Yeah, train them early. My waters, although dammed, I can still read the water much like reading the riffles, holes and runs of a trout stream. None of the catmen in my area use sonar, yet catch 40 fish at a time.
I gather that the difference is your waters are far more vast than ours, akin to fishing the Gulf and opposed to fishing the bay. From what I hear you fellas saying: the smaller the waters the less you need sonar.