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.
How do fish finders work
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
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
-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
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