Great Barrier Reef, Australia
The Great Barrier Reef is a series of interlocking reefs and islands that stretch for over 2000 km in the waters off the coast of Queensland, Australia. It is the most extensive coral-reef system in the world, and the largest structure made completely from living organisms: tiny coral polyps. Between 50 km and 300 km away from the shore, the reef comprises more than 2500 individual reefs (strips of rock or coral) and 600 islands.
There are basically three types of island: continental islands (the peaks of sunken mountain ranges), sand islands and coral cays. Many of these islands have coral reefs nearby or even mini-reefs fringing them, but Heron Island and the near'by Wilson Island are unique in that they are true coral cays that offer accommodation and actually form part of the reef. This means that you can simply swim from their beaches to dive or snorkel on the Great Barrier Reef itself.
The diving around Heron Island is reputed to be some of the best on the whole reef, attracting people from all over the world. Wilson Island is administered by Heron, and just 10 people are allowed to stay on it at anyone time. Those with a scientific interest in the reef can stay at the research centre on Heron Island, which is run by the University of Queensland. From ground level, the barrier reef appears unexceptional. The sea might be a luxurious blue and the islands sandy beaches creamy white, but little else is revealed unless you go up or down. From the air the true extent and colours of the Great Barrier Reef become apparent. Within waters of the purest turquoise, reef after reef seems to stretch away as far as you can see, and dotted around are tiny, white-fringed coral cays surrounded by their own reefs.
Diving or snorkelling on the reef is a truly magical experience, and no superlatives can do it justice. Ifs like experiencing a completely new world, where sight is the only sense you need and gravity seems irrelevant. Stick to shallow waters if you want to see the colours clearly, as deeper water filters out most of the red and green wavelengths, giving everything a deep blue tinge. The coral is home to a wealth of life forms: multicoloured fish dart around at lightning speed, while green turtles and loggerheads take things at a more leisurely pace.
At the top of Heron Istand, in the aptly named Shark Bay, you will have a very good chance of being able to swim with the small and relatively friendly reef sharks.
You don't always have to go beneath the waves to see marine wildlife. Coming back from Wilson Island by boat, I came across a couple of migrating humpback whales. In the shallow waters of this part of the reef they were unable to dive deep, so could hear them communicating with their haunting 'songs'. You are most likely to see migrating whales in September, while January and February are good times to see turtles laying eggs and the young eventually hatching.