Use a transducer mounted on the bottom of your trolling motor on the front of the boat. Then when you mark them you know you are close. You can use a basic graph, doesn't have to be a high dollar one for this purpose. That's how I used to catch them at High Rock Lake years ago. As others said, if you can find a spring or warm water discharge of some kind, it can make quick work. I have found them so thick before that it literally took two of us to pull in an 8 ft net. Wish I could find a good gizzard shad hole close to Seneca. Have heard Saluda lake may have some gizzards. Anyone got any info willing to share. I got two teenage boys just raring to throw some nets...