Fishfinder is a great device for finding fish that makes your fishing trip easy and enjoyable. It can locate fish, water depth, other obstacles, shallow waters and has an underwater sensor that continuously sends information that you can see in the display. It has a color screen so you can see fish activities and move easily. This device is very handy, so you can install it in your boat at any time and easily focusing on it while fishing.
The technology of fish finder upgrades day by day includes various options that make your fishing more comfortable and fun. This can locate fish in the ocean, river, and lakes for fishes and detect schools of fish in any area. Knowing how it works is not difficult. Here I will write its working system most efficiently so you can understand better.

Types of Fish Finders
There are different types of fish finders available in the market. Each of them is different and offers a different depth to count. Also, they are made for different kinds of freshwater and saltwater fishes. The types of fish finders are,
- The normal 2D fishfinder
- Down imaging fish finder
- Side imaging fish finder
Some fishfinder has all the combination as well as a different basic function. You should know how they work to decide which one you should buy. They also have some disadvantages, so more or less so keep your mind open for deciding.
2D Fish Finder
It is a traditional old-time standard fish finder that is very easy to read and use. It has a scrolling system so you can notice almost everything under the water and identify fish. Although detecting fish is a little difficult here. The fishes are shown in the display like a dot or a dash in a bright color.
Down Scan Fish Finder
Downscan fish finder is great for shallow water fish. It gives a downright realistic view to detect fish and their movement easily. The hard rock may not be seen in the display clearly, but the fishes are pretty much visible.
Side Scan Fish Finder
This fish finder is mainly for professionals. It gives a photorealistic view and covers around your boat. Hidden fish are easy to detect here. This is a perfect fish finder for deep water.

Fish Finder Basics
Most of the fishfinder has the same option such as GPS, GPS receiver, transducer, networking device, Bluetooth, etc. Those accessories are consisting of two main parts: the computer display and the transducer.
GPS and Chartplotter
The advanced fish finder has a GPS that improves performance and navigates your boat to a specific point. You will certainly enjoy perfect sound navigation and ranging in the top fish finders’ model, making sure the result is accurate in the depth of the water.
You will get a sea map on display and know which way to go. Some high-end model has Chartplotter with GPS that gives you the option of easy moving and explore. The GPS receiver will show your boat position if you are at low speed. You will also be able to return the previous point.
Screens
The different fish finder has different type and size screen. If you use a bigger screen, you can see more information. A 9″ screen is perfect for seeing the details. The pixel density is also important.
The bigger the screen, the less pixel density you will get. the 5″, 7″, and 9″ display has the best regulation. It is called the head unit of the fish finder.
The Networking
Professional anglers use multiple fish finders to get more information. Multiple fish finder needs networking to cover more area, but you also need a bigger boat for it. However, it is hectic to manage all the screens at the same time standing in one place. If your fish finders are different brands, you have to network them properly.
How do Fish Finder Works?
Fish finders are basically use for finding many fishes in the deep water to locate where to cast your bait. To use it properly getting for anglers, one should understand how it actually works with knowing fish finder basics.
How the Display System Works
The fishfinder device has 3.5 to 16-inch displays that show you the location of fish and other obstacles. But how it shows all of this? The display has sonar features and a transmitter, and they both work with the waves.
First of all, the transmitter sends a signal to the waves using the aspect of echoes. The signal of the waves reflects and comes back to the transmitter. There are fewer possibilities to receive a false signal because the signal will always reflect in the fish or other obstacles.
The aspect of echoes works differently in a different object. It shows different symbols of fish or other things.
You need to know the meaning of symbols or how the fishes look on the screen. The display will give raw data.
How does a Transducer Work?
The transducer works as eyes and ears for a fish finder. This section helps to detect things around or under the boat you see in the display because the transducer sends the data to the software, and the software shows it to the screen. Different types of transducers work almost the same.
It has piezoelectric crystals elements that vibrate at specific frequencies and produce sound waves then send through the water. When the sound wave starts, it goes bigger and creates wider beams into the water.
So, the beams can hit and reflect something in the water, which could be fish or other obstacles. The beams reflect the fish finder after it hits the fish. The fish finder measures the distance and sends the detailed info to the display.
The reflected beams return to the fish finder in a very short time, at least 12 times per second. The fish finder also measures the shape of the object. You will get different frequencies in the different transducer. So, the transducer does all the works under the water.
How Sonar Cones Work
The fish finder sends sonar beams that go into the water in shape. It could be cones or direct lines. That does not mean it can only detect fish that comes into the sonar area. The sonar can detect the fish in the wide and deeper area as the sonar directly scan in cones that go deep.
First, the sonar sends sounds in waves, and the waves make it in cones to make the beam wider. It can also change the beam frequency to control the range to use it in a different place. All types of areas are not effective under beam cones.
The wider the beam, the more depth information you will get on the display. Like fishing from a kayak or boat using trolling motor, the depth information can come in handy.
However, it may miss some details. Beam cones are effective in shallow water as it covers a wider area and you see more objects. However, the picture will be fewer regulations. The smaller the beam, the more precise picture you will get.
Fish Finder Tutorial on Surface Clutter
Sometimes sonar detects fish or another object close to the surface. This is called surface clutter as the sonar reflects too fast and creates noise when it hits currents or bubbles.
This situation creates a blind zone, and the sonar cannot detect fish. High-frequency sonar cannot create much blind zone, so the higher it goes, the wider it can cover the area. Use a broad beam to find fish from deeper. If your fish finder detects any fish, scan it few times to locate it.
How to You Read a Fish Finder Screen
Reading a fish finder is not much technical. You will know the depth of water, the shape of obstacles to decide which tools or bait you should use.
How to Detect Fish in Rocky Area
In the fish finder screen, you will see many boulders when you are in a rocky area. When the sonar beam hits a big rock, it reflects only on one side of the rock, and the sonar won’t reach on another side. So, the screen will show a shadow. If there is any fish, your fish finder will show it on the screen.

How to Detect School of Fish
If your fish finder has traditional sonar, it will show fish arches on the screen, and the other structure will show in downs.
The traditional sonar can detect trees, rocks, or other obstacles very well. If there is any school of fish, it will show large arches. For inshore fishing, using the inshore fishing reels, these fish finders work perfectly.
However, traditional sonar is not good for detecting smaller fish. You will see only dotted on the screen. If the screen is down scanned image, it will show the fish as a blob.
If the fish arch is thicker, it means the fish is big. Although detecting the size is depends on the depth of water. If you are in a deep-water area, the arch will show little on the screen.
Detecting Hidden Fish in Fish Finders
This device also works in boats and can make an accurate finding in moving water as well. If your boat is in a highly structured area, it will show bright color on a traditional sonar screen. The mixture of high weeds will be yellow and red, and fish is also red if they are heading near the weeds.
But in the down scan image, the mixture of weeds color will be light blue, the background will be black, and fishes will be shown in red. If the fishes are hidden in the trench or moving in fast water, the down scan image can show them. In traditional 2D images, it isn’t easy to show.
Fish Finder Work of 2D Sonar Icons
2D sonar works like a cone-shaped beam, and it picks up everything that is inside the cone. So fish will look in arches, round marks, the hard bottom will show yellow and mucky bottom will show orange color in 2D sonar. Baitfish are looked like clouds, and large fish will show solid color on the screen.
Down Imaging Sonar Icons
Down imaging sonar shows realistic pictures on the screen. Fishes of 2D sonar and down imaging sonar almost look the same, but the symbols will be smaller than 2D sonar in the down image. Schools of fish will be a little larger.

Hard bottom symbols depend on the color palate. The hard bottom color will be mostly dark blue, and the soft bottom will be light. However, the color depends on the different bottom.
Side Imaging Icons
Side imaging displays are difficult to detecting fish. So, it only covers one side. The icon will show a little blur.
Does a Fish Finder Have to Be in Water to Work?
Engineers mainly create fish finders to work them in the water. So it is not possible to use a fish finder out of the water.
A fish finder’s main job is to send and receive a sonar signal in the water, so without water, the transducer won’t work—all the functions of the fish finder mainly set for water only. Also, there should not be air on the transducer; otherwise, the transducer won’t send any signal.
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