Choosing the right fish finder depends on the type of imaging you need. In fish finders, there are two types of imaging available, side imaging and down imaging. It is the way sonar receives information that makes the difference between the two. Down imaging detects objects below the surface, while side imaging examines the sides of the boat or vessel using sonar. The aim of this article is to explain what the differences between these two types of imaging are and what might be the best option for your situation.

What Is Down Imaging?

Down imaging is the use of sonar to detect objects under the surface of the water. It works by sending out pulses of sound waves into the water and then listening for any echoes back from the object(s) in the water. When an echo is detected it indicates there is something in the area where the sound was sent. In most cases this means there is some sort of underwater structure such as a rock, coral reef, or other submerged object.

How Does Down Imaging Work?

Through the water, sound waves (pulses) are sent until they reach solid objects in down imaging. Refractions occur when sound waves hit solid objects. A receiver then picks up refractions, converting them back to sound waves. Digital data is displayed on the screen when the sound waves hit solid objects.

Down imaging has several advantages over side imaging.

  1. First, it allows the user to see things that are not visible with side imaging. For example, if you were using side imaging you would have no way of seeing the bottom of the lake or ocean because the bottom is covered with sand, mud, rocks, etc. With down imaging you can see all of those items.
  2. Second, down imaging allows the user to see more than just the top few feet of the water. You can see everything from the bottom of the lake to the depth of about 100 feet.
  3. Third, down imaging does not require a line-of-sight connection between the transducer and the target. This makes it possible to use down imaging even if the boat is moving. Fourth, down imaging is very accurate.
  4. Finally, down imaging is much less expensive than side imaging because it can distinguish between rocks, reefs, and wrecks.

Down Imaging Disadvantages

There are disadvantages to down imaging as well. First, down imaging requires a clear view of the bottom of the body of water being searched. In addition, down imaging cannot detect small objects such as bait fish and insects if the bottom is muddy or rocky.

What Is Side Imaging?

Side imaging is the use of a transducer to send out sound waves and listen for reflections off of the sides of the boat. Like down imaging, it also detects objects below the surface but it only looks at the sides of the vessel. As a result, it provides a limited amount of information compared to down imaging. However, it does provide a good deal of information.

How Does Side Imaging Work?

Side imaging uses a transducer to transmit sound waves into the water. The sound waves bounce off of the sides of your boat and return to the transducer. An electrical signal is converted from the sound waves by the transducer and displayed on the fish finder’s screen.

Side imaging has several advantages over down imaging. First, it gives the user a 360 degree view of the surrounding area. This includes both above and below the surface of the water and around the sides of the boat itself. Second, it is much easier to operate since the operator does not need to look directly at the bottom of the lake. Third, it is much cheaper than down imaging.

Side Imaging Disadvantages

Like down imaging, side imaging has its own set of disadvantages. First, side imaging will not work if there is too much interference in the area. This means that if there is a lot of wind, rain, snow, fog, or other weather conditions that could interfere with the operation of the system. Second, side imaging is not as accurate as down imaging. It is capable of detecting large objects such as boats, buoys, and docks but it cannot tell the difference between them.

Third, side imaging is not nearly as easy to operate as down imaging. If you want an accurate reading, you must hold still and look straight ahead.

Which One Should I Use?

The best choice depends on what type of fishing you plan to do. If you want to catch bass, walleye, catfish, or any other kind of fish, then down imaging is the best option. It is much better suited to catching fish than side imaging. On the other hand, if you want to search for specific kinds of fish such as trout, salmon, or perch, then side imaging is the best choice. It is much faster and easier to use than down imaging.

Frequently Asked Questions:

Q: What is the right imaging system for me?

A: A decision has to be made about whether you want to go fast or stay safe. If you want to go fast, your best choice is probably down imaging. If you want to stay safe, your best choice probably is side imaging.

Q: Can I Use Both Types Of Imaging Systems At Once?

A: Yes, you can. In fact, most fish finders today offer both types of imaging systems. They usually allow you to switch back and forth between them depending on which one you prefer.

Q: Does My Boat Have To Be Level?

A: No, your boat doesn’t have to be level. Most fish finders today include leveling devices so that you don’t have to worry about this issue.

Q: Will Fish Finders Work Underwater?

A: Yes, they will definitely work underwater. Some models even have special waterproof housings that make them perfect for use underwater.


Today’s fish finders are far more advanced than those available just a few years ago. They are far more advanced than those available just a few years ago. Before making a purchase, make sure you are clear about what features you want, whether you are using them for recreational purposes or for commercial purposes.

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