A group of training lifeguards swimming off New Zealand were protected from a great white shark by dolphins. The lifeguards were training at a beach near Whangarei on the North Island when they were menaced by a 3-metre shark, before the dolphins raced in to help. The dolphins surrounded the swimmers for 40 minutes before they were able to make it safely back to the beach.

Marine biologists say such altruistic behaviour is not uncommon in dolphins. One lifeguard said that it was an uncomfortable experience, as they were circled by a great white shark, which came within a couple of metres, but the dolphins suddenly appeared and herded the swimmers together. The dolphins then swam in tight circles to create a defensive barrier as the great white swam beneath the surface. The swimmers said the dolphins were extremely agitated and repeatedly slapped the water with their tails, presumably to try to deter the predator as it cruised nearby.