living and dead coral. Coral reefs exist in warm climates with clear salt water and lots of sunlight.And since coral reefs are also in shallow water，you can actually see them from above the water！All along the Great Barrier Reef，the color of the coral reef changes，as does the color of the water，which varies from a green to a blue color. The best way to experience the magic and beauty of the Great Barrier Reef is to experience it up close and personal，underwater.People who have dived and explored in the Great Barrier Reef claim that it is an under­water wonderland filled with amazing creatures and beautiful sights.