Mr Hart had always been interested in sharks, snorkelling with reef sharks as a child and cave-diving with great white sharks off Stewart Island in 2012.
"When you see them in their natural environment, they're such incredible creatures.
"It's movies like Jaws that created an irrational fear of sharks in this generation."
Poachers catching sharks, removing their fins and releasing them back into the ocean to die were killing off huge numbers, he said.
He had wanted to hitchhike down New Zealand for a number of years and with the incentive of fundraising for WWF, the idea became a reality.
He made the most of his last summer holiday between graduating university and starting his first job, to put together his hitchhiking campaign.
The debate of whether the shark suit helped or hindered his attempts at getting a free ride was the "million dollar question", he said.
"You have to be a certain type of person to pick up someone wearing a shark suit," he laughed.
"People get a laugh out of it. It's not often you see a guy in a shark suit hitchhiking around New Zealand."
So far so good, he said, although he had spent one night camping on the side of the motorway north of Auckland when the shark suit had not pulled through for him.
He was lucky enough to get a free trip across the Cook Straight thanks to Interislander.
He hoped to reach Christchurch by the weekend before flying back to Auckland and supporters can keep up to date with his trip on his Facebook page Andre's Great New Zealand Hitchhike!.