Well beyond looking for the structure that you can see...there are a couple ways. First off look at the shoreline. More times than not it will mimic the bottom right in front of it. If its rocky, you can bet the water in front of you is rocky. If its sandy, well you get the point. You want to fish structure, so, look for a point. If you se a point of land sticking into the water, you can bet that point continues underwater. Fish the bottom, bouncing your bait across the bottom and PAYING ATTENTION will find you holes and structure. I haven't tried them yet...but for fishing the shoreline they make wireless fishfinders that clip to your rod or that you wear like a watch. maybe you could try that if you dont have any lucky reading the area you're fishing.