The charity Birdman Rally held at Melbourne's Yarra River involved participants flying homemade gliders without mechanical assistance.
The contestants jumped off a four-metre (13.1-feet) high platform above the river, staying in the air for as long as possible before crashing into the water.
Several of the 12 competitors turned up in colourful and bizarre costumes, including a man flying a bird made from balloons, another dressed as a shooting star and a woman holding a giant paper mache towel bowl.
"I seem to be the one to beat on the longest-distance flying aspect, I am a pilot, but it's not about that, I just love building a plane that you try to fly -- it's a bit of a childhood dream," Paul said, Melbourne's Herald Sun reported.
Paul, who reportedly reached 17 metres before his inevitable crash into the river, had also raised more than Aus$12,000 (US$9,075) in honour of his brother Lucas, who has multiple sclerosis, the newspaper added.