Schooling Sharks: Aliwal Shoal, South AfricaThose who crave big-animal encounters know that South Africa has some of the world’s most shark-filled waters. While many divers are heavily into the cage diving operations around the Cape region, if you prefer not to be behind bars, try the rocky reef known as Aliwal Shoal, located about 30 miles south of Durban. Here, huge groups of sharks are known to arrange themselves in layers, sometimes three or four species deep. You might find a handful of hulking zambezis (aka bull sharks) lurking shyly at the bottom, a half-dozen gargantuan tiger sharks gliding in the water column and innumerable blacktips darting about at the surface like over-active terriers. Believe it or not — a dive at Aliwal with 50 tiger, blacktip and zambezi sharks swimming together is just an average day!