Structure allows baitfish to hide and does many other things. Where baitfish hide is the best place for recreational fish, large recreational fish, to find baitfish. So it is import to understand structure.

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Underwater structure maps:

Finding structure is easier if you have a topo map. This is particularly true if you are looking for deep structure such as for hot weather bass. A good topo will show structure including points, old roadbeds and structures, submerged forest, original channels and creeks, drop-offs and others as well.