Complex sentence: The currents of the two oceans meet at the point where the warm-water Agulhas current meets the cold water Benguela current and turns back on itself--a point that fluctuates between Cape Agulhas and Cape Point (about east of the Cape of Good Hope).
Split into simpler sentences: The currents of the two oceans meet at the point where the warm-water Agulhas current meets the cold water Benguela current and turns back on itself. That oceanic meeting point fluctuates between Cape Agulhas and Cape Point (about east of the Cape of Good Hope).