Global Challenge
Week 32 - Into the South Atlantic

Whenever you are tempted to head out to sea, it always pays to check the weather forecast. You might expect such advice from a professional forecaster, who is taking part in the Global Challenge yacht race, and is also posting this gem on the BBC's comprehensive Weather website. My own experiences, not only of the past seven months, but in just the past three days bear witness to the quality of this advice.

A cursory glance at a synoptic chart for the waters to the west of South Africa would have shown high pressure persisting for five or six days from our date of departure. Tick that box and on to the next pre-departure task then? Well, not quite. If you've followed my journey, you'll remember how varied the conditions have been.

Much of the truly dramatic weather has come from vigorous areas of low pressure, bringing gales and high seas. Some of the more demanding sailing and forecasting conditions though have come when our track has taken our team close to areas of high pressure, such has been the case over the past few days. High pressure forms to the west of South Africa during the summer then tends to migrate around the Cape of Good Hope to form another pressure centre to the east, this cycle repeats itself to bring prolonged spells of fine, dry weather.

Pressure charts for race start day showed that Cape Town was likely to experience light winds and so it proved. The fleet of twelve, 72ft yachts crossed the line doing little more than 1-2kts. It was only after half an hour or so that the breeze developed and our team was one of the first to round Robben Island and head northwest towards the distant Equator.

Once clear of the shadow of Table Mountain and out into more open waters, so the wind on the eastern flank of the high really began to pick up. With spinnakers flying and a rolling swell from astern, speeds of 16kts were commonplace, and well in excess of our normal cruising speed of 8-9kts. These conditions prevailed for much of the first two days, allowing my team to log over 500nm. Having taken more than that cursory glance at the forecast, however, I knew that a dramatic change awaited us further north.

Through day three, the southerly winds eased to a point where, whatever our sail combination, we were unable to make any real progress. Although the high centre was well to our west, the gradient wind was so light that the sails were unable to move our 43 tonne yacht.

Even more disappointment came when our competitors' positions were reported. An extra knot or two of wind kept them on the move to the east of us, dropping us from second to seventh in just a few hours. Even through the early hours of day four, minor fluctuations in wind caused our speed to range from nothing to nearly 6kts, all of this from a synoptic pattern that had shown little overall variation.

If your sailing, therefore, takes you from Littlehampton to Largs, or around the world, do pay very close attention to the forecast. My next real test will come in the Doldrums, yours may well be much closer to home.