He was one of nine people who braved cool conditions to throw themselves off Holmes Wharf in an attempt to win the prizemoney in the Port FM-organised event.
Mr Walmsley spent about two days making his futuristic wings from cardboard, tubes and "lots of duct tape".
His aerodynamic creation evolved, rather than being planned and he was sure he had the winning combination.
He was proved right, winning $300 for the longest flight.
Mr Walmsley lost his grip on the wing, and felt he could have gone even further with the help of the head wind.
However, the overall prize, along with a new trophy, was awarded for a combination of three categories - longest flight, best costume and biggest splash.
That prize went to Campbell RussellThe trophy was in memory of Lachie McLean, the Oamaru teenager who died in a fire in 2007.
Mr McLean won the first two birdman events at the festival.
Port FM's Ryan Mountford said Mr McLean "gave anything a go", including the birdman contest.
The Oamaru Trust-Port FM carnival is organised to give Oamaru organisations and groups a chance to raise money.
It was not held in 2008, but yesterday more than 30 stalls were set up for the all-day carnival which was reminiscent of carnivals run at Friendly Bay in the harbour.
Organisations together usually raise about $9000 to $10,000 during the day.
Entertainment included a concert, the birdman contest, children's entertainment, helicopter rides. a rowing challenge and a display by North Otago Search and Rescue of sea rescues using a helicopter.
