Ian Kiernan lived three very different lives.
He was an avid sailor, a prolific Sydney property owner, and one of the world's greatest environmentalists.
But throughout it all - he was always drawn to and loved the ocean.
"He was mesmerised by its power and beauty," the Clean Up Australia founder's daughter Pip Kiernan told his state memorial service in Sydney on Friday.
Ian Kiernan the founder of Clean Up Australia onboard the new Solar Sailor. Source: Supplied by Danyal Syed
"My dad showed us all that just like the oceans he loved, human potential is limitless."
Hundreds gathered at the Sydney Opera House to pay tribute to Mr Kiernan, who died in October after being diagnosed with cancer in July. He was 78.
His daughters, Pip and Sally, said their father was determined to protect the ocean after being dismayed by the pollution he saw as he sailed the world.
Daughters Sally Kiernan (left) and Pip Kiernan speak during the State Memorial service for Clean Up Australia founder Ian Kiernan at the Sydney Opera House. Source: AAP
Sally described him as a "cheeky rascal" and "loveable rogue" who always aimed high.
He turned his love for the ocean into a movement when he founded Clean up Sydney Harbour 30 years ago, before it became Clean Up Australia a year later. It went global in 1993.
The organisation's co-founder Kim McKay said her friend and 1994 Australian of the Year had left a long-lasting legacy both in Australia and around the world.
"He was a self-described ordinary Australian, but of course, he was anything but ordinary," Ms McKay said at the service.
"He proved an individual can make a difference."
The service was attended by former prime minister Paul Keating, NSW Premier Gladys Berejiklian and Australian rock singer Jimmy Barnes who performed a rendition of Working Class Man.
Jimmy Barnes performs Working Class Man during the State Memorial service for Clean Up Australia founder Ian Kiernan at the Sydney Opera House. Source: AAP
He was remembered by Ms Berejiklian as "one of a kind".
"(He was) a patriot and environmentalist and a true humanitarian who truly left the world a better place," she said.
Blanche d'Alpuget, the wife of former Australian prime minister Bob Hawke, described Mr Kiernan as "the most gorgeous man" and "wonderful Australian".
"His legacy for the world is something that will go on for decades and decades," she told reporters.
Mr Kiernan graduated from Sydney Technical College as a builder and later specialised in historic restorations.
Those gathered at Friday's service were told by MC Mike Munro that in the early '70s Mr Kiernan was one of the biggest property owners in Sydney owning "most of the suburb of Pyrmont".
Mr Kiernan received several honours including a Medal of the Order of Australia in 1991 and in 1995 he was appointed an Officer of the Order of Australia.
He is survived by his wife Judy, daughters Sally and Pip, and son Jack. The family has requested people donate to Clean Up Australia in lieu of flowers.
