A few nights after the November full moon, when the water temperature and tides are in exactly the right phase, one of the most extraordinary events of the natural world can be witnessed. This is a synchronised dance that happens at precisely the same time along the entire 2,000- kilometre length of Australia's Great Barrier Reef. As if on cue, a vast array of coral species prepare to cast their tiny eggs and sperm into the surrounding water. At this very moment, the ocean begins to resemble an upside down snow storm as a blizzard of coral gametes are released and gently float to the surface and drift away in the currents, colonising reefs as far as the eye can see and beyond. Australia's Great Barrier Reef is exceptional in its biodiversity, with more than 1,500 species of fish, and countless species of corals and other invertebrates. This visually spectacular film shows how distinctiveness of colour and pattern has become essential: from the giant moray eel which keeps its colours for a lifetime, to angelfish which change colour as they transform to adult, through to parrot fish that have very different colours during the day compared to that of night. Adaptation amongst the fish has evolved: fairy basslets and anemone fish for example can change sex according to whether a dominant male or female is needed. Every organism HERE has developed its own special effects for survival. We also look at the Grey reef sharks - the wolves of the reef - and the Humpback whales who visit the Coral Sea each winter, taking shelter in the protected shallows to rest and give birth. More than 90 per cent of the world's coral reefs have felt the ruinous affects of human habitation and have so badly deteriorated, some may never recover. This definitive film on the coral reef, shot in vivid HDTV, offers a rare chance to visit this beautiful and pristine wilderness to see just how the Great Barrier Reef was formed and the secrets of how animals utilise special effects to increase their odds of survival amongst the coral.