The Agulhas Current

Sailing in strong currents can be very exciting. One example is undoubtedly the voyage southwards in the Mozambique Current, which then becomes the Agulhas Current.

This large oceanic river, running south along the east coast of Africa, can increase the speed of a boat sailing in the same direction by additional 2-3 knots. Sailing can be a pure pleasure, provided, of course, that you are sailing downwind. Even a strong wind if it is blowing from the north is not a major problem for high seas vessels. The situation changes dramatically though when the wind turns around and starts blowing from the south, i.e. from the opposite direction to the current. A weak southerly wind may make sailing but a little more unpleasant on swaying seas but one that reaches 30 knots and more is able to stir up dangerous conditions for any vessel caught in a clash of the wind and a strong counter-current. Many yachts, including a few Polish vessels, have already discovered that. Some, having collided with an unusually high wave a relatively short distance from Cape of Good Hope, were forced to abandon the voyage.

Personally, I am particularly careful when sailing in such conditions, since a storm has struck our yacht on the way from Brisbane to Sydney before the Sydney-Hobart race in December 2014. Back then, the wind which was blowing at a speed slightly below 40 knots, upon meeting the East-Australian Current, created extremely steep waves. We were crashing down the wavetops with great impetus, each time hitting water as if it had been concrete. Reducing yhe yacht’s speed to 3 knots did not help. Never before and never after has Katharsis II been battered so badly. Even the heavy storm we struggled through a few months later in the Antarctic Ross Sea, with much stronger winds and ice all around us, did not give us such a hard time.

I sailed in the Mozambique Channel on the previous occasion exactly one year ago in a crew of two with Hanna Leniec and myself. Sailing from the Seychelles to Cape Town, we decided to run along the centreline between Madagascar and Mozambique, where the current is not as strong as it is along the coast of Africa. Without much trouble we weathered two storms. A third one caught up with us 40 miles from the coast. I decided then to sail relatively close to the shore on the continental shelf, i.e. in the waters less than 200 metres deep. There, there are almost no sea currents and the waves are far less dangerous. Sailing close to the shelf boundary with the possibility of quickly escaping into the safer coastal waters seems to be the safest tactic when sailing south.

I have now chosen a different route and we crossed the Mozambique Channel towards Africa along the 18th parallel. The navigation tactic had to take into account the clash between the Mozambique Current and strong winds from the south. This forced us to stop first in the lee of the Bazaruto Islands and then in Maputo Bay near Inhaca Island. We decided to wait out at the anchor an extensive high-pressure area which began to engulf the entire area of the Mozambique Channel. It carried cold air from the Southern Ocean. Usually we associate high-pressure areas with sunny weather. Here, the high pressure clashed with warm air masses which brought us 2 days of rain and southerly gale.

Waiting for the passage of the weather front, we made use of the last warm rays of sunshine in this voyage. We also supplied our pantry with fresh fruit and vegetables which we bought at the market in the only village on Inhaca Island. The arrival of the front caused a temperature drop from over 30°C to barely 18°C. In the sheltered bay, the wind created a cauldron. The anchor worked hard, producing painful sounds for the ears but it held fabulously. Katharsis II was nervously jerking on choppy waves, but we were safe.

After a few days of leisure, on Sunday, October 28 at 06:00, we raised the anchor. The wind calmed and we could safely guide the yacht through the shallows of the Bay of Maputo. The centre of the high-pressure area had moved over Madagascar and after a few hours the wind started to turn to the north. We slowly sailed on a still swaying sea. In the night, the wind stiffened and soon was blowing full force at a speed up to 40 knots. This allowed us to sail very fast south in spite of the sails reduced to the minimum. The Agulhas current now became our ally, thanks to which the speed of the yacht rarely dropped below 11 knots. Abeam of Durban, the wind started to calm. Surprisingly, the current also decided to turn. Such turbulences of current unfortunately happen from time to time. They caused a significant swinging of the sea which battered the boat and caused the sails to flatter. In order not to damage the rigging we were forced to reef.

The Agulhas current can be of help but it can also be very annoying, too. However, it definitely makes sure that sailing in its area is one of the most demanding and exciting and certainly not boring.

Best regards from the deck of s/y Katharsis II, southbound.

Mariusz Koper + crew of Katharsis II