Visiting the Great Barrier Reef in a boat and diving among the waters with the fish and coral is such an exhilarating experience. It is the world’s largest reef system and has over 1,500 species of fish. In fact, it supports 10% of the world’s fish species. The reef is very ancient and is made of living coral growing on dead coral. It is composed of over 2,900 individual reefs and has over 900 islands stretching 2,600 km. It is so large it can be seen from outer space.