Big Blue Planet knows about the following countries in this region:

The east coast of Australia runs from the Cape York Peninsula in the north, all the way down to Sidney. The Great Barrier Reef rightly dominates the diving on offer on the east coast and is usually accessed via Cairns and best achieved with a Liveaboard. Outside of this area you still have other great diving such as Jew Shoal and Jervis Bay.
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The west coast of Australia is a bit of an undiscovered jewel still with it's pioneering feel. Diving areas include the purposely sunk wrecks of the Lena in Bunbury and the HMAS Swan in Dunsborough, or travel further north to swim with Dolphins in Monkey Mia, or further north still to swim with Whale Sharks at Ningaloo Reef.
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