GREAT BARRIER REEF? It's even better than that.

When you're peering across acres of coral in the shallows 70 km out to sea off the coast of Port Douglas, you realise that it's not called the Great Barrier Reef for nothing. A short distance away, the energy carried by the South Pacific collides with Australia's continental shelf. This is irresistible force meets immovable object stuff. And yet, somehow, we're bobbing about peacefully unawares of the battle playing out across the coral barrier nearby.

Snorkelling here can be mesmerising. Eyes up, gazing forward through a thin film of water separating life below from life above. Making yourself as skinny as possible to avoid scratches and cuts from the coral. Drifting over those sharp, corally fingertips reaching for the surface, making the gentlest movements with your flippers to keep yourself in slightly deeper water before the coral and ocean floor suddenly falls away leaving you soaring across an ever darkening depth. Your gasp exaggerated by the snorkel pressed beside your ear.