A distant barn door - perhaps

For the non-sailors and the meteorologically challenged: the weather in the central South Atlantic tends to be dominated at this time of year by a high pressure system that is centred broadly south of St. Helena. It stretches across from the S. American coast almost to Africa and sometimes down to about 35 south at its biggest. We won't go into why it's there and definitely not into coriolis force but a high in the southern hemisphere is a system in which air descends from the upper atmosphere and radiates outward from the centre in an anti-clockwise direction. There is always a soft windless patch in the centre. That means that the wind on the western side of it blows down the S American coast from the north or north east and on the other side, up the African coast from the south. Along the southern edge, it blows from the west, roughly along latitudes 25-30 south.

It follows that to get from the NE corner of Brazil(where we were a week or so ago) across to Cape Town, it is much easier to head south or SSE down the western edge of the high and turn left or east as you get towards the southern edge, taking advantage of favourable winds all the way. If you try to take the straight line you are likely to be heading into the southerly wind on the eastern side - and also the Benguela current which flows north up the African coast. We are now trying to smooch the best course from here to the Cape by cutting the corner around the south western edge of the high but not losing the wind by getting too close to the centre. This big arc is also closer to the great circle or shortest distance across.

Sailing to Australia by this route has its inherent penance. A bit like an out and back marathon, where the entire first half is sheer brain and tissue damage just getting you to the turn around point, you set out from Falmouth for Australia by going south west to get around West Africa and the effective turning point as you pass west of the Cape Verdes at about 27 W. And then you have to go a long way east to get the best angle to cross the convergence zone and the SE trades - a zig and a zag so far, plus another zig to get across and down to the base of the S Atlantic high which is what we are doing now. But - big but - yesterday morning I now think it safe to say, grabbing the nearest bit of wood, we made the final turn for home and we are heading SE towards Tristan da Cunha and the base of the high. Yeeebloodyhaaa! And so far, nothing difficult - just 'orrible in the CZ and uncomfortable for the arse bone down here. We may still have to trek a bit west on the way, to adjust our course around the high but I think we're looking towards a very distant barn door south of Hobart.

Appendages please, everyone!