Australia II, bearing sail number KA6, represented the Royal Perth Yacht Club of Australia in its September 1983 challenge for the America's Cup. The defender, the New York Yacht Club, had held the cup since 1851, dominating challengers and sustaining the longest winning streak in sport.
The Australia II, skippered by John Bertrand, faced Dennis Conner sailing the 12-metre Liberty in the ocean off Newport, Rhode Island. Australia II came from behind to prevail 4 races to 3. The victory on September 26, 1983 was a landmark event for the nation of Australia, not to mention the Royal Perth Yacht Club, and it eventually earned Australia II the ABC's Wide World of Sports Athlete of the Year for 1983.
The Boxing Kangaroo was the official mascot of the Australia II effort. The win was received with much enthusiasm in Australia, with the Men at Work song Down Under becoming the official anthem for the crew.
In the film Wind, Australia II is portrayed as Boomerang.
In the mid-1980s,www.hqreplicas.com Australia II was sent to the Australian National Maritime Museum in Sydney, Australia for display. For the 150th anniversary of the America's Cup, the boat was removed from the museum and shipped to the Isle of Wight, sailing with the original crew for several days of commemorative regattas. The boat has since been returned to Fremantle, Western Australia where it is on permanent display in the Western Australian Maritime Museum.