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How to Read a Fish Finder 

Last Updated: 01.12.23


Boat fishing and kayak fishing can be extremely rewarding, given that you are familiar with its challenges, so make sure to check it out here for more information on how to properly use the right gear to find the biggest fish in the sea. 

Having a successful fishing trip requires time and preparation so that everything goes smoothly while you’re on the boat. Apart from packing the right rod and reels according to the type of fish you plan on catching, as well as sporting the appropriate clothes and having some snacks to keep your hunger away, you may also need the help of special tools to lure in fish or find where they are hiding. 

In this case, casting a fish finder can help you easily identify the best fishing spot, saving you time and energy. If you’re a beginner and not sure how to accurately read the device, here are some easy tips and tricks that will help you master the fish finder in just a couple of hours. 


What is a fish finder?

Understanding how the device works is part of the process, so start by knowing exactly what it does. According to fish specialists, a fish finder is an electronic device that uses sonar technology to show objects that are under the water. Most of the devices on the market come with built-in GPS units to enhance their accuracy. 

Although the fish finder is made of various components, one of the most important ones is the transducer, as it has direct contact with the water. This component is usually positioned at the lowest part of your boat or kayak, and it is responsible for tracking down fish. 

If you’re wondering how the transducer works, the process is quite easy. It sends an electronic pulse into the water and, if the pulse encounters any movement or object, it will return to the receiver. The time the transducer takes to return the signal determines the type of object found inside the water. 

Apart from that, a fish finder also uses specific software that analyses the signal received, transforming it into an image that will pop on the product’s screen. However, the image isn’t very clear and you need skills to properly read the screen and identify where the best fishing spot is. 


Tips to use a fish finder and how to read it 

The first and most important thing is to identify where fish is, and the fish finder can help you do so. Generally speaking, the screen of your product is user-friendly and, with the right training, can help you identify the best spots for fishing. 

Your fishfinder comes with a fish ID to help you locate the fish icons. The icons appear in different lengths and shapes, so you can easily differentiate fish from plants, rocks, and other items found underwater. Keep in mind that you have to identify the right icon on the screen, as well as its depth, to know exactly how to cast your reel. 

Once you identify a signal from the transducer, you will most likely see it on the screen of your device in lines and arches. The image in the form of arches is usually clearer and easier to read than fish IDs. For instance, if you notice a big arch displayed on the screen, most likely you are dealing with a large fish right below your boat. 

Sometimes, getting to read the arches will be hard, and you can mistake fish for rocks or other objects underwater. The key is to continue practicing until you get it right. 


Judging fish size 

Not everything that appears big on the screen translates into a big fish, so you need to pay attention to these details too. Sometimes, further analysis of the displayed arches is required to determine the true size of the fish and make sure it is worth your while. 

Properly reading the arches also involves knowing about their length, width, and type. The length of the fish arch fails to show you exactly how big the fish is, but the width can give you more information. 

Generally speaking, you should consider the vertical and not horizontal arch when reading the fishfinder’s screen. Regardless of the length of the arch, if it is thick, then your fish is big. Thus, the thicker the line, the bigger the fish underneath your boat. 


Identifying various types of underwater structures

Learning how to properly read a fishfinder will also tell you more about the depth of the water and, therefore, you’ll have a clue about the type of fish you can catch. 

The depth of the water you’re currently sailing in can be found at the top corner of the display. The measurement unit is set by default in meters so, if you’re used to feet more, you’ll need to change the settings. Don’t forget to also reel your device at slow speed so you can see the contour of the bottom. This is the easiest way to identify drop-offs. 

After you got your drop-off, you should consider scanning the area again, this time using a slimmer beam. This will help you avoid dead zone areas during your scan and enhance your overall fishing experience. 

Alternatively, you can choose to set up a depth alarm if you’re paddling in a large area so that you know exactly when you reached the chosen depth, depending on the type of fish you’re looking for. 

Keep in mind that each structure you find underwater sends a different frequency to your sonar, which is later edited into a different color. Knowing the color palette will have you easily identify logs, brushes, and fish when casting your fishfinder. 


Other underwater objects

As we previously mentioned, learning to properly use a fishfinder takes time and practice. When it comes to vegetation and weeds, you might want to head to one of these areas to fish for your favorite species. The fish finder works great in these areas, so you will have an easy time separating your prize from other underwater objects. 

If you’re fishing for carp, you’ll most likely target depressions. A depression will be marked on your device screen through a small v-shape dip at the bottom. When you reach that mark, you can start looking for carp. 

Keep in mind that you might stumble across unusual objects during your fishing trip, so you need to be patient and know how to identify the type of object based on the signal it transmits. 

Use the shape and the strength of the return signal to determine, at least partially, the object below your boat. If the object is really heavy and hard, you’ll notice the repetition of the return signal on the screen. 


Tips for reading the fish finder 

We previously tackled some of the easiest ways to make the most of your device and identify fish easier when fishing. However, there are still some tips that will enhance your experience, so make sure to follow them.

The first and most important is to carefully read the manual and follow the instructions. Most of these devices come with thorough instructions so you can easily understand and learn how the fish finder works. 

Secondly, try to understand the exact model of fish finder you’re using by practicing with it. What you learned previously are some general guidelines on how fish finders work but you need to consider that each model is unique. Sometimes, even small differences like screen resolution, brightness, or size can impact the user experience. 

Also, don’t be afraid to switch to a different model if you cannot get used to this one. Not all fish finders will work with newbie and professional fishermen, so the key is to identify the model that best suits your abilities. 

Another important tip is to first use the device in an area you are familiar with, preferably a small pond or creek. Try to figure out how some objects appear on the screen so you can later identify them in other areas, and finally reach the best fishing spot. 

Finally, change the color palette according to your needs, and don’t forget to also adjust the sensitivity of the transducers and the update speed. This will improve the accuracy of your readings. 



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