The great white shark follows the bodyboarder riding a wave and then spots the surfer sitting on his board waiting for another wave. He doesn’t appear to know the shark is approaching. When the surfer starts kicking his right foot in preparation to catch the wave, the sudden movement scares off the great white shark. It isn’t clear how the warning system works once a shark is spotted by a drone, or whether those riding waves in this video were made aware of the shark’s presence. But hopefully the system works.