Only slightly farther north of Heron lies the Whitsunday Archipelago, a string of 74 islands in the Cumberland group encrusted with sand and coral. For an independent reef experience, hire a bareboat at a fraction of Caribbean prices. A skipper is free for the first day, and $100 a day thereafter until you're confident enough to strike out alone. Of the islands, 66 are entirely national park (the only developed ones to avoid are Hamilton, Daydream, and Hayman). There are hundreds of protected anchorages to choose from, most with solitary beaches, fine snorkeling, and hiking. Fishing is permitted in designated areas.
A dozen or so boat-hire companies operate out of Airlie Beach and Shute Harbour, just beyond Proserpine, but a good start is Rent-A-Yacht (in the U.S.: 800-788-6685). Rates start at $200 a day, with a five-night minimum. Catamarans and motor cruisers are also available (the latter, an obvious choice for more lubberly skippers, start at $250 a day).
If that's all too pricey, hop a ferry to one of the 20 or so campgrounds on the islands. For $40, take the regular service out to large, lush Whitsunday Island and camp at the southern end of blindingly pure Whitehaven beach, one of Australia's finest; alternatively, the privately run campground on Hook Island has excellent hiking and snorkeling. (You can book all of these services via the travel agency Destination Whitsundays, 79-466-848.)
Off the Queensland coast between Brisbane and Heron, Fraser may be the world's largest sand island, but it's far from barren desert. Every corner overflows with greenery200-foot satinay trees, banksias, even tropical rainforestall growing on nutrients gathered in the top three or so feet of sand. The weather is steamy at this time of year, but there's water everywhere. At the ends of hiking trails you'll find sand-bottomed lakes for swimming (in some, like Lake McKenzie, the water is Caribbean blue; others are the color of tea). You can float on your belly down clear Eli Creek through the rainforest, or climb the giant dunes that drift across the island like mini-Saharasonly to bolt back down and crash straight into another lake. And Fraser's entire eastern coast is taken up by 75 Mile Beach, upon whose hard-packed shores four-wheel-drive vehicles race up and down at low tide.
On the west coast, the wilderness lodge Kingfisher Bay (doubles, $185; 71-203-333) is a study in eco-chic. Almost hidden by the surrounding bush, its glass-walled lobby is a postmodern cathedral. Kingfisher makes a fine base for the first few days, but to get the most out of Fraser, head "out bush" with your own tent and four-wheel-drive vehicle. It's easiest to rent a car in Brisbane and drive the three and a half hours to meet the barge from River Heads, just south of Hervey Bay; the fare is about $50, and reservations must be made with Kingfisher Bay. A four-wheel-drive permit is also required: It costs about $12 from the general store at River Heads. Free-range camping is permitted up and down the east coast of Fraser, but Dundubara campsite, with showers and barbecue grills, is just back from the beach in the northeast; it's the shadiest spot to pitch a tent. (Camping permits cost $6-$10 a night; obtain them on the island at the Eurong information center, 71-27-9128.) Pick up supplies and beer from the tiny island community at Happy Valley, fish straight off the beach, and prestoyou're an honorary local.