CAPE AGULHAS – WHERE GREAT OCEANS MEET
An intergovernmental institution, the International Hydrographic Organisation (IHO) was founded in 1921 to establish, inter alia, the boundary between the Indian and South Atlantic Oceans. This was set as a line from Cape Agulhas southward, along the meridian of 20 degrees east, to the Antarctic Continent. This ruling is official and binding because South Africa is a member state of the IHO.
The meeting place of ocean currents is, however, a completely different matter: The Mozambique/Agulhas Current brings warm water from the tropics down the east coast of Africa. From the region of East London, due to the widening of the continental shelf, the current moves further off shore and the coastal waters become cooler. The main body of the current continues far into the southern seas, but, depending on the direction of the wind, it is often blown closer to the coast and parts of it can even drift as far as Cape Point.
The cold Benguela Current in the Atlantic Ocean comes up from Antarctica, and brushes the West Coast of Africa below the equator. The two currents, Benguela and Agulhas then meet and mingle to the south of Cape Agulhas and Cape Point in an area measuring hundreds of square kilometres. However, judging from the sea plants, especially the kelp that prefers cold water and which grows prolifically on the West Coast, the Benguela stretches past Cape Point and Hermanus but not much further than Cape Agulhas. The warmer temperature of the water in False Bay is caused neither by the Agulhas Current nor the Indian Ocean, but because it is not affected by the currents to the same extent as the waters further to the east. Furthermore, the lighter colour of the water is because the bay is shallow and has a sandy bottom.
However, it should be understood that the currents and sea life are of no relevance in determining the meeting place of the two great oceans. This is set in stone and is always at Cape Agulhas.