Side Imaging vs Down Imaging What’s best for your fish finder?

Every angler’s dream is to catch as many fish as they can. Thanks to numerous new technologies for fishing, like fish finders, an angler’s dream can be achieved. However, many anglers struggle with the direction of the sonar wave from a fish finder and are often confused about which sonar technology to pick for their fishing experience.

Not every fishing enthusiast knows the use and can distinguish between side imaging and down imaging sonar technology. The question most anglers ask is, “How do you know which sonar imaging to use on your boat?”  

To learn which of this method is best for your fish finder, read the guide below.

photo The Discovery Channel

What Is Side Imaging?

Different manufacturers have different names for this sonar technology. For example, Garmin calls it SideVü, Hummingbird calls it, Side Imaging and Lowrance calls it SideScan. They essentially perform the same task.

Side imaging is a sonar technology that uses razor-thin beams to project the depth of the water by giving broad coverage of the bottom of the water of both sides of your boat. The transducer functions at above 500 kHz and gives images of underwater activities and objects such as schools of fish, wreckages and natural structures.

How Does Side Imaging Work?

A fish finder with side imaging comes with a transducer which is placed outside the boat’s transom. The transducer comes with 2 solar beams, one on each side of the boat, showing up 240 ft. of water on each side of the boat.

Images on the screen might be difficult to understand without the right knowledge. Side imaging gives you a view of the bottom of the water, but the images are not in details. The thin white line that appears in the middle represents your boat. The dark bands or shadows on both sides of the screen is the bottom of the water and the water columns. Current images appear at the top of the screen and old images are gradually moved to the bottom.

How is Side Imaging used to Identify Fish?

You need to understand how each fishing accessory works to get the best experience. Since a side imaging is not an underwater camera it is essential to know that Images from SI are sonar returns and not actual pictures. Schools of baitfish appear as a cloud or constellation of small white dots, and large individual fish appear as little white lines on the screen. Ditches appear like dark shapes or lines, and rocks trees, grass, and other structures can easily be identified.

What Is Down Imaging?

Just like the side imaging, different producers have different names for the sonar technology. It could be called DownScan, DownVu or Down imaging. Whatever name it is called, they all have the same function, except for some slight changes peculiar to the brand.

Down imaging works like the traditional sonar technology and gives a clear image of the bottom of the water immediately below the boat. Down imaging gives a 180-degree view of the bottom of the water that means, it shows only objects and structures that are directly under the boat.

How Does Down Imaging Work?

Down imaging uses thin sonar waves and high frequency to produce a detailed picture. When in use, the transducer of the downing image produces sonic waves into the water. The sonic waves return back to the transducer and provide data about the environment underwater on the screen as a thin, upright plane. These narrow planes will then come together as the transducer is pulled through the water and provide you with a final image of the fish, structure and water column under the boat.

The water surface appears as a white crooked line. The lines are irregular because of the turbulence of your boat. Recent pictures appear at the right side of the screen and gradually moves to the left.

Unlike the side imaging, this sonar technology shows a clear and distinguished image of the bottom of the water and the fish in it.

How is Down Imaging used to Identify Fish?

A fish finder with a downing image requires a particular type of unit and requires a transducer that functions at the dual-frequency, of 455 / 800 kHz or 455 kHz.

This sonar technology sends down a thin layer of sonar and shows clear images and difference between underwater structure and fish. Schools of fish appear as white dots or specks and bait balls appear in the shape of a cloud, and weeds show up as lines, from the bottom.

So, which is best for your fish finder?

Both the down imaging and side imaging are great for improving your fishing experience. However, each of them is not without their disadvantages.

Side imaging is more useful in shallow bays and creeks. In areas like this, there are better than down imaging which is more useful for finding fish in deep waters. Side imaging is normally used to cover a wide range of water, while down imaging which obviously cannot capture a wide range because it focuses on the depth below the boat is a more useful in-depth range.

Down imaging gives a precise, clear and detailed picture of objects underwater even when your boat is on high speed, unlike the side imaging which is appropriate on low speed and gives a somewhat vague image.

Most down imaging sonars provide less information because they depend on one transducer. In contrast to side imaging sonar that can scan the water quickly and provide more details about the activities and structure underwater.

Both technologies have different uses that will improve your fishing experience. You can’t say categorically which of these sonar technologies is better. It is best to have both of these sonar technologies. But if you are to working with a budget, it is important to know that the decision of getting the best sonar technology depends solely on your need, the depth of water you will be fishing on, the size of the fish you want, how fast you want to go and of course your budget.

Author: James Cummings