The annual sardine run is a migration of pilchards (not actually sardines) from the Cape, following the cool water up the coast, as the Mozambique Current swings out to sea. Now a sardine migration sounds pretty – well – mundane, until you realise that these delicious little fish will be followed by an enormous concentration of dolphins, sharks and game fish, and enormous flocks of diving, guzzling seabirds.
Now diving the run is pretty tricky, as these little fish - and the bigger ones following them - are not that predictable. So dive operators base themselves in a convenient spot - either on the Wild Coast or the KZN South Coast. Most will go out every day, and some have microlights that scout the sea looking for large shoals. When a likely-looking shoal has been spotted, the group moves off to the nearest launching site and heads out to sea. This is not a good trip for those prone to seasickness - it's not your average sprint out to a dive site. You could end up being at sea all day. The holy grail of diving the run - what everyone is after - is a bait ball. Schools of, literally, thousands of common dolphins herd the sardines towards the shore, and sharks, marlin, tuna, other dolphins, Bryde whales, Minke whales, Sei whales, and other game fish may join in the feeding frenzy. And, from above, hundreds of seabirds – mainly gannets, gulls and shearwaters – divebomb the shoals in what looks like the re-enactment of a World War II movie with shadows of Alfred Hitchcock. And then they sit on the sea to rest in great rafts – too full to take off. This phenomenon was well documented on the BBC’s “Blue Planet”.
An added bonus is that the sardine run often coincides (with no causal relationship) with the northward humpback whale migration, so the sea is literally bustling with life.