How To Read Side Imaging On Your Fish Finder Like A Pro


Reading the side imaging on your fish finder can be really confusing if you don’t know what you’re looking at.

And even if you do know what you’re looking at, but you don’t fully understand how your device works, you might wildly misinterpret where structure or a school of fish actually is.

In this video, I’m going to share with you what different things look like on your screen so you can know what you’re looking at, as well as how your device works, so you can pinpoint where things are on the bottom.

If you want to get better at using your fish finder to catch fish, you’re going to love this video.

Let’s dive in!

How To Understand Side Imaging [VIDEO]

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When you first look at your screen, it can be very confusing.

What’s all the darkness in the middle?

Here’s a visual representation that really helped me understand how it works.

understanding side imaging

The darkness on your screen is right underneath your boat as your device scans out towards the sides.

So if you see part of a school fish on one side of the screen, as well as the other, that usually means that they’re right below you.

Now what happens if you look at your screen and most of it is black with just a little bit of color showing on the sides?

Well, the deeper the water you’re in, the wider the cone will be (the cone is represented in the picture above as the area under the folded up paper).

To see more of the bottom on your screen, you need to adjust the range in your device’s settings.

I like the keep the range at 40-50 feet on my device, which works for water up to about 20 feet deep.

Determining Where Objects Are In The Water

using side imaging

To determine how far away something on your depth finder is, you need to look at the numbers listed at the top of the screen, which are pointed out by the arrows in the picture above.

Those numbers are in feet, so you can tell that the boat is about 20-30 feet off to my right.

Another thing to keep in mind when determining where are objects are is knowing how the machine reads the bottom.

It always reads from top to bottom and there’s a slight delay, so, for instance, that boat in the picture above is actually behind me.

The slower you go, the closer the objects will be when they pop up on your screen, but if you’re flying through the water, by the time you see something you’ll probably be pretty far past it already.

Also, if you see a school of fish pop up on the screen when your boat is not moving, then they could be either in front or behind you.

The fact that the machine reads from top to bottom can throw you off if the school approaches from behind, so you’ll need to do a little searching both in front and behind you if you want to find that school.

What Objects Look Like On Your Screen

When you first get a fish finder it can be tough to know what you’re looking at, so below is an example of a school of fish

It’s a school of big black drum (one of those beasts is pictured below in the conclusion section!) and you can see the light spots where the sonar is reflecting off of them, as well as the dark “shadow” cast below them.

This was a clip from where I set my screen to just show one side, which helped me see more of the bottom, since my screen is small.

school of fish on depth finder

In the next image, you can see as I’m coming up on the fish, so there’s clearly a spot where there are no fish, and then where there are fish (which is circled).

side imaging school of fish

And in this final image below, you can see what structure looks like as you’re being still.

The machine is still scanning and the sonar is bouncing back, but since you’re not moving and neither is the structure, it’s not able to get an accurate read of the shape of whatever is down there.

side scanning structure

If this is happening, you just have to start moving again to get a more clear picture of what’s out there.


fish finder black drum

Although reading side imaging can be a little confusing at first, once you know what you’re looking for it can help tremendously in locating fish and structure.

If you want more help with reading fish finders, check out our Fish Finder Mastery course here.

You’ll learn everything you need to know about using fish finders to catch more fish, plus you’ll see actual on-the-water footage of these machines used to find fish.

Have any questions about side imaging?

Let us know in the comments below!

And if you know someone who wants to get better at reading side imaging, please TAG or SHARE this with them!

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William Dozier
1 month ago

Awesome video Tony! Just got the ability to sidescan and had no clue what I was looking at. Makes perfect sense now 💪🏼. Love the folded paper illustration; that’s perfect. Great work.

6 months ago

Its a good starter video, it would e great if you can show difreunits/brands

Delbert Young
8 months ago

Thanks Tony. You always give us great videos and tips. It took you a long time to figure all that out, so thanks for sharing your knowledge.

9 months ago

Great video on side scan. I would love to see one on regular sonar

Tim McManus
9 months ago

Tony, this is the clearest explanation of side imaging I’ve seen. Very helpful. Thanks.

9 months ago

Thanks Tony.

9 months ago

good report

Michael Moran
9 months ago

Great video Tony! Thanks

Capt Roy Bennett
9 months ago

Hey Tony, I enjoyed your video and picked up a couple tips, however, no matter how I change my settings, depth, etc. on my Garmin I am still not seeing images on my screen. I have vague darkness on both sides regardless of the speed I go. Any thoughts?

Bennie Thomas
9 months ago

Thanks Tony, My son tried to explain the Side Imaging to me and I couldn’t quite understand it. The folded paper and the pictures of the boat and fish helped me understand it. I will get to try it out on Friday and see if I can determine what’s on the screen. Thanks again.

9 months ago

That black area is quite annoying to me. Some of the newer units allow you to play with the settings to eliminate that black (or i guess we could call it depth) area. The hummingbird solix models offers this and i wish i had that unit. So what is 10’ to the right of the center line, shows as 10’ out, without eliminating the depth, it can appear to be 30’ to the side of you when you are in 20’ of water.

Awesome job here Tony.

Randal Houghton
9 months ago

Thanks Tony, great video. I fish Redfish Bay in Texas, and typically like to set up slow kayak drifts in water that predominately runs 2-3 feet. Looks like fish will look like spaghetti then. Is it best to go with slow trolling or just the silent drift (my natural preference). Am I reducing the usefulness of a potential side sonar by preferring silent drifts? I prefer to pick winds in the 12-16 mph range so I’m not moving at speed at all, especially dragging a bait bucket and/or cull net.

Randal Houghton
9 months ago
Reply to  Tony Acevedo

Thanks Tony, your answer was very insightful. You make this sight fantastic.

Larry Widdifield
9 months ago

That was excellent. Need to get mine working properly to see the details you show in this video.

9 months ago

Great info, the folded paper prop is the easiest way for most folks to wrap their mind around what they are looking at on their screens.

Curtis Hebert
9 months ago

Great video Tony. this was very helpful as I just invested in a side scan unit. I have only used it a few times. Now I will know how to change the settings and be more confident in what I am seeing.

Howard H Wemple
9 months ago

Thanks Tony always wondered if those units could help, now I know they would be a great help!

Robert Bonsey
9 months ago

Great Video

Glenn Acomb
9 months ago

Thanks Tony. This was a very good video. I would suggest that Salt Strong could take this further into more examples of images at different depths, fish and structure. Thanks.

Herman Pellegrin
9 months ago

Thanks that is a very good explanation, very helpful.

Bill Brown
9 months ago

Thanks Tony. This is a great explanation.

9 months ago

Great job. The folded paper analogy is very effective as an explantion tool. Might you consider doing another video or two with a variety of screen shots? For example, looking under docks, some of which are holding fish and others not holding fish; looking at bridge pilings; scanning man made reefs in fairly shallow water, etc.
Many thanks!

Robert Spangler
9 months ago

Good deal

Don Mace
9 months ago

When looking at the bottom the harder the bottom the brighter white it will be, at least when using the blue color palette. This is extremely helpful when you’re looking for a wreck. Most wrecks coordinates are not exact so adjust your range out as far as possible and scan the area until you see bright white areas out to the side. Then drop a waypoint, navigate to it and switch over to downscan.

Bob Alexander
9 months ago

As always, another home run from Salt Strong. I got my side imager a few months ago. Here are some hints from my early experiences. The first thing I did with it was cruise areas where I could see above the water what had to be below it: docks, pilings, crab traps, anchored deep-draft sailboats, deeper water near mangroves, etc. Turned it on while surrounded by a school of mullet, porpoises and even a manatee. Watch your depth finder and cruise parallel to the drop off along a channel and compare the depth vs. side imaging on a split screen if you can. Enjoy your tool; you paid for it!!

9 months ago

Great job as usual Tony.

9 months ago


Rob S
9 months ago

Well done, Tony; Best explanation I’ve come across. The image showing a sunken boat – – the black area shows 10′ on each side with a depth of 11.8′. Moving to different depths and observing the width of each black area might be a way to roughly calibrate. Might be interesting to setup two floats each having yellow “Caution” tape with a weight to hold on the bottom to see how this image displays on the screen relative to the black area, for example.

Robert Knowles
9 months ago

Hey Tony that was great. Thanks for actually simplifying the process. Definitely the best I have seen. Not as intimidated by purchasing and using one. Thanks

Cory R Ponz
9 months ago

Thanks Tony!! GREAT LESSON. Always been confused on the side imaging. I understand it now. Looking forward to using it better! You’re AWESOME !!!!

Vincent Haramut
9 months ago

Very good explanation on side view video !!

Jim Esher
9 months ago

thanks Tony. There’s a lot of confusion (other online you tube videos) with regard to the depth (black area) being calculated in the side scan distance as it appears on the screen. Ex: Add the depth to the side distance so in your case with the boat image it would actually be 20-30’ plus the depth. Like to get your take on this.

Jim Esher
9 months ago
Reply to  Tony Acevedo

Thanks, yes your explanation makes sense which was my understanding however I came across a u tube video that was indicating that the depth needed to be added to the side scan distance which seemed odd to me. So let’s say it’s at 25’ in side scan (port side for this exercise) but your in 25’ of depth their statement was the distance where the object sits on the port side is actually 50’ away from you. Ever hear this before

9 months ago
Reply to  Jim Esher

Jim, your explanation is how i think it works.

Dwayne Hubbs
1 month ago
Reply to  Tony Acevedo

Tony, thanks for taking time to help explain side scan views. I must say though I believe that you are mistaking on how to translate the distance the item is you are viewing to the side of the boat when the sonar is not set on contour mode. First of all, when viewing side scan, the sonar is not shooting a cone from the transducer to the bottom. It is shooting a “razor thin beam” to the sides. So when translating how far away from the boat is to get a more accurate distance the user must subtract the water column from that distance. In other words, if your water column shows 20 ft of water under the boat, and you see a fish or any other object say 50 ft. to the side then you must subtract the 20 ft. water column from the 50 ft. which puts your object at 30 ft. to which ever side your seeing it. When you put your side imaging on contour mode it will show this to be true by eliminating the water column below the boat. In contour mode it will show that same object 30 ft to the side by eliminating the water column. Viewing side scan imaging with the water column showing, simply makes it much easier to see fish directly under the boat, but consideration on distance must be made when in this mode viewing images to the side to consider distance from the boat. Deml
9 months ago

Tony great video. Can you do a video of how to install the fish finder with SI. I am thinking of that will be my next upgrade, just wondering what issues I might have.

Joseph Brumley
9 months ago

Great info Tony. Very informative. I’m in the market for a fish finder for my kayak and have been watching the fish finder mastery course and learning a lot. Do you have Down Imaging on your unit also? If you do which do you use more, DI or SI? Getting a unit with both is quite expensive. I’m not sure whether to get a unit with just DI or go ahead and bite the bullet and spend the extra dough and get a unit with both.

Joseph Brumley
9 months ago
Reply to  Tony Acevedo

Thanks Tony. I do believe I will get one with side and down imaging. Seeing how most of the kayak fishing is in less than 10’ of water the side imaging makes a lot of sense. My home lake 90% of the water is 30’ so I also really want a good view of what is beneath me so I need the down imaging as well. Yes I noticed the big bulky transducers and since the kayak has been known to scrape bottom a lot that is a concern. I’ll have to research several options for mounting it.

Joseph Brumley
9 months ago
Reply to  Tony Acevedo

Tony, I bit the bullet last night and bought a Garmin ECHOMAP Plus 73SV. It has down imaging, side imaging and a ton of other features. I fond it online at Bass Pro Shops/ Cabela’s on sale for $449. Great price for all the features. I researched mounting it and have a couple of ideas but I’m going to wait until I actually have the unit in hand to make a final decision on how I want to mount the transducer. You’re video and the fish finder mastery course were great sources of information in my research for a new fish finder. I had a much better understanding of what they do and what I wanted. Thanks again.

David B. Stoots
9 months ago

Very helpful. One of the best posts I’ve read and definitely one of the best on this subject. Would like to see more about effective use of the MFD’s. Thanks for sharing that.

Edwin Kolodziej
9 months ago

Tony if you see a rock pile or other structure on your machine can you move the curser to that spot and mark it as a waypoint so you can get back to the exact location?


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