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Choosing A Fish Finder For Catfishing

choosing a fish finder for catfishing


This article is part of an ongoing series called Blue Catfish 101.

Hopefully by now you have read enough here to know that if you are going to be catfishing for blue catfish the #1 tool in your catfishing boat is your fish finder. If you have not already read that article you need to go back and do so (see the #1 tool in the blue catfish anglers boat)

Having a reliable fish finder is of the utmost importance when catfishing for blue catfish. There are certainly times of the year when you can pattern blue catfish without a fish finder using natures “tattletales” or knowledge of the patterns of these fish but for much of the year having a fish finder is of key importance.

Buying marine electronics are like anything else related to technology. if you buy the latest and greatest model that just came on the market you are going to pay a premium price, and within a year or less the price is going to drop significantly. If you wait two or three years don’t even look at the price the same unit will be selling for because it will make you nauseous.

Fish finders have made some huge strides in the past few years. Color screens have been around for quite some time but the latest and greatest features like side imaging, down imaging and high definition displays are the biggest thing to hit the marine electronics (fish finder) world in the last ten years and this technology is an absolute game changer for catfish anglers.

In this article, I will walk you through some of the basic features to look for when choosing a fish finder and some of the key features to look for, and then in the next article in the series I will give you my top picks for fish finders.

First and foremost you need to understand what sonar is and the basics behind how sonar works how it works. A fish finder comes with a small part called a transducer that is mounted in the outside of the boat (or inside the boat against the hull) that sends sound waves out. Those sound waves shoot out in a cone shape from the transducer and when they hit something they bounce back up to the transducer. The transducer processes these signals and provides the depth of the water, bottom contour and also shows you anything else (fish, bait, cover etc.) that those sound waves hit in the water column.

This is obviously a pretty simplistic watered down explanation. If you want to become the Mr. Wizard of sonar and fish finders then do some research online, there are plenty of resources available like this overview on Wikipedia.

Before getting too deep into choosing a fish finder let’s take a look at some of the key difference between the latest technology in marine electronics.


Traditional 2D Sonar – This is the technology that has been prominent for the past ten years with a sonar view of what is below the boat in a 2D display, showing bottom contours, structure, fish and cover in a 2D view.

lowrance x-135


Side Imaging – Side imaging provides an ultra clear 3D image of sides of the boat showing a picture looking from the left side and right side of the boat. Side imaging was the first of this ultra detailed 3D view to be released.  Side imaging technology has been around for a while now and provides amazing detail.  I have been thoroughly impressed with side imaging since day one but it has always seemed very awkward to me because of the view on the screen (in contrast to the view or a traditional fish finder).



Down Imaging (Structure Scan)– Down imaging is similar to the side imaging view as it provides an ultra clear high definition 3D view but rather than looking at the left and right of the boat it looks down below the boat. This is much more similar to a traditional fish finder view but provides a much higher degree of detail and is 3D.  This in combination with the new HDS displays have been the latest advancements in fish finder technology. Most of the Lowrance units available now with down imaging also have side imaging capability.

down imaging

Down Imaging (Lowrance Structure Scan) Versus Traditional 2D Sonar – The image below shows the traditional 2D sonar view on the right (in color) and the left shows the new Lowrance down imaging and both are looking at the same image below the boat. The image on the right is obviously much different than the image on the left showing the trees under water.

structure scan comparison_thumb



Factors To Consider When Choosing a Fish Finder For Catfishing

There are a lot of “fads’” in fishing and a lot of fishing gear that gets marketed to catch fishermen, so I have tendency to keep new technology at an arms length until the bugs are worked out and it appears to be proven technology that really works. In addition, as previously mentioned the latest and greatest technology always comes at a premium price and then usually starts to drop significantly as soon as new models are about to be released.

For this reason I have been using the same fish finder for going on about seven years now but the recent technology that has been released has convinced me that it is time for me to replace my existing equipment.


  • Target Species – I previously mentioned this is my #1 tool for catching blue catfish but if you are a channel catfish angler it is less important. I still feel that everyone should have a solid performing fish finder regardless of species that choose to target to monitor depth, water temperature and find bait and structure but I rely MUCH less on my fish finder for channel catfish than I do for blue catfish. That’s not to say that I never use my fish finder for catching channel catfish because I certainly do but I am certainly much less depending on it when channel catfishing.
  • Budget – Your budget is obviously a primary consideration in choosing a fish finder for your catfish boat. These units can run from the low end of $200 to $300 to as much as $2500 (or more) depending on the features and units you choose.


  • New Vs’ Used – There are obviously advantages to buying new instead of used by assuring you have a solid performing unit with a warranty but buying used presents major benefits in terms of cost. With Bass anglers constantly chasing the latest and greatest gear you can often get good technology at an excellent price by buying a unit that is a year or two old (or more). If you are OK with having a solid performing unit that is a couple of years old then used may be the way to go. I will cover this more later in this article.
  • Color Vs’ Black and White – Color units provide a benefit as you can discern catfish from other fish when the fish finder is setup properly. Catfish will often appear as yellow arches in contrast to the other arches on the screen. With this in mind, I am currently using a black and white unit and some of the best catfish anglers I know are also still using black and white (grayscale) technology as well and do so with great success. With a little education you can discern catfish from the other fish using a black and white unit.
  • Traditional 2D Vs’ Side Imaging Vs’ Down Imaging – Traditional 2d technology is sufficient for catfishing in most instances and it has worked well for many others in the past. The new side imaging and especially down imaging is a game changer though. The level of detail and clear picture that it provides just blows my mind. Many of the newer units are offering the traditional view in combination with down and side imaging so you get the best of all three but these come with a premium price tag. There is also some new technology that provides the down imaging at a lower price point but eliminates the side imaging and traditional 2D view.
  • Screen Size – Screen size is a major factor for me because the smaller displays can be very difficult to see especially when you are trying to really zoom in to a detailed level. The fish finder I am currently using is one of the first big screen units that Lowrance produced. You can certainly get by with a smaller screen but having a bigger screen has huge advantages.
  • Pixel Rating (2D) – Some of the older units (if buying old stock or used) have varying pixel ratings. The less pixels the less detail you will get on your screen.


  • Brand – Lowrance, Hummingbird and Garmin are the three major players in marine electronics with Lowrance and Hummingbird being the two leaders. If you ask which is better among a group of anglers it is much like the Ford Vs’ Chevy debate (of course everyone knows Chevy is better). I have used Lowrance, Hummingbird and Garmin throughout the years but hands down my preference is toward Lowrance. They have solid technology that performs well and stand behind their products. **Disclosure – I have been on both the Lowrance and Hummingbird Pro Staff through my career as a catfish guide and am currently on the Lowrance Pro Staff. Lowrance has not compensated me in any way for these testimonials.


  • GPS – GPS is a major asset when fishing especially combined with the mapping cards like the Navionics card. The ability to see your boats location and relation to real time structure information is a major asset when catfishing for blue catfish. This combined with the ability to mark structure and locations for return on future fishing trips is a “must have” in my book. It is my opinion that every catfish boat should have a GPS unit. I use this for everything from marking under water structure to chumming and baiting holes and marking them for return to marking underwater hazards and dangerous areas on the water. The newer HDS units outlined above offer a much higher degree of detail on mapping but for the weekend angler a standard 2D mapping system is more than sufficient.


  • Additional Features Needed (HDS, Marine Weather, Etc.) There are a number of new features that have been added to the newer technology like high definition displays, the ability monitor weather through satellite radio, networking and many other features for more advanced use.

In the next Blue Catfish 101 article I will cover my top picks for fish finders for all budgets and features for 2011 covering both new and older technology.

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About Chad

Chad Ferguson is a professional catfish guide and founder of Learn To Catch Catfish. Click here to subscribe for more exclusive catfish fishing tips by email and then follow on Twitter or Google


  1. I really enjoy reading your articles Chad. I’m ready for the weather to settle down a little so we can get back to some leisurely fishing. I’m ready for some big fresh catfish fillets.

  2. I am at a crossroad in buying a new unit for catching blues. I am looking very forward in your next article comparing the different models

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