South Africa has 1,699mi (2,735km) of coastline along the Atlantic or the Indian Ocean. Most scuba diving sites are in KwaZulu Natal between Cape Town and Port Elizabeth on the way of several migratory routes including the gigantic sardine run going up the coast every year. The wealth of the underwater biodiversity is due to the diverse marine areas that combine Indo-Pacific and Atlantic species. The warm ocean currents of the East Coast also carry a wide variety of tropical fish. The 31mi (50km) reefs of Sodwana Bay shelter 95 species of coral and 1,200 species of fish among which various rays, the spotted moray eel or the very red Cephalopholis sonnerati. According to Nelson Mandela, South Africa is the only place in the world where the oldest and largest mammal (rhino/elephant), the oldest fish (coelacanth) and the largest marine mammal (whale) coexist.