions curve in from the west, borne by the carousel. It's not until late November that things really calm down and become more predictable.

By which time it's getting cold in the UK and the daylight hours are short. Musing on this, our skipper thought there must be a better plan.

And there is!

The eventual decision involved leaving British waters in June and spending a leisurely summer cruising the French, Spanish and Portuguese coasts – no hardship, I can promise you. Next comes the first longish leg from Portugal to Madeira (470nm) or the Canaries (570nm) or, of course, you could visit them both in sequence.

Wherever or for how long they dally, they will try and get to the Canaries by October. This should give them a couple of months to get some well-earned rest, square away their boat, get the provisions properly stowed, and generally prepare for the great adventure.

And the navigation from thereon? Well, the ancients had advice for that as well:

"Head south until the butter melts, then turn right."