Later claims of Dutch Design for details). Claims that Peter van Oossanen was the designer of the Australia II keel rather than Ben have been strongly rejected by John Bertrand and by John Longley, an important member of the Australia II team using documentary evidence. The 1983 America's Cup saw Lexcen's Australia II, with John Bertrand at the helm, take on the NYYC skipper Dennis Conner and the defender yacht, Liberty. The Australians were sure they had a fast boat. Australia II had dominated the challenger eliminations just as Liberty had dominated the closer defender trials, honing her tuning and performance. But mechanical failures on Australia II and skillful sailing by the defenders caused Australia II to fall behind, losing the first two races. Australia II stormed back to take three of the next four. Dennis Conner had creatively registered three different configurations (sail area, spar length and ballast) for Liberty and he successfully called for lay days to choose advantageous weather to suit his most competitive versions of the boat. This was the first time in history that the series depended on the result of the last race, and the pressure of defending the Cup was now firmly on Liberty. In the deciding race on 26 September, Conner prepared Liberty in her very competitive light weather configuration with big sail area and low weight. Australia II won the start and held an early lead but was overtaken by Liberty which built up a substantial margin. At the start of the penultimate leg (a square run) the breeze was very light and Liberty was vulnerable. Liberty chose a starboard tack leg and declined to cover Australia II which allowed them to run deeper and faster assisted by breeze and windshifts allowing Australia II to overtake the Americans by the leeward mark. Liberty then engaged Australia II in a spectacular tacking duel with nearly 50 tacks and a number of faked "dummy" tacks trying to break the Australians' cover. Australia II held on until both boats reached the starboard layline in amongst the spectator fleet and tacked several boat lengths ahead of Liberty and sailed to the finish to take the race. Australia II became the first challenger to wrest the Cup from the United States since its inception in 1870. Lexcen was made a Member of the Order of Australia for his contributions to the winning design. Lexcen was commissioned