The most famous extreme sport of them all. Attach yourself to a giant rubber band and throw yourself off somewhere inadvisably high. AJ Hackett is the original bungy company and still the best in the world. The tropical Cairns setting just adds to the mind-blowing rush.
The traditional way to see the Whitsunday Islands is over three days on a sailing boat, but if you're short on time (or patience) you can whizz around them on a half-metal, half-inflatable craft. It's not actually a raft, more of a very light boat with a very large engine. Imagine the offspring of a military landing craft and a banana... You miss out on lots of peace and tranquillity, but it does get you to the best spots quickly, and is great fun to snorkel off.
The Tully is Australia's best white-water rafting river. It's a full day activity, but you don't need to stay in Mission Beach if you don't want to: it's very easy to book from Cairns and the company will provide transport both ways. But Mission Beach is small, very chilled and well worth a couple of nights.
Surfers Paradise is as good a place as any to organise your zorbing. Get into a giant hamster ball and roll down a hill. Simple really. We can't believe it took so long for someone to come up with the idea.
You can't say you've been to the east coast of Australia if you haven't at least had a go at surfing. There plenty of great spots between Sydney and Brisbane, but Byron Bay is best for beginners. There are plenty of surf schools about, so the prices are pretty reasonable. Don't be shy, it's not as hard as it looks and you'll probably be standing up within two or three hours.
There are lots of places to skydive in Australia and nearly all of them offer something spectacular to look at while you're plummeting earthwards. The views at Byron are among the best though, which is why we recommend doing it here.
You can jet boat in Sydney or up in Cairns; it just depends where you'd rather turn into a stomach churning blur... The basic premise is that you get into a very high-powered boat and hoon around the place with a driver who lives to scare the hell out of backpackers.
The Great Barrier Reef is enormous and stretches most of the way down the east coast. The Ningaloo Reef is a bit smaller, a lot quieter and off the coast of Western Australia. Both are marine paradises, excellent places to learn to dive and full of opportunities for experienced divers.
Organise your trip from Hervey Bay or Rainbow Beach. The standard self-drive trip is three days, two nights and you'll generally be in a vehicle with seven other backpackers. Just hope they're nice... Fraser Island is probably the highlight of most people's east coast trip. Camp on the campsites if you want facilities, camp on the beach if you want to stay up late and enjoy yourself. Whatever you do, don't feed the bloody dingoes, mate.
Nothing like taking a camel safari along a seemingly endless, pristine beach as the sun sets over the Indian Ocean. Okay, it's only going to get the adrenaline going if you've a fear of camels, but it's a nice way to end the day...