Locating Them
This is tough this time of the year. But I agree with them being shallow and soaking up the rays on the North or Northwest shorelines. Find some rocks if possible. They seem to warm the water the fastest.
I like using a 1/32 oz. marabou jig suspended under a slip bobber. With a little chop on the water and fishing in the noted locations, you should find some. When it's calm, you can visually look for them. You'll see a school of fins! Use your polaroid glasses too.
"A voyage in search of knowledge need never abandon the spirit of adventure."