Australia is one of the best known diving location in the world and is undoubtedly unique.  The continent is situated between the tropics and more temperate climbs and between the Pacific, Indian and Southern Oceans which gives rise to a massive diversity of sea life. 

Australia's diving areas are vast.  Although the Great Barrier Reef gets most of the press, better by far is the Coral Sea, whose outlying atolls and pinnacles such as Marion Reef offer some of the best diving in the world.

Cyclone season is January through March; April, May, and June see heavy trade winds.  Northern Queensland (Great Barrier Reef) could be worth avoiding during the early part of the year.

The best way to dive Australia is on a liveaboard from July to November. Best visibility at Osprey, in the northern Coral Sea, is between June and September. The other hot spots for Australian diving is on the remote west coast, and it's famous for one reason: whale sharks congregate at Ningaloo Reef during March and April.

Then there's New Zealand where you can dive a live volcano, fresh water caverns and see the black coral of Milford Sound.

In Australia, you must have a Recreational scuba diving medical to Australian Standard 4005.1 2000 (AS4005.1 2000).  The South Pacific Underwater Medicine Society lists doctors who have completed a Diving Medical Course and will be able to perform these Medicals. Medicals incur a fee which you pay directly to the doctor.