(dolphins splashing) - [Narrator] Of all the relationships found in the ocean, few can beat the spinner dolphins.

As well as gathering in huge numbers, they are the acrobats of the dolphin world.

(dolphins splashing) They can leap over 10 feet high and spin seven times in a jump.

(dolphin splashes) (dolphin whirling) (dolphin splashes) Today, they're on a hunting expedition.

(dolphin splashes) Spy Dolphin is here to find out how they work as a team.

(water splashes) (dolphin whistles) Their bubbles provide a clue.

On closer inspection, they plainly come from the dolphins blowholes.

(dolphins whistling) A sign they are whistling to each other.

(dolphins whistling) They use these calls to bring the pod together.

(dolphins whistling) They also have a unique whistle to announce who they are.

The dolphin equivalent of a name.

(dolphin squeaking) (water bubbles) (dolphins whistling) As well as whistles, they use clicks to communicate too.

Some clicks are ultrasonic, far above our hearing range.

All this works at close range, but to contact dolphins far away, they use their corkscrew leaping.

For an aerial view of what's going on, Spy Frigate films from above.

(water splashing) The leaps can be seen by distant dolphins, (dolphin splashing) while the splashing can be heard from far and wide.

(dolphins whistling) United, they can hunt as a super team.

(dolphins whistling) Our spy is in the midst of an extraordinary gathering: One of the greatest mega pods ever filmed.

(dolphins whistling) Spy Dolphin is here to witness this astonishing moment.