The Bluewater Anglers' 40th annual salmon derby began at 12:01am Friday, and runs through until Sunday, May 8.
Director Brad Armstrong says it's both a boat and shoreline event.
The boundaries range from Fawn Island to Grand Bend, and up the US side to Lexington.
"Early spring fishing, when the water is really cold, the real trick is to slow stuff down," says Armstrong.
"People start slowing down with their trawling. The guys off the shore tend to do really well because they're stationary fishing. As the water warms up, the fish get more active as we get more fish into the area."
Over $40,000 in cash and prizes are up for grabs.
Last year, over 1,000 anglers entered the derby.
Tim Nolan of Camlachie caught the heaviest salmon, weighing in at 17.44 lbs. Tricia Geerts caught the heaviest overall fish, a 19.8 lbs lake trout.
You can hear daily salmon derby reports throughout the event on 103.9 FM, 1070 AM CHOK.