This event takes place annually outside my home in South Africa. Massive shoals of sardines - some, kilometers long - migrate up the coast. The shoals are followed by dive bombing sea birds, predator fish and dolphins who break smaller ball shaped schools off the bigger shoals to gorge on fresh sardines.
Some day, I want to take some drone cams out there and shoot one of these shoals from above as I think it would provide another perspective on the diving sea birds.
Anyway, this footage is shot on my area of the coast by some divers. Excuse the music but the images are truly amazing, especially the sharks around the 7 minute mark.