Also, think about the wind. In my opinion, there's nothing worse than a bad bouy throw. I can't stand worrying about the buoy getting caught up in the motor/trolling motor constantly, and you need to be able to see the buoy at all times to use as a reference point. If I see a good spot on down scan, I mark it on gps, then head upwind toward it. When I see it appear on screen, I wait until after I've run all the way over it, then throw a buoy out directly behind the boat. This puts you constantly nosing toward the buoy to stay on the pile while never going past it.

I have a pair of bouys that I purchased from Bass Pro that are in the shape of an H. They stay until it gets 25+ on the wind, but then I'm headed off the lake anyway.