Trying for flathead catfish - How long to wait?

From what I've noticed...how long you should wait at a hole depends entirely upon who you ask. And justifiably so...every body of water is different, and every differing condition changes things. I fish a low water dam primarily, and theres been times I have sat there without a bite at a certain honeyhole for 6 - 8 hours...and then all of a sudden the action turns on like someone flipped a switch. Other times I have hit a fish right off the bat and the action doesnt cease for hours. And yet other times I just simply dont get a bite....and then other times the hits are seperated by a half hour to two hours apart. Confidence in your spot is key....as well as the type of spot you're fishing. Think about it like this...if you're cruising the river and jumping from spot to spot...you're probably dealing with territorial fish that spend most of their lives in one spot next to a log, ball of roots, muddy ledge, or rock pile. A prime example is this...I visited Bass Pro Shops in Springfield, Missouri a few years back, and there was a flathead sitting in a little nook right beside where you go down into the viewing aquarium where they feed the fish...I went back over a year later and looked in that nook...and there was the same flathead sitting in the same place...if that tells you anything. I have been back since...and didnt see the flathead...I asked one of the divers about it, and she said they had to get rid of it because it wasnt playing well with the other fish....it tended to sit still during the day and wouldnt eat the dry food they feed the rest of the fish...preferring instead to eat the other fish...at least the ones it could fit into its mouth. There is right now an 80 lb bluecat in there...but she said it is satisfied with the dry food now...but when it first got put into the aquarium....the very first nite...a record sized 4 lb crappie came up missing overnite when there was nobody there.
However...if you fish a low water dam...one that the fish cant pass over...they tend to concentrate and congregate in that area....laying low during the day...and spreading out to feed in nearby riffles at night. There are exceptions to these habits in my experience though. I fish a low water dam on the Neosho river that impedes the progress of migrating flatheads and blue cats. The fishing there is as good during the day as it is during the night for flats and for blues. The flats prowl back and forth along the low water dam and all you need to do is anchor...throw out your live bait...and wait. Something will be along sooner or later and at the very least liberate your bait for you...either that or get hooked. Notice I didnt say get caught...as thats not always the case as we all know. The old addage is true..."Thats why they call it fishing son...and not catching."