Where do you find carp on the Great Lakes? You'll have to discover exact spots on your own. For some reason we had plenty of company this year in one of our carp'n locations. You'll find that after you catch a number of fish they will vacate the area, so more people equates to less opportunity per person. To find the fish look for shallow rocky areas that are home to a good population of crayfish. Common carp have crushers in their throats, so hard foods like crayfish are not a problem for them to eat.
Look for a stable weather pattern to get them in a feeding mood. Cold fronts and high winds really mess things up. You'll find them cruising the drop off in search of pockets of warm water. They are hard to catch in this state. A breeze or a light wind blowing into shore will push warm surface water into the shallows. A good amount of daytime sun will heat things up and provide the visibility needed to get your fly in front of the fish. The best fishing seems to come when it is miserably hot and sunny during the summer months. Dead calm conditions can test your nerves and send the fish packing when you try to drop your fly in their vicinity. You may find carp lazing or rafting around just under the surface. I suspect they are soaking up the sun. It's rare to get these fish to take a fly. Fish that are moving around slowly near the bottom in shallow water will offer you a good opportunity. If you see one head down and tail up, like it's inspecting a crayfish den, get your fly in front of it. This will be your best chance for a hook up.
An 8 weight rod with a weight forward floating line will work good. Something that loads up quick for casts of 20 to 60 feet. Big Great Lakes carp will definitely test the strength of your eight weight rod with their large fins and bulky body. The farthest I had them run is about 150 yards. Make sure you have enough line and backing to handle that distance or more. Even the small ones can take you into the backing. An abrasion resistant leader of about 10ft is a good staring point with tippets of 8-14lb test. Start heavy until you get a feel for what the fish can do. You'll also lose less flies to the rocks. We found fluorocarbon sparkles and spooks the fish so use tough monofilament instead. For flies use something that represents a crayfish. The pattern does not have to be exact. Something weighted to get to the bottom and about one and a half to three inches long.
Carp will chase down your fly when in the mood or refuse everything you throw at them. They are challenging, exciting , and the experience will be memorable. Lastly, watch your knuckles when they're headed for the deep.