The sea off Cape Agulhas is notorious for winter storms and mammoth rogue waves, which can range up to 30 metres (100 ft) high and can sink even large ships. Over the past few hundred years it has been believed that around 150 ships have sunk around Agulhas. These conditions are caused by a number of factors. The naturally strong winds of the roaring forties, which blow from west to east, and the cold Antarctic Circumpolar Current flowing in the same direction, come up against the warmer Agulhas Current in the region of the cape. These conflicting currents of water of different densities, and the west winds blowing against the Agulhas Current, can create extremely hazardous wave conditions; these are further exacerbated by the shallow waters of the Agulhas Bank, a broad, shallow part of the continental shelf which juts 250 kilometres (155 mi) south from the cape, after which it falls steeply away to the abyssal plain.
These hazards have combined to make the cape notorious among sailors. The coast here is littered with wrecks: Arniston (1815), Cooranga (1964), Elise (1879), Federal Lakes (1975), Geortyrder (1849), Gouritz (1981), and Gwendola (1968) are just a few of the vessels lost in the proximity of the “Cape of Needles”. Owing to the hazards and following the loss of several vessels, notably the Arniston, a lighthouse was built in 1848. The lighthouse now plays host to a museum and a small rustic restaurant.