In this article, we’ll walk you through the basics of how to read a Lowrance fish finder so that you can start catching more fish today. The below guide is applicable to Lowrance HDS Live, Elite FS, Hook Reveal, and basically any Lowrance model that uses the traditional fish finder techniques.
How to Read Lowrance CHIRP Sonar
2D Sonar is composed of different colors to indicate the fish and structures below the boat. The colors represent the intensity of the sound pulse returned from the transducer. In this example, yellow represents the strongest return and blue is the weakest. You can also select different color pallets in your Lowrance.
In the first screenshot above, there is Yellow at the top. This is surface clutter. At the bottom, you can see Yellow and Red, which represent the hard and soft bottoms of the water, respectively.
The thickness of the line at the bottom indicates how hard the bottom is. A thick Yellow bar (our strongest return) will suggest the bottom of the water is rocky and not soft like sand or silt. But thickness can also be affected by the sensitivity of the sonar. At 100% sensitivity setting bottom may appear very thick and at 10% it might be very thin.
A fish on your sonar screen will look like an arch or a straight line like a worm.
When the transducer passes over a fish or the fish goes through the sonar beam, a fish arch will develop. If a fish enters one side of the beam and exits through the other, passing through the center of the cone, an arch will form. The fish arches are usually visible when the boat is moving at the speed of roughly 4 – 6 miles per hour.
Otherwise, if the boat is stationary and the fish is also still, straight squiggly lines like worms are formed on the sonar screen.
How to Read Lowrance DownScan
DownScan Imaging is a great tool for finding fish, especially when fishing offshore around rocky areas or ledges. With DownScan, you get a much clearer picture of what is below your boat, making it easier to distinguish between fish, rocks, and other structures.
DownScan returns are typically displayed vertically, similar to 2D sonar readings. The most recent information appears on the right side of the screen.
To best read DownScan data, remember that the strength of the sonar return determines the shade of the image. Softer objects or bottom terrain produce weaker returns and dark shades. Harder bottom terrain or objects generate stronger returns and light shades.
DownScan Sonar is an impressive technology that can even show you individual fish. Fish schools will show up on the screen as a tight cluster, while individual fish will appear as solid marks.
Lowrance has a Fish Reveal feature, if activated, makes fish appear as arches instead of solid marks. This feature is available in the Lowrance Hook Reveal, Elite FS, and HDS Live Series.
How to Read Lowrance SideScan
Most anglers find it difficult to read a fish finder, especially when it comes to understanding the SideScan feature. However, with a little practice, you can learn how to use this technology to your advantage.
SideScan imgaing is different from traditional 2D sonar. The sonar history moves from top to bottom, instead of moving right to left. This means that the most recent areas you’ve passed over are shown at the top of the screen.
The boat and transducer are in the center of the screen and the transducer beam is displayed as the white line running down the screen.
The dark area in the center of the screen is the water column that is directly under the boat. The colored area on the left and right sides of the screen is the waterbed. It represents everything that is on the left and right sides of the boat.
The different shades produced by the Lowrance SideScan imaging can help you see what’s below your boat. The brighter the color, the stronger the return from the object below. For example, a softer bottom or deeper water will appear in darker shades, while a hard bottom or shallower water will appear lighter.
Shadows are another thing to look for when reading Lowrance SideScan. Imagine a flashlight beam shining on the objects in the water. If an object is huge, it will produce a very large shadow. Smaller things will generate smaller shadows.
Fish are usually found around structures. After you have identified the structure by examining the shadows and different shades of return, it’s easier to find fish.
How to Read Lowrance Structure Scan 3D
- Depth and temperature
- Transducer beam
- Depth indication line
- 3D panel buttons
- Zoom panel buttons
Lowrance StructureScan 3D displays an image of the sea floor directly under your boat in real time. You can see other underwater objects and clusters of fish. The 3D view shows both the left and right channels of data.
Objects in the water column are identified as dots. Similar to DownScan and SideScan, fish are displayed as dots or marks. The color of the dot corresponds to the strength of the return by the object. Big Fish and Fish Schools are generally displayed with bright colors with strong returns.