The 71-year-old has designed two flags, one reminiscent of the current flag and the other more akin to the design favoured by Prime Minister John Key.
Mr Campbell said it was embarrassing when Americans mistook New Zealand's flag for Australia's at the successful 1995 America's Cup challenge by the Sir Peter Blake-led team off San Diego.
He remembers Americans saying "what are you Aussies doing here" when they spotted the flag.
The memory spurred him to fly an alternative flag in Shed 10 on Auckland's waterfront during the successful challenge by Oracle for the America's Cup in 2013.
Changing the flag did not mean New Zealanders would forget the past and how they fought under the Union Jack and Southern Cross flag.
"It is about getting our own identity. Look at how many changes there have been in New Zealand. It's time we supported our champion athletes with a new flag."
Asked if it was the wrong time to change the flag during World War I commemorations, he said "It is and it isn't. You will always get the hard core who want to keep the flag."
He believed that one of his designs would appeal more to the traditionalists, particularly if his little Union Jack component was instead blended into the background fabric of the flag.
Mr Campbell looked forward to seeing New Zealand's champion athletes draping a contemporary flag around their shoulders rather than a flag that represented a different era in the country's history.
He will probably submit his black flag for the design competition, which will see the Flag Consideration Panel select three or four flags for a national referendum. The vote was expected to take place at the end of this year. A second referendum in April 2016 would see New Zealanders vote whether they wanted to change to the winning alternative design or keep the current flag.