A couple of years ago, I caught my biggest fish of the year fishing with the DIRTY DOG in Grand Haven at this time of the year.
This fish came on a Stingray size Freakin Veggies.
Like Jon said, fish in the mud. This is the plume of dirty water that comes out of the Grand River. You will see the temp difference between the clean water and muddy water. You want to stay in the warmer water.
I would run a North/South troll and keep my baits within the bottom 10'. I would run a couple of boards off each side of the boat, and 2 riggers, with at least 50' leads behind the ball. I would also have sliders on so I could have an extra 2 lines in the water.
I would have on a spread of Stingray size spoons, in the flavor of: Freakin Veggies, Craigs X-Mas, Orange Killer, Mixed Veggies, Killer Tangerine, and the Natural Born Killer. In the low light hours of the predawn, I would have Stingery size Nitros in Twister, Area51, ET, Nitro citrus, and Napalm.