Builders - S1.E1

In this first episode, David descends beneath the waves at night in the state-of-the-art Triton submersible, the first of its kind to visit the reef. He meets some of the tiny coral animals that built the reef and helped to turn it into an underwater wonderland. He then takes to the skies to witness the vast scale of their endeavour, a living structure that provides a home for thousands of species.