Giving him tips on how to conquer the world record attempt is fellow Tassie pilot Oliver O'Halloran who currently holds the record after a solo flight in 2017 aged 17.

"I met Oliver at Devonport airport the morning before he departed on his flight and he inspired me to start flying," Bob said.

"I'm a few months younger than he was when he completed his solo trip, so I'll actually be breaking his record but that hasn't stopped him mentoring me on my journey.

"His biggest tips have been to not push myself too far or too hard each day, to be relaxed and most of all to enjoy it."

After a few months delay due to bad weather, Bob was keen to start his adventure - leaving Devonport airport on Monday and arriving at the Illawarra Regional Airport on Tuesday morning.

Wollongong is the fourth of 40 stops on his 15,000km journey which - weather permitting - will see him land back where he started on May 7.

His flight, which is called 'Surviving Turbulence', is not just about breaking records - he's also partnered up with Beyond Blue to raise awareness about youth suicide.

"In late 2017 I almost lost two friends to suicide," Bob said. "So I'm passionate about youth suicide prevention and the first step is to get people talking about it, to stop the stigma that surrounds it."

He thanked the Devonport Aero Club; the owner of the Cesna 172 he's flying, Allan Brooker and, of course, his mum and dad.

"You don't expect your child to tell you they want to become the youngest person to circumnavigate Australia solo, so they were sceptical at first," he said, "but they've been really supportive."

The Year 11 student's flight was made possible by a $15,000 donation from Westpac, plus other corporate sponsors and a crowdfunding campaign.

And on his journey he'll keep in mind his favourite quote.

"It's a quote I live by - 'The difference between the impossible and the possible is a matter of determination','' Bob said. "If you want to do something, go for it. If someone can do it, why can't it be you?"