The Great Barrier Reef is one of the world's most celebrated and evocative destinations - all crystal clear waters, white sand and rainbow-hued marine life.
The world's largest coral reef, it stretches for more than 2 000km and is home to 500 species of tropical fish and hundreds of types of starfish, sea urchins, molluscs, sponges and crustaceans. Even turtles, whales, dolphins and manatees visit in season.
The Great Barrier Reef is the most protected coral reef system on earth. Snorkelling and diving are the main reasons to visit the reef, but even if you hate water, it is still worth visiting.
Of the 900 islands, 100 are habitable and landlubbers can walk in unspolit rainforest among the 2 000 plant species, or just enjoy superb hotels and spas. But with such a large destination, what is the best way to tackle it? Here are my tips:
Even if you only have a day to spare, it is still worth making a visit to the reef, with Cairns, Townsville and Airlie Beach all good jumping-off points for a day trip.
From Cairns in the far north of Queensland, a 45-minute boat ride will take you to Green Island. This is one of the smallest islands on the reef and looks like a child's drawing of a deserted island - lush vegetation, fringed with white sand and surrounded by azure seas. Snorkelling here is superb.
Big Cat Green Island Reef Cruises (www.bigcatcruises. com.au), found at Reef Fleet Terminal on Spence Street, does day trips. Ticket costs include snorkelling gear.
A little further south, a 20-minute catamaran ride from Townsville will take you to Magnetic Island. Visibility is not quite so good for snorkellers, but it is close to Yongala, voted one of the world's top five wreck dive sites. It also has a reputation for good dive schools for beginners.
From Shute Bay near Airlie Beach on Queensland's central coast, a ferry will take you to Daydream Island, 3.2km away. It is very child-friendly and has a huge outdoor aquarium for nervous swimmers and children. Alternatively, take a one-day sailing trip, see a number of different islands and snorkel from the boat itself. Cruise Whitsundays (www.cruisewhitsundays.com) offers a variety of trips.
Two-day trips
If you have a couple of days to spare, I recommend splashing out on a really luxurious experience. The two most exclusive resorts on the reef are on Lizard and Bedarra islands. The individual wooden villas blend effortlessly with the environment of the rain forest, are beautifully equipped and provide exemplary food and service.
Lizard Island is the most northerly of the resort islands. Most of its vast hinterland is national park and there is wonderful hiking through lush forests rich in wildlife. It also boasts some of the best diving on the reef and has fantastic and easily-accessible snorkelling.
The deep-sea fishing here is also highly rated. With 24 beaches to choose from, it feels as though you have the place to yourself.
Bedarra Island is equally luxurious and, with even fewer guests, feels still more exclusive. However, it is a little farther from the reef itself, so snorkelling and diving are a longer boat trip away. Here, too, you get a real sense of how the other half lives, with top-class service and fantastic food and wines all included in the price.
Both resorts are owned by Voyages (www.voyages.com.au). Qantas, Jetstar and Virgin Blue fly to Cairns from Sydney. From Cairns to Lizard is a 60-minute flight with Hinterland Air. From Cairns to Bedarra is slightly more complicated - a 40-minute Hinterland flight to neighbouring Dunk Island, followed by 40 minutes on a boat.
Longer stays
A full week gives you far more choice: travel farther away to a more remote island; choose a sailing trip and visit different islands; or make your money go further and opt for a slightly cheaper, cheerful option, with plenty of activities on offer.
Best for sailing
The group of 74 islands known as the Whitsundays lies opposite the town of Airlie Beach. Easily accessible, they provide the best year-round sailing opportunities.
Each island has its own characteristics, but all provide good snorkelling and diving opportunities.
Expensive Hayman is home to a five-star resort with the largest swimming pool in the southern hemisphere; Hamilton has its own airport, is the biggest inhabited island in the group and the most commercialised; quieter, more affordable South Molle is a national park; while Hook is for the more adventurous, as you need to camp.
Hook has the highest mountain in the group and some good examples of Aboriginal cave paintings. Another big draw is Whitehaven beach, on Whitsunday Island. With nearly 6.5km of pure white silica sand, it is consistently voted one of the top three beaches in the world, and is easily visited on a day-long sailing trip.
If you want to eschew land in favour of life on board a sailing boat there are many options: Whitsunday Tourism (www.whitsundaytourism.com.au) offers three-day sails or, if you want to skipper yourself, then you can go bareboating. Prices vary, but most boats sleep between six and 10. Sunsail (www.sunsail.co.uk) is a consistently reliable sailing holiday company.
Best for snorkelling
Heron Island is one of the few true coral cay islands - actually made of coral and situated right on the reef (www.heronisland.com). This is a huge advantage as there is no messing about with boat trips - you can snorkel directly from the beach.
And what snorkelling it is. The range of fish and coral is divine and I saw turtles, manta rays, even a small shark. It also has one of the best dive sites on the reef and, with its own research centre, is both a bird sanctuary and a turtle nesting ground.
Consequently it tends to attract nature lovers, and you can join guided reef walks at low tide, island ecology walks, birdlife walks, even go stargazing. No buildings have been built above the tree line, and no daytrippers are allowed.
Getting there is quite an effort, so you need a few days to make it worthwhile. Flying to Gladstone from Sydney requires changing planes in Brisbane and, depending on transfer time, can take from four to eight hours. Next you have the choice between a two-hour boat trip or a half-hour helicopter ride.
Best for camping
Lady Musgrave Island (www.smartservice.qld.gov.au) is a tiny coral cay island surrounded by a huge expanse of reef. It is beautiful and abounds in wildlife both on and off shore. Between November and March you can see green turtles laying and hatching, while between August and October you might get to see migrating humpback whales. It provides excellent snorkelling and diving. You will need to take a tent and all your own supplies, including water.
Bundaberg is a five-hour drive from Brisbane. The ferry to Lady Musgrave goes from Bundaberg Port Marina (www.lmcruises.com.au).
Best for activities
Dunk Island (www.voyages.com.au/dunkisland) is family-friendy, with endless options for keeping busy, from kayaking and waterskiing, to windsurfing and golf. The resort is large, friendly and recently refurbished.
From Cairns, you take a 40-minute Hinterland flight.