The Civil Aviation Safety Authority is the body responsible for all flying in Australia - from Thrusters & Gliders to Airbus A380, including pilotless drones.
CASA delegates some of it's authority to specific industry organisations, such as Recreational Aviation Australia, which looks after recreational fliers and their aircraft, like us.
AirServices Australia is responsible for the operation of Australia's airspace. They also produce the AIP - Aviation Information Publications - and all the navigational charts.
The ATSB is responsible for the investigation of accidents and incidents, especially those involving death or injury. It's one of the bodies you must report an accident or injury to. Check the Opreations manual for details.
The Australian Maritime Safety Authority is based in Canberra, and have the responsibility for coordinating all searches and rescue operations in Australia and Australian airspace and waters. They also hold the beacon register, which helps them in their primary task whenever an emergency locator beacon is activated. Each of our Jabirus is equipped with a registered Personal Locator Beacon.