Wonders of a waterworld

Brampton, Daydream, Dunk, Fitzroy and Great Keppel. These are just some of the Great Barrier Reef's evocatively named cays and islands that enthral millions of tourists every year.
Not only is the Reef a United Nations World Heritage listed attraction, but it's regarded as one of the seven wonders of the natural world.
It is larger than the Great Wall of China and the only living thing on Earth visible from space.
For a thrilling foray with the splendour of the reef take a trip to Green Island, a tropical cay just 45 minutes from Cairns.
Circled by white sandy beaches and luminous blue waters, Green Island is the picture-perfect island getaway.
For almost 50 years the island has been one of Cairns' premium tourist attractions.
This diminutive coral cay once had nothing more than a jetty, a marine viewing point, and a few scattered huts.
At just 15ha, Green Island can be effortlessly walked around in 20 minutes, making it an ideal destination for day trippers from Cairns.
Its circumference is 1.5km and it is is about 300m wide and 650m long.
The edges of the island are fringed in beautiful coral-sand beaches, and the interior is predominantly lush, green rainforest.
The recently developed hotel resort takes up only 12 per cent of the total island so, remarkably, there are still plenty of places where people can escape and find their own personal hidey-hole.
Green Island is home to 126 native plant species, a myriad birdlife, and surrounded by magnificent coral gardens.
Operating out of Cairns, Big Cat Green Island Reef Cruises whisks you across to the cay, with morning and afternoon departures.
In addition to the glories above water, be sure to take a thrilling excursion in the underwater world among the coral reefs.
The glass-bottom boat and mini-submarine excursions are the best way to soak up the splendour of the tropical fish, turtles, giant clams, starfish, shells, anemones, eels, sponges, sea urchins and many more amazing marine creatures.
If you are prone to claustrophobia, bear in mind that the mini-submarine is a tightly compact affair, not dissimilar to a tin of sardines.
One other equally pleasurable way to encounter the subterranean wonders is to snorkel or scuba dive.
Cruise operators have plenty of gear for hire, and will provide you with plenty of "how to do it" help, if you are a beginner.
What I particularly loved about Green Island is the ease in getting there, and the fact that it's barely above sea level.
Curl up on the beach, gaze out on the sparkling sapphire waters, and you will feel as if you are lying on top of the wide open sea.
TOP TIPS
* The Reef Casino Hotel is a fabulous place in Cairns from which to explore the delights of tropical North Queensland. It boasts one of Australia's finest boutique casinos, a spree of wining and dining options and 128 luxuriously appointed rooms. Unmistakably furnished in North Queensland style, the bright, stylish and comfort-plus rooms feature plantation shutters and light timbers. www.reefcasino.com.au
* BTS Tours offers a multitude of small-group quality tours and personal transfers, enabling you to hop-scotch around the region with affordable ease, expertly guided commentary and no shortage of wry Aussie charm. www.btstours.com.au
* Pacific Blue, the international airline of Virgin Blue, flies direct from Auckland to Cairns with one-way fares from $299. You can hire your personal in-flight entertainment system, the digEplayer, for just $20. If you fancy extra leg-room, book blue zone seating for an extra $45. Check out www.flypacificblue.com