I love to target Great Lakes post-spawn walleye when they start feeding in deep water. Especially when you can find them in 20-30′ depths and close to the bottom. That’s an easy time to target them fishing jigs/plastic grubs vertically.
These big Walleye can be concentrated in these areas early in the year but as the water warms up they will disperse in the main Great Lakes and often cruise open-water suspended looking to feed on large schools of baitfish, smelt and alewife. That’s when it’s best to troll for them.