Gentlemen of the BassinUSA Pro Staff: I would like to get a sizable comment from as many of you as possible on this subject.
For years my electronic engineering friends have been needling me about bass anglers' reliance on "Fish I.D. Fabrications" and a general lack of true lake bottom representation in ANY LCD displays. They have mentioned the default credibility as being "less than advertised" and that the display itself is a good number of feet behind you, by the time you read it.
Now, I realize that some of you are sponsored by Depth Finder Mfgrs. So, if you'd rather not go on line on this subject, I understand. Those of you who want to talk up, have at it. Thanks, JoeM

True and accurate representation of the bottom is a relative term. The unit is taking echo data from a circle and trying to display it in two dimensions in a straight line. All it is, is a representation of the averages in the return readings. So,no its not perfect but it is easier to read and interpret than a flasher. It also leaves its images on the screen for a period of time so that the angler can evaluate what he see's. Think of a flasher and how little that shows, yet it revolutionized sportfishing. So if I'm going to use it and make it the functioning tool that it can be for me,I want to eliminate as much automatic interpretations as I can. I turn off all alarms and automatic modes. ( fish ID, shallow water alarms etc.) I split my screen and get the general picture on one side and the Zoom or bottom lock on the other. That allows me to compare the two. I turn my sensitivity to where the screen is just one click to the clear side of showing plankton. Lastly I turn up my grayline so I can get an idea of the bottom makeup. This is where I start. If I want to find the thermocline, I crank up the sensitvity until it shows me where the plankton ends. What I call plankton on the lcd screen is that general cloudiness, those marks they call interference or something else that obscures the screen. With the sensitivity cranked up, in deep water that band will end and below it is clear screen. I believe that I'm picking up the change in density of the water. I've tried this with another fellow in the boat with a thermometer and it works. If I'm lookin for something different in a weed bed I turn down the sensitivity a bit, this give me less weed reading on the screen, but I can still determine the bottom and any hard objects like logs or rocks. When I got my first depth finder I went to places in Long Island Sound, where from charts or personal experience I knew what the bottom make up was and studied what sand, gravel and rocky bottoms looked like on both flashers and LCD units. I was able to jump along the learning curve faster by doing that. They are tools and they require practice if they are going to be more to you than a drop off finder. Good luck.
Frank

Frank- A very detailed excellent answer. Most of these things I've done with mine and it has worked for me. The only thing that I try not to use ever is Fish I.D. It might make some guys comfortable to think there are bass around if they are on the screen, but that's not for me. Manual is the way to go as far as I'm concerned. Thanks for a great post. JoeM