The Big One Driving and Diving Australia's Great Barrier Reef Three words: Great Barrier Reef. Even if you've never dived, it's the one scuba-centric place in the world you're apt to know about. And with good reason: The reef is so big that it is the only living underwater collective viewable from outer space. With something that large, a single dive site can never be more than an appetizer. Fortunately, there's an easy way to see more: Don't just dive it - drive it. Start in Cairns, which, though it's in the northern part of Queensland, is in the lower latitude of Australia, a concept that takes most Northern Hemisphere residents a few minutes to get their heads around. From here, you can take a fast boat out to Michaelmas Cay, where Pacific corals and giant clams are waiting to welcome you to some of the most colorful diving of your life. From there, it's a short hop to Hastings Reef on the GBR proper, where turtles, dolphins and migrating minke whales are all apt to show up for cameos. If you have the time for a brief live-aboard run, Cairns is the jumping-off place for trips to the Cod Hole with its world-famous potato cod and the wonderlands known as the Ribbon Reefs, which include such renowned sites as Steve's Bommie and Pixie Pinnacle. Back into the car on the Great Pacific Highway, navigate south to Townsville, long known as the departure point for dive boats for the heart of the Great Barrier Reef. But the dive site Townsville is best-known for is not a reef at all, but a wreck - a wreck that many Australians consider their country's best dive. It's the SS Yongala, lost during the great hurricane of 1911, but undiscovered until 1958. Lying entirely within the World Heritage-listed Great Barrier Reef Marine Park, the Yongala is remarkably pristine and known for the sheer density and massive size of its inhabitants. You'll find sea snakes the size of your calves, huge Napoleon wrasse, jacks that look as if they're on steroids and sea turtles large enough to have their own gravitational fields. Don't miss a night dive on the wreck when the rays "pancake" on each other in stacks of five to 10. It's one of the most unique encounters in the marine world, but just one of dozens on the Yongala. Continuing south, you come to Gladstone - the starting point (via your choice of boat or helicopter) for Heron Island. Heron is the "it" place for Great Barrier Reef diving because sites that you would gladly endure an hours-long boat ride for are typically five minutes from the dock. Just two minutes from the harbor, for instance, you come to Heron Island Bommie, one of the most photographed underwater cleaning stations in Australia - a virtual riot of colorful corals populated by jacks, barracudas, morays and a host of tropical species, and visited regularly by sharks, eagle rays and mantas. Or venture out to Tenements 1, world famous for a huge blue-tipped anemone that is home to a crowd of some three dozen clownfish. And the island is crawling with nudibranchs for the macro crowd. For surface days and non-diving companions, Queensland's Pacific Coast offers dashes inland to both the Out- back and the rainforest, food and wine tours, four-wheel-drive adventures and waterfalls galore. Think "California" - only wilder, much less populated and more adventurous - and you'll have a hint of what waits here. And no matter where you go on this coast, you know that the reef is out there, waiting. Quick Guide: Must Do: Need For Speed - If you find yourself near Surfers Paradise in mid-to-late October, when the event takes place, watch the stars of Indy car racing in action on their one Australian tour stop, the Gold Coast Indy 300. Must Dive: Hastings Reef, Cod Hole, SS Yongala, Heron Bommie, Tenements 1