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Sonar, Down Imaging, Side Imaging and 360 Imaging For Catfish [CR EP 26]



In the last episode of Catfishing Radio we discussed bank fishing for catfish tips and common mistakes focusing on increasing the success of anglers fishing for catfish from the shore, regardless of which catfish species you target. In this weeks show we are flipping things around a bit again and focusing on the catfish boat anglers and discussing different sonar technologies along with choosing a fishfinder for catfish.

If you are looking into purchasing electronics for the first time or considering upgrading the existing equipment on your boat, there is valuable information on this Catfishing Radio podcast.  This will help you better understand the different technologies and make a more informed decision when purchasing.

We start the show off by discussing the different technologies, down imaging (or down scan), side imaging (or side scan), traditional 2d sonar (broad band) and the latest and greatest technology, 360 degree imaging and outline each of these different technologies and how they pertain to fishing for blue catfish, channel catfish and flathead catfish.


2D Sonar (Broadband)

2D sonar or broadband sonar is the typical sonar technology that has been around for year. This shows the bottom contour, arches for fish, bait fish and gives you a good picture of what is going on directly below the boat when you pass over an area. This is an essential tool if you are going to target catfish (especially blue catfish). Older units are available in black and white and newer units have color screens that provide a higher level of information due to their color readouts.


Down Imaging and Downscan

Down imaging or downscan technology also looks directly below the boat (like traditional 2d broadband sonar) but provides a much more detailed picture. It allows you to see more definition in the fish, structure and cover below the boat and provides a much clearer picture.


Side Imaging and Sidescan

Side imaging or sidescan shoots a sonar beam on either side of the boat (or one side if you choose that option in the settings) and gives you a highly detailed image of what is on either side of the boat. This allows you to see cover, structure and even balls of threadfin shad and gizzard shad. The side imaging range is adjustable on most units and allows you to see out as far as several hundred feet but to get a clear picture with detail that is usable you have to look at a much more narrow range.


360 Degree Imaging

This is the latest technology from Humminbird. The 360 degree imaging technology provides a highly detailed image (like side imaging and down imaging) of everything below and surrounding the boat and will function while sitting still. This is a new technology that comes with a premium price tag.


Choosing a Fishfinder For Catfishing – What Features To Look For

I am constantly getting phone calls, emails and talking with clients who fish with me at North Texas Catfish Guide Service who have either just made a purchase of one of these technologies or are about to make a purchase. The technology is confusing and they often come out with what I consider to be a waste of money or a bad purchasing decision not giving them the features they need.

These opinions are based on my long term use of the Humminbird 1198c and the different features available.

Brand – My suggestion is to stick with Lowrance or Humminbird, nothing else.  They are the two undisputed leaders in this market. My preference is Humminbird because they are made in the USA, everything is self contained within the fishfinder for installation (except the transducer) and Humminbird hastop notch customer service (something Lowrance has really struggled with for a long time).

Screen Size – When using down imaging and side imaging screen size has a MAJOR impact on the functionality of the unit and being able to really see what is going on. Always go with the biggest screen possible.

2D Broadband Sonar – I am of the opinion that this is still one of the most valuable technologies when it comes to locating catfish and bait fish. I suggest a color unit but black and white is better than nothing.

Down Imaging – There are some benefits to down imaging and the higher level of detail really helps when fishing around heavy cover. It is much easier to see schools of bait fish and helps with catching bait. I am of the opinion though that nobody should purchase down imaging only and I don’t feel that down imaging should be purchased without side imaging.

Side Imaging – Besides 2D sonar side imaging provides the biggest benefit for catfishing. Being able to scan and view large areas of water on the sides of the boat make it much easier to locate and target catfish instead of only being able to see below the boat. Besides 2D broadband this is the biggest bang for your buck.

360 Degree Imaging – New technology from Humminbird that starts shipping in August. Comes with a premium pricetag of ~$2000.00


The Bottom Line

A black and white broadband sonar is better than no sonar, but color provides more useful information. Go with color if possible.

Down imaging is cool but without side imaging, I would not spend the extra money.

Side imaging is the best feature with the biggest impact but you need a large screen to really benefit.


Fishfinder Models To Consider and Buying Advice

  • Humminbird 586c – Bottom dollar 2D broadband sonar in color. This is an excellent entry level product.
  • Humminbird 998c SI – 2D Broadband, GPS, Downscan and Sidescan and a large viewable screen.

I am of the opinion that these are the best two options on the market at this time for a basic 2d broadband unit and an all in one unit with side imaging, down imaging etc. There is a vast difference in pricing but after recently helping some others with the smaller screens and side imaging/down imaging, I am of the personal opinion that you should not spend extra money on the down imaging or side imaging without going with a large screen.

If the Humminbird 586c is out of your price range you can also look for fish finders on eBay and find some older models. Again my suggestion is to go with only Lowrance or Humminbird, get the largest screen possible and get the highest number of pixels you can find.


Want to take your fishing to the next level and learn step by step in clear easy to follow instructions, check out our premium products page and our products like spring blue catfish techniques, summer channel catfish techniques, the secret channel catfish rig, jug fishing 101 and splat fishing techniques for more information!

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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`ve never used a finder but have been thinking about it- i`m 72 now & this is a big concession for me-this means depending on something other than myself- i will do it & this helps make the decision GOOD FISHING

  2. butterbean carpenter says:

    Howdy Chad,
    Couldn’t a bank fisherperson(PC) put a transducer on a float, anchor it with a long pole, run the coax up the pole to the bank/dock and use the fishfinder??? That way you’d know whether you had a ‘fishy’ place or not!! Just thinkin’ and I ain’t even got a box!!! Well, I am a square-headed kraut!!!

  3. I have an 898c si and agree on the screen size issue, mainly
    because the data bar on the left hand side eats up so much room.

    Humminbird has addressed that issue with thier latest software upgrade
    and now that data bar can be removed.

    Cudos to bird for listening to fisherman. Viewable screen size after the update is bigger than a 998 without the new software. Still smaller
    than I would like but that’s all my budget wanted at the time.

    Mo river fisherman here, but still enjoy your podcast. Makes that day
    at work a little more enjoyable.

    Thanks for the good work.


  4. well i was looking forward to listening to ep 27 but when i clicked the link above it was ep 26 that started playing and just finished listenint to it. is there an ep 27 yet? cant wait

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