It's Lake Mac's version of Willy Wonka's golden ticket: a $25,000 flathead lurking in the lake's depths, just waiting to be caught.
The piscatorial prize will be one of four tagged fish each worth $25,000 if hauled in and released during this year's Let's Fish Lake Mac event weekend, held 23-24 November.
One healthy tagged specimen from each of the competition's four target species – flathead, bream, tailor and whiting – will be released into the lake shortly before the event begins, with participants challenged to catch one and claim its $25,000 bounty.
Organiser Michael Guest said fishing tackle prize packs worth more than $34,000 were on offer as usual this year, but the tagged fish would add even more incentive to sign up and wet a line.
"We've seen how this kind of fish lottery has helped attract anglers to competitions in other parts of Australia, but this is the first time it has been offered locally," he said.
"It's a really fun way to encourage people to get involved, and there's a substantial reward on offer for anyone lucky enough to hook one of the four tagged fish."
Prizes will be on offer across junior and open categories for the largest specimen of each of the four target species caught during the weekend, along with 'mystery length' prizes and other prize packs on offer for simply entering.
Fish are photographed on a measuring mat supplied to all participants, before being released back into the lake.
Lake Macquarie City Council Coordinator Cultural Engagement, Marketing and Tourism Marsha Rodrom said local businesses were set to reel in the benefits of the event weekend.
"Past Let's Fish weekends have seen hundreds of fishing fans descend on the lake and our beaches in search of the target species," she said.
"Many are from outside the area, and we consistently see a significant boost in demand for accommodation and from other hospitality venues around the lake as a result."
"This event showcases the spectacular lake at our city's heart and encourages people to get outdoors and enjoy one of Australia's most popular pastimes.
Entry to this year's contest is $30.
Go to letsfishlakemac.com.au