How Do Fish Finders Work And How to Read a Fish Finder

The fish finder is exactly what its name suggests- a device used to find fish in the water. The ultimate tool in helping fishers find their catch for the day. It uses Sonar technology- this is determined by an echo sound reader that is sent underneath the boat to navigate where the fish is and how deep the water is. The information is then collected and quantified as data that appears on the screen of the device.

This is great for catching schools of fish. The problem starts when you have to explain the fish finder to an average person. You can lose them like you would lose a ton of fish before using this device- while trying to make them go from amateur to knowledgeable. Behind the complex science lies an ocean of tools that will drastically improve your chances. This lets the fisher know the shape and size of the target to help use the correct rod or cast to add precision to get the fish.

Lowrance fish finder

How do fish finders work and How To Read a Fish finder. Like the fish themselves, fish finders come in many shapes and sizes. The real concern is not size- but more so how to read the statistics on the fish finders screen.

The Transducer

The science behind how the transducer works is very simple. To explain it simply- it is like a bat when it is on the hunt for prey. It hovers over a certain area where it transmits ultrasonic waves to detect mostly- unsuspecting animals that are to become its meal. This is the same for the transducer in the fish sounder- It is placed right on the water or under a boat, or on a boat’ hull to locate fish much easier than done manually.

This is done by emitting waves into the ocean or river. The waves sent to the seabed are used to determine where the fish is by bringing back information about its whereabouts, the distance between the transducer and the seabed, the fishes shape and it’s size. The information is collected by using sonar technology to transmits and detect sound waves that give a clear representation between the sonar waves from the transducer and the

The transducer relies heavily upon the piezoelectric sensors to emit accurate
information. The piezoelectric feature is very stable, it neglects radio waves
and temperature to bring about accurate readings of the waves that are picked
up to appear on the screen. It can still function in temperatures of about 1000

*The electrical currents in a finder are mostly AC & DC. These are used to produce a wave cycle. When in the process, AC is converted into DC to produce the necessary electric energy that forms from the sound vibration. Crystals are formed when the echo from these
sound waves are transmitted using an echo sounder. These crystals are ideal for transforming the electric current into sound waves underwater. Exposure to electric currents is optimal in helping the piezoelectric crystals in growing and contracting

The use of alternate current in the device is so that the piezoelectric crystals produce the favorable rapid movements that cause vibrations in the water, causing sonar wave technology to bring back data about what is underlying – from the terrain, the fish, to the seaweed and other components found at the bottom of the water.

Once these sound waves return, the crystals vibrate again. The vibrations bounce back with graphic representations to reflect the findings at the bottom of the water. This returns waves to the finder that help to determine results better in the display in a visual form, this can then be interpreted by the fisherman. The crystals are overall imperative in the correct functioning of the finder-if the quality of these crystalline substances is compromised, so
will the findings collected and displayed on your screen. A fish is detected when the transmitted ultrasound wave bounces off its body- the ultrasonic wave can move in the water at a speed of a 1000 meters per second.

How to read a fish finder

Making Sense Of What Is On the Screen Display The equally integral part of the fish finder is the display screen. There have been vast improvements to the device in the current years, the screen is no longer just a black and white screen but a highly optimized and functional LCD screen that has evolved to locate fish in the water. This transformation has seen the screen updated to bring out a clear picture- improvements in picture quality and video framing have been added. Some screens can even go up to a high definition of 1080  picture quality. Fish navigators have become multi-functional.

The graphic representation is represented by a wide range of colors that show up on the screen.

1. Color and Echo Return Strength-Recent developments of the fish finder have made it easier to distinguish the details in color. The color is an indicator of the strength of the echo that is reflected back to the finder. The texture and size of an object also affect the reflected information. The depth of the color and darkness of it is used to determine the echo much better.

2. The darkest color that you find on the display is usually an indicator of the seabed of the area around the ocean. The width of a line is used to determine the depth of the water- it can either be thick, thin or in between depending on the water..This means that the surface is more of a soft-like texture- usually a clay surface. The thick line or bold line is a sign that the subject is a hard texture like a rocky surface or other thick formations.

3. Movement influences readings. When standing still- the current readings are
on the right, past reading is on the left. When in motion, the results are

4. Advanced Fish-ID systems are used to represent the fish and its depth. Fish are usually shown as icons with different shapes- mostly dots on modern systems. It is quite easy to get confused and assume that the icon is a fish-only to find that it is a rock or some other object. You should pay attention to size and dept.

The Components Of A Transducer

The most important part of the transducer is the piezoceramic component, this is responsible for converting the AC and DC electric currents. The electrical pulses are converted into ultrasonic sound waves when the frequency is initially directed at the bottom of the seabed. The sound waves are then converted into electric energy when they bounce back toward the transducer’ sound waves are that are transformed to be translated as sound waves in the LCD.

*Piezo ceramic elements are most often in a disk form, but they may also be in the shape of a bar or a ring. A transducer is made up of many parts that act together as a group to aid in its function. This group of components is referred to as an array. As complex as this transducer sounds, it is only made of six parts that give it function, They are:-

- Acoustic window
- Piezoceramic component
- The Housing component
– Encapsulating material
– Sound absorber
– The cable

How Do I spot A Fish with A fish finder?

You are probably wondering how the transducer sees a fish by now., It is enabled by detecting the organ in a fish that makes it susceptible to the sonar technology. The fish has an organ that regulates the depth in which it is swimming, this organ is the air bladder. It is responsible for the fish’ adaption to the changing pressure in water whether it is deep or shallow water-by releasing gas.

The force exerted on the fish by the water is maintained by this gas- this is what keeps the fish from the being weighed down by the water.

This is mainly because the weight of the air bladder has a different weight compared to the weight of the skeletal mass and skin density of the fish. This difference is what gives away the fish when the transducers detect the frequencies, the echo sounder is the one that picks it up the sound waves… This is then prepared to go into graphical data on the fish finder.

*The sound waves are displayed with the help of the echo sounder to present the fish, the interval between the vibration is measured in waves emitted per second. The preferred unit to measure the frequency of the waves is in Hertz.

*A Hertz is one wave movement per second in the device. 90 KHz would be about 90 000 movements per second.

Won’t the Fish Be Able to Hear Sound Waves?

They really won’t. The waves vibrate with a minimal vibration frequency- most modern transducers have a frequency that is normally in the 10 000 kHz range. Fishes inability to pick up on this makes them perfect prey for a fisher with a fishfinder in their arsenal.

The hearing capability of most species is greatly reduced underwater, fish can detect sounds that are no higher than 50 Hz on average. The ultrasonic sound waves that are produced by the echosounder are undetected in the pores that the fish uses to detect sounds called lateral lines.

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