You and a friend could join National Geographic wildlife research scientist Mike Heithaus in Australia. (See grand-prize trip itinerary for details.)

Learn secrets of marine life as you explore Australia's beaches with Heithaus, one the world's leading shark experts. Explore the vibrant streets of Sydney and the city's beaches, discover Queensland’s underwater world and ancient rain forest, learn about the Northern Territory’s ancient indigenous culture and art, and wander the nature reserves of Tasmania to see wallabies, wombats, and Tasmanian devils.

If you win, your vacation will take you and a guest to Sydney in New South Wales; Fraser Island, Cairns, and the Great Barrier Reef in Queensland; the outback of the Northern Territory; and the wilderness of Tasmania. Discover the immense beauty, natural wonders, and extreme conditions of this many-colored island continent.

Provided by Tourism Australia, the grand-prize trip will last 17 days and 15 nights. It must be taken between September 1 and December 31, 2006. (See grand-prize trip itinerary for details.)

This sweepstakes is open only to legal U.S. residents (excluding Florida and Puerto Rico residents) who are at least 18 years old at the time of entry. For specific details, check sweepstakes rules.