Best Fish Finder 2020 – Unbiased Reviews & Buyers Guide

Man holding fish and rod on a boat in the water with sunset behind him

Last updated May 2020:

After extensive testing we have decided that the Deeper Smart Sonar CHIRP has out performed the Deeper Smart Sonar Pro+ to be the best castable fish finder so this list has been updated.

Want to increase your fishing haul? Here we have reviewed various products to give you the best fish finders available on the market

The invention of the fish finder is certainly a technological blessing for all anglers, giving us the ability to quickly and accurately locate the target fish, catch more fish, and turns the overall fishing experience into an enjoyable one.

To help you in researching for the best fish locator options, here we have reviewed the best models available and make our top 10 choices.

Without further ado, let’s get straight to our fish finders reviews, and here are our top 10 best fish finders for 2020 picks, in no respective order:

2020's Best Fish Finders

  • Garmin Striker Plus 4cv – Best Budget Fish Finder
  • Garmin echoMAP CHIRP 94sv Fish Finder
  • Humminbird HELIX 5 G2 Fish Finder
  • Humminbird HELIX 7 CHIRP Mega DI GPS G3 – Best Fish Finder Runner Up
  • Lowrance Hook2 5 TripleShot Fish Finder
  • Humminbird PiranhaMAX 4
  • Deep Smart Sonar CHIRP – Best Castable Fish Finder
  • Humminbird Solix 10 Mega SI+ G2
  • Raymarine Axiom 7 – Best Fish Finder Overall
  • Joylog Smart Fish Finder

Best Fish Finder 2020 Award

Comparison Table

Product Name
Overall Winner
RayMarine Axiom 7
Runner Up
Humminbird Helix 7 G3N
Best Budget Option
Garmin Striker Plus 4cv
Best Castable Option
Deeper Smart Sonar CHIRP
Raymarine Dragonfly Pro CHIRP Fish Finder with...
Humminbird 410940-1 HELIX 7 CHIRP MDI (MEGA Down...
Garmin Striker Plus 4cv, 4.3" GPS Fishfinder with...
Deeper Chirp Smart Sonar Phone Castable Wireless...
Screen Size
7” wide screen
7” wide screen
4.3” vertical screen
none (smartphone connectivity)
RealVision 3D, downcan, sidescan, dual spectrum CHIRP
Sidescan, downscan, dual spectrum CHIRP
CHIRP, ClearVu (downscan), dual chirp
3 Frequency CHIRP
Overall Winner
Product Name
RayMarine Axiom 7
Raymarine Dragonfly Pro CHIRP Fish Finder with...
Screen Size
7” wide screen
RealVision 3D, downcan, sidescan, dual spectrum CHIRP
Runner Up
Product Name
Humminbird Helix 7 G3N
Humminbird 410940-1 HELIX 7 CHIRP MDI (MEGA Down...
Screen Size
7” wide screen
Sidescan, downscan, dual spectrum CHIRP
Best Budget Option
Product Name
Garmin Striker Plus 4cv
Garmin Striker Plus 4cv, 4.3" GPS Fishfinder with...
Screen Size
4.3” vertical screen
CHIRP, ClearVu (downscan), dual chirp
Best Castable Option
Product Name
Deeper Smart Sonar CHIRP
Deeper Chirp Smart Sonar Phone Castable Wireless...
Screen Size
none (smartphone connectivity)
3 Frequency CHIRP

Fish Finder Reviews

1. Garmin Striker Plus 4cv - Best Budget Fish Finder

Garmin-striker-plus-4cv product image

Small and portable from big name!

Coming from Garmin, one of the pioneers and biggest names in GPS technology, the Striker Plus is their latest iteration for their flagship fishfinder brand featuring built-in GPS and CHIRP sonar capabilities. 

The 4 in the name stands for the screen size, 4.3” with 272x480 pixels screen resolution. The CV stands for ClearVü, Garmin’s signature down scanning method with very-high frequency (260/455/800 kHz) scanning to provide very clear, nearly photographic image below your vessel.

While they are quite small, the garmin fish finders have a 4.3” display that can provide various screen modes to fully utilize both GPS and sonar features.

The transducer can operate in three different modes/frequencies: Traditional (50/77/200 kHz), CHIRP, and ClearVü, giving you a tremendous versatility to suit your different needs. 

Key Highlights

Portable and Powerful

Portable 4.3” high-resolution screen but offers great features. 

ClearVü Down Scanning Feature

Great down scanning feature offering very high frequency (260/455/800 kHz) scanning for more details.

3-in-1 Transducer

Offering traditional dual-beam, CHIRP, and ClearVü in just one transducer for more versatility.


  • Three different transducer frequencies: traditional, CHIRP, and ClearVü, very versatile
  • IPX7 water-resistant
  • 300 wattage power for optimal image quality
  • Split-screen zoom
  • A-scope feature, real time display of passing fish
  • Ultrascroll feature to display target fish at higher boat speeds
  • Portable, battery-powered display unit
  • Garmin quickdraw contour mapping software to easily create and store maps
  • GPS built in


  • No cover included with purchase
  • No NMEA port


A relatively affordable, portable fish finder with excellent set of features. The best choice if you want a portable system. 

2. Garmin echoMAP CHIRP 94sv Fish Finder

Chartplotter fish finder from Garmin

Another one from Garmin, but from the echoMAP product line, which is Garmin’s brand for chartplotter-fish finder combo, so we can expect more GPS and charting features compared to the Garmin Striker series.

The EchoMax 94sv offers a 9” WVGA screen with 800x480 resolution, ensuring a sharp, crisp display with a large screen.

garmin echomap chirp 94sv product image

Being a chartplotter, the EchoMAP 94sv is preloaded with Bluechart G2 mapping chart, covering the coastal US with 5,000 waypoints, and you can add your own maps via microSD.

For the finder functionality, the EchoMAP 94sv offers a transducer capable of CHIRP, ClearVü, SideVü—Garmin’s advanced side imaging feature—. So, you get very clear imaging of what’s below and to the sides of your vessel.

Key Highlights

Big 9” High Resolution Screen

If you want bigger screen that can display advanced charting and fish finding information, this is for you.

3-In-1 Transducer: Dual-Beam CHIRP, ClearVü,SideVü

Very versatile with 3 different scanning methods, high-quality down imaging and side imaging 

Advanced Chartplotter features

Supports AIS, DSC, and ActiveCaptain-compatible. Preloaded Bluechart G2 charting.


  •  High resolution (800x480) 9” WVGA screen
  • Advanced charting features
  • Internal 5Hz GPS
  • Easy mounting, the cable ports are included on the mount
  • Impressive 3-in-1 sonar functionalities


  • Relatively expensive
  • LakeVu lake mapping sold separately


Great if you want a big screen and want the advanced chartplotting GPS features.

3. Humminbird HELIX 5 G2 Fish Finder

Beautiful widescreen display

Humminbird is certainly one of the biggest names in fishing industry, and the Helix 5 is it’s more affordable entry, with the high-end Humminbird Solix starts from $2,000.

However, even the Helix 5, that costs just a tenth of that, offers a really nice set of features from the CHIRP digital sonar, 5” high-resolution (800x400 pixels) display, SwitchFire sonar for more versatility, and more. 

Humminbird HELIX 5 CHIRP SI GPS G2 Fish Finder product image

Also, comes with a built-in GPS, allowing features like AutoChard Live—creating real-time maps of your prime fishing spots— access to Humminbird LakeMaster maps database, and integration with Navionics (more maps!).

Key Highlights

500 Watt Power

Very powerful for its size and price, ensuring optimal sensitivity and clarity at all times.

5-Inch Color WVGA Display

Very beautiful display that is optimal even on bright sun conditions, and still offers a portable size.

CHIRP DualBeam Plus

Latest, most sophisticated sonar technology. Ensuring very sharp and clear images from the bottom of your vessel. 


  •  Integrated GPS
  • 500W power
  • Optimal for as deep as 2500 feet
  • Supports 50/83/200/455/800 kHz, very versatile
  • High quality 5” screen
  • Mount included, very easy to install
  • NMEA support


  • Not battery operated
  • Relatively expensive compared to Garmin Striker 4 CV


Affordable option from Humminbird, ensuring reliability and quality. Very beautiful wide-screen 5” screen with great set of features. 

4. Humminbird HELIX 7 CHIRP Mega DI GPS G3 - Best Fish Finder Runner Up

Humminbird HELIX 7 CHIRP Mega DI GPS G3 product image

Bigger and better

Another one from Humminbird, and as the name suggests, Helix 7 features a 7” widescreen TFT display with 800x480 resolution.

This is also the newest model from Humminbird (3rd generation), while the Helix 5 we’ve discussed above is from the 2nd generation. As a result, this is significantly more expensive, but also offers some new technologies and features.

For instance, the Helix 7 Gen 3 features both side imaging and down imaging with CHIRP sonar. Also, there are two modes of CHIRP: wide mode for maximum coverage on shallow waters, and narrow mode for more clarity and depth. In short, a very versatile unit.

Key Highlights

Mega Side Imaging

Crystal-clear viewing of up to 125 feet from either side of your vessel.

Mega Down Imaging

Extreme clarity of up to 125 feet below your boat.

Dual Spectrum CHIRP

Can utilize CHIRP both in narrow cone and wide cone for maximum versatility.


  •  Very versatile with down imaging, side imaging, and two modes of CHIRP
  • Impressive 7” wide screen with high resolution display
  • MicroSD slot for extra memory
  • Integrated GPS, compatibility with Navionics and LakeMaster
  • Mounting hardware included
  • Can reach up to 1,500 feet in depth
  • Ethernet networking available to access various technologies from Humminbird


  • Expensive
  • No Wi-Fi connectivity


Great option if you are willing to spend more for quality, definitely worth the money.

5. Lowrance Hook2 5 TripleShot Fish Finder

Lowrance Hook2 5 TripleShot product image

Versatile and easy to use

Lowrance is also a very big name in the world of marine fishing and especially fish finders, and the Hook2 5 offers several unique features compared to its competitors.

One of the biggest highlights of Lowrence products is its ease of use, the transducer can be mounted in a variety of different ways, and Hook2 display’s user interface is very intuitive.

The transducer included is named TripleShot for its 3-in-1 sonar capabilities: downscan, sidescan, and CHIRP. The Hook2 CHIRP is also special, offering a very wide sonar angle, doubling the cone angle of its competitors.

Key Highlight

TripleShot Transducer

Capable of DownScan (down imaging), SideScan (side imaging) and very wide CHIRP.

Preloaded High-Detail US Inland Maps

Including 4,000 lakes with 1-foot contour. 

Easy Setup and Intuitive

Very intuitive user interface for easy setup, versatile transducer that can be transom or through-hull mounted.


  • Relatively affordable for its features
  • High resolution SolarMax 5” display
  • Autotuning sonar, with wide cone CHIRP
  • Down imaging and side imaging capabilities
  • Great GPS integration with built-in mapping


  • Cover sold separately
  • Can’t view down imaging in split-screen


This option offers ease of use over all the rest as it has many functions that are easy to use and a great buy for intuitive anglers.

6. Humminbird PiranhaMAX 4

Affordable option from Humminbird

PiranhaMAX is the entry-level line from Humminbird, featuring a smaller 4.3” screen. As an affordable option, comparison to Garmin Striker 4 is unavoidable, and there are several key differences between the two. 

First, the PiranhaMax4 display is slightly bigger at 4.3” opposed to Striker 4’s 3.5”, but the screen resolution is slightly lower at only’ 272x480 pixels. 

Humminbird PiranhaMAX 4 product image

Only supports 200 and 455khz (dual-beam), and effective up to 600 feet. 

Key Highlights


Slightly more affordable than Garmin Striker 4 with a bigger screen.


Doesn’t offer advanced technologies and features, but very reliable with at traditional dual-band sonar


  • Very affordable, the cheapest on this list
  • Decent dual-band transducer than can cover up to 60 feet in depth
  • Easy to use keypad interface


  • No CHIRP technology
  • Down imaging transducer sold separately
  • No GPS


The most affordable on this list, but in most cases, Garmin Striker 4 is better. 

7. Deep Smart Sonar CHIRP - Best Castable Fish Finder

Deeper Sonar CHIRP packaging and product

Affordable wireless castable fish finder

Deeper is a relatively smaller name compared to Garmin, Lowrence and Humminbird, but the Smart Sonar CHIRP is an updated product offering several features.

The Smart Sonar Chirp, for instance, is a wireless fish finder. So, you don’t get a display unit here, but the floating transducer can connect with your smartphone over a wireless connection.

For a castable fish finder, the transducer is great with 3 Frequency CHIRP -     Narrow CHIRP 675 kHz (cone angle 7°),
Medium CHIRP 290 kHz (cone angle 16°),
Wide CHIRP 100 kHz (cone angle 47°).
This will allow accurate scanning for up to 330 feet in depth.

Key Highlights

Castable Wireless

Connect to your smartphone via Wi-Fi connection for up to 330 feet (100 meters)

3 Operating Modes

Standard, Ice fishing, Boat

15 Scans Per Second

Accurate reading with 15 scans per second and variable target separation


  • Relatively affordable
  • Wireless castaway design, perfect for land-based fishing, kayak, and ice fishing
  • Compatible with iOS and Android devices
  • Long battery life, can last 6 hours of continuous usage
  • 3 Frequency CHIRP
  • Quick charging time (75 minutes)


  • No Built-in GPS
  • No dedicated display unit


Excellent option if you are looking for a wireless castaway fish finder.

8. Humminbird Solix 10 Mega SI+ G2

Humminbird Solix 10 Mega SI+ G2 product image

Top of the line Humminbird

Solix is Humminbird’s line of premium fish finders, andthe Solix 10 features a 10.1” 1280x800 HD multitouch screen, giving you a premium, very high-quality display.

Solis 10 also offers MEGA down imaging+ and MEGA side imaging +, 20 % improvements over already excellent imaging from the Helix series, and that’s saying a lot. 

Also, the transducer can cover a wide range of frequencies from 28kHz up to 800kHz. A premium product with state-of-the-art features.

Key Highlights

MEGA Down Imaging+ and MEGA Side Imaging+

Clear, lifelike images from up to 200 feet below your vessel and 200 ft from either side of your vessel

High-Quality 10.1” Display

Very high resolution 1280x800 pixels 10.1” display with cross-touch and multi-touch functionalities.

Wide Frequency Range

Full Mode (28-75 kHz), Narrow Mode (75-155 kHz), Optional Deepwater (28-250 kHz), Wide Mode (130-250 kHz


  • Very high-quality 10.1” display with 1280x800 pixels resolution
  • MEGA Down imaging+ and Side Imaging+, 20% improvements over standard Humminbird imaging
  • Excellent transducer with dual-spectrum chirp
  • Can reach 1200 feet in depth


  • Expensive premium product


Excellent premium option if you want more clarity in downscan and sidescan functions.

9. Raymarine Axiom 7 - Best Fish Finder Overall

Raymarine Axiom 7 product image

The main highlight of the Raymarine Axiom 7 is the inclusion of Raymarine’s RealVision 3D sonar feature, giving you a very accurate, 3D presentation of what’s below your vessel. 

The transducer also offers traditional CHIRP, down imaging, and side imaging besides the RealVision 3D sonar, giving you utmost versatility and accuracy.

Very powerful 7” display unit with quad-core processor and Raymarine’s very intuitive Lighthouse 3 OS.

Key Highlights

Realvision 3D

See what’s below your boat in lifelike 3D presentation.

Powerful Display Unit

High-resolution display with quad core processor and Lighthouse 3 user-friendly OS.

CHIRP, DownVision, SideVision, RealVision 3D

4-in-1, versatile and powerful transducer for just about any applications.


  • 4-in-1 transducer with RealVision 3D, traditional CHIRP, CHIRP sidevision and CHIRP downvision
  • Quad-core processor, fast and smooth real-time performance
  • Multi-touch, 7” high resolution screen
  • Lighthouse 3 OS
  • Connectivity with your smartphone (iOS and Android)


  • Expensive 
  • Screen can glare during direct sunlight


Great high-end option, the RealVision 3D sonar is a major treat.

10. Joylog Smart Fish Finder

Very affordable castaway fish finder

Another wireless, castaway fish finder to directly compete with Deeper Smart Sonar PRO+.

For starters, it is more affordable than Smart Sonar PRO+, so it can be a major consideration if you are looking for a castaway finder on a budget.

joylog Smart Fish Finder

Very light at just 0.51 lbs, and can detect as deep as 131 feet. 

Comes with an easy to use, iOS and Android app, but the overall features are pretty basic with just a single beam transducer.

Key Highlights

Affordable Castaway Option

Very affordable, with very decent features.

Lightweight and Portable

Very lightweight at just 0.51 lbs and only 2.6 inch in diameter, a great portable option and a reliable back-up if you have an existing fish finder.


  • Affordable
  • Lightweight and small diameter, very portable
  • Can communicate with your smartphone for up to 164 feet in range
  • 131 feet maximum detection


  • Limited battery power 
  • Single cone, with only 30 degree detection angle


The greatest aspects of the Joylog are its affordability and portability. A great option for beginners or as a back-up.

How A Fish Finder Operates

A fish finder, as the name implies, has just one core feature to locate the fish automatically, enhancing your fishing experience by allowing you to catch more fish.

They typically consists of two different parts: the display screen and the transducer. Due to its relatively simple configuration, fish finders are in most cases, very easy to use even for absolute beginners. 

The display screen—or display unit—can be mounted onto the boat or can be a portable unit you carry around. The purpose of the display unit is fairly obvious: to display the information you need.

For instance, it will display how far down the fish is located, where it is located, and how deep the water below you is. 

The second part of a fish finder is a transducer, with two main functionalities: emits high-frequency sound wave by converting electrical energy into sound energy, and receives back the reflection of the sound wave before converting it back into electrical data. The transducer operates using a sonar technique to propagate the location of the fish (and the bottom of the water), and deliver the data to the display unit. 

As you can see, the process is relatively simple. So, not only it is relatively easy to use, the simplicity will also minimize the risks of technical issues. 

A fish finder is ideal for any fishers using any kinds of boats, large or small. Also, it is useful to get a better insight of the surrounding water, so it can be useful, for example, for kayaking so you can easily know when you are nearing any logs or rocks.

Different Types of Fish Finders

Although there are many different fish finder products available on the market, we can generally divide them into three types based on its functions.

You can choose between these three types according to your fishing style and needs:

Mountable Fish Finder

This type consists of mountable transducer and display unit. Depending on their mounting types (will be discussed below), the fish finder might be attached temporarily or permanently to the boat. This is a great choice if you are an angler that owns your own boat or can rent the same boat regularly.


Portable (Handheld) Fish Finder

With this type, you get a small display unit (4” or below) and a portable transducer with temporary mounts. Typically this type operates on (rechargeable) battery. Great choice if you rent your boats.

Wireless Fish Finder

FishHunter Directional 3D Fishfinder

A relatively new type of fish finder, consisting of a floating, wireless transducer that can transmit data to your smartphone via mobile data or wifi. Popular with land-based fishers.Enter your text here...

What Is a Good Price For a Fish Finder?

Answering this question can be fairly difficult since there are a lot of factors that should be considered, depending on your needs, fishing style, location of your fishing spots, and so on.

Fish finders can be as affordable as under $200, while truly high-end models can cost above $1,000.

First, consider the location of your fishing spot and what type of fish you are going to catch. Based on those, consult our Important Considerations section below and determine what features you will need for your purpose. In most cases, you’d want to look for the most affordable model that offers all (at least most) the features you need.

In general, however, expect to spend at least $300 and under $500 for a decent fish finder. You can certainly opt for more expensive products according to your budget, but spending above $1,000 is usually overkill. So, your ideal range should be between $300 and $1,000 to get the best fishfinder for you.

Important Considerations When Choosing a Fish Finder


Transducer is an essential element of any fish finder, and in a nutshell, is an electrical device that converts energy from one form to another.

A microphone—converting our voice into electrical energy—, is technically a transducer. In the case of fish finders, the transducer converts electrical energy into sonar waves, and vice versa.

The transducer emits sound waves and receives the returning echoes, this is the principle of sonar for locating objects underwater. The transducer will then send the converted data to the central display unit so we can read the data.

As this is the core functionality of a fish finder, we can see how a transducer is really important.

There are three main factors when considering a transducer: mount type (which will also dictate material), cone angle, and frequency.

Transducer Mount Type

Note: there are two different elements of a finder that requires mounting: the display unit (called binnacle mount) and the transduce. Here we are specifically discussing the transducer mount.

There are several types of transducer mounts available:

Transom Mount

The most common type, and generally the most affordable, this mount is mounted on the transom—hence the name—.

Transom mount is typically the most affordable type, and commonly made of plastic. As a result, it is less durable than other types.

It is very versatile and can work in almost all situations, especially in smaller boats.

Yet, it is not advised to use them with larger boats over 30-feet in length, and boats moving at an exceptionally high speed—due to the lower quality of the build—.

Another important consideration is that a transom mount is not a permanent attachment, so you can, for example, attach it to a small boat or kayak temporarily.

Through-Hull Mount

Through-hull mounted transducers are generally much sturdier, and thus are more reliable at higher speeds. The strongest, most durable mount type, but also usually the most expensive.

Fish finders that utilize through-hull mounted transducers are generally designed for high-speed boats and long-range fish detections.

In-Hull Mount

This type is the easiest to install since you wouldn’t need to drill an additional hole to place the transducer. However, this type requires specific types of hull material that can be penetrated by sonar waves. This is why the transducers using this mount is often called “shoot-through” transducers.

Also, when picking out a through-hull or in-hull transducer, it’s important to choose the right material based on your hull material:

  • Fiberglass or wood hulls will typically need bronze mounting/housing
  • Aluminum or steel hulls need stainless-steel mounting
  • Fiberglass or plastic hulls can work with plastic mounting

Transducer Cone Angle

Cone angle refers to the width of the sound wave emitted into the water for your boat, for sonar detection purpose.

The wider the cone, the larger the area that is covered. It’s important to understand that the deeper the sound wave goes down, the lower the intensity projected back to the transducer—so, less accuracy and can produce image distortions—.

The wider the cone at a lower depth, the better if you want to fish in shallow waters. However, if you want to fish commercially in deep waters, you will need a transducer with narrow cone angle but high frequency (more on frequency later).


Transducers can come with cone angles ranging from a mere 9 degrees to more than 60 degrees. However, most fish finders tend to offer a cone angle between 16 and 20 degrees. A 20 degree cone angle is a decent choice for most fishing needs.

Some also offers multiple beams. Dual and triple beams transducers will cover more areas in lower depth, so it’s a better choice if you fish in shallow water. However, they can be significantly more expensive.

Transducer Frequency

Frequency here refers to the frequency of the sound wave emitted by the transducer. The higher the frequency, the wider the cone angle. However, higher frequency will produce a shorter soundwave, so it won’t be able to reach deep areas.

Transducers usually come in 50, 83, 192, or 200 kHz sound frequencies, although some really high-end fish finders can reach 400 kHz or more.

In general, if you want to fish in mainly shallow waters, higher frequencies (192 or 200 kHz) are better, but lower frequencies (50 kHz) are better for deep waters.

Some units can switch back and forth between high and low frequencies, so this might be your best bet if you are looking for versatility.

Also, there are models that operate on both types of frequencies (dual-frequency) and even multiple frequencies. Typically these models with dual or multiple frequencies will also involve a larger display unit so you can view readings from each frequency in a split-screen.

CHIRP Sonar and CHIRP Transducers

CHIRP, stands for Compressed High-Intensity Radiated Pulse, is the latest, most sophisticated sonar technology available today.

Standard sonar sends 1 frequency at a time. So, if you want two different frequencies, you will need two different transducers.

CHIRP sonar, on the other hand, emits sweeping frequencies from low to high continuously, and the transducer with CHIRP scanning capability will then interpret the different reflected frequencies individually. As a result, CHIRP sonar produces a much clearer image with a higher resolution.

Newer models offer CHIRP sonar capabilities. While they are relatively expensive, know that you’re in for a treat with a CHIRP transducer.

Display Unit

If the transducer is about how well the fish finder unit can locate the fishes, the display unit is about how well it can show you the information—the user experience—.

In many cases, how we choose a display is similar to choosing an underwater fishing camera, although it’s also important to consider some technical factors like how well it presents the data (i.e. with colorful charts, easy to read graphics, etc.).

Here are some important factors when considering a display:

Monochrome VS Color

Pretty self-explanatory. Colored screens are the standard nowadays, but the old-school black and white screens are still a viable option in more affordable models.

Monochrome screens, however, are harder to read in dark or cloudy conditions.

Screen Resolution

Screen resolution ultimately refers to how many pixels a screen will display. The more pixels, the more details and the smoother you’ll see the displayed images.

You should, at the bare minimum, look for at least 240x160 pixels resolution (keep in mind, this is fairly low-res). In newer models—including the ones we have reviewed above—, higher resolutions or even HD resolutions are quite common and affordable.


Different models come in various screen sizes from around 4” to 9” screens. The larger the screen, the more expensive.

Also, remember that it’s harder (and more expensive) to maintain high screen resolution with a larger screen. If you are planning to get a bigger screen (7” or above), pay extra attention to the screen’s resolution to ensure you’ll get the desired clarity and details.


The wattage of the fish finder unit will determine speed and depth.

The higher the wattage, the faster the projected soundwave will move, and the deeper it can penetrate water.

The frequency of the soundwave will also affects power usage, for example:

  • With a frequency of 50kHz and 100 watts of power, you can reach up to 400 feet in depth.
  • With a similar power of 100 watts, yet 240kHz of frequency, we can only each 100 feet of depth.

So, in general, if you fish in mainly shallow waters, you won’t need a high wattage, but you can opt for higher frequency.

Scanning/Imaging Methods

There are two different scanning, or imaging modes performed by different fish finders: downscan (or down imaging) and sidescan (side imaging).

Side imaging sonar works by using two beams—positioned on each side of your vessel— pointed slightly upwards.

A side imaging fish finder allows us to scan a wider area of water and to see schools in great detail as we pass. However, the downside of side scan sonar is that it won’t produce effective imaging in deep waters, as it won’t cover too much area below your boat.

This is where a down imaging sonar comes in.

Down imaging sonar utilizes a single transducer that emits a thin, but powerful sound wave directly below your boat. Thus, a downscan fish finder is usually the better bet for monitoring bait schools in deep water.

Down imaging can offer very detailed view of what’s beneath your boat, and so is generally a better choice if you like stationary fishing.

Side imaging, on the other hand, is better when you are scanning for shallow diving fish.

Portable VS Mounted

Portable models are generally more affordable—due to their smaller size—, and so they are often portrayed as just that, an affordable alternative to a “real”, bigger, mounted fish finder.

However, it can’t be further from the truth. There are portable fish finders that offer really advanced transducers and really high screen resolutions, and on the other hand, there are many affordable mounted/fixed models with large screens.

It’s true, however, that in general a portable fish finder that is comparable (in price) to a fixed fish finder will offer less overall quality.

So, when comparing the two, it’s best to focus on the main issue that is portability. If you, for example, rent different boats all the time, prefer smaller boats, or wanted to use the fish finder for kayaking, then a portable finder is a better choice.

On the other hand, if you want more advanced technology for the same budget, a fixed/mounted finder is a better bet. Fixed models are also usually more stable and reliable, so it’s a better choice for boats with higher speeds. Also, they are generally more consistent and you wouldn’t need to re-tweak the settings all the time.

GPS Integration

We are all familiar with the GPS technology nowadays, and many models also offer GPS/Chartplotter feature, which can provide various benefits:

  • Navionics and Charting: GPS can provide an easier time to navigate your way to prime fishing grounds or to find your way back to dry land. Some of the GPS fish models offer the ability to customize your charts, which can be useful so you can navigate to the right fishing spot every time.
  • Water Temperature: You might encounter fishing spots where cold and warm waters meet, and a GPS feature will help you navigate between water temperatures. You can, for example, track your next catch based on whether it's a cold water or warm water species.
  • Location Saving: You can save different locations like different prime fishing spots, dangerous areas, and so on. So you can navigate to these locations accurately.
  • Depth Finder: GPS models offer both mapping and charting features, so you can get a more accurate reading of the land in a way that isn’t possible with a standard fish finder. You can get a better insight about the bottom of the water, and can easily decipher the depth readings.

Even if you’ve already familiar with a standard fish finder, using a GPS—or Chartplotter—fish finder will be a little bit different. Here are some tips you can use to make the most of your GPS feature:

  1. Buoys: Buoys are used to mark different water depths and shipping lanes on water. A GPS feature can help you track the position of these buoys without needing to plot them by yourself.
  2. Contour Lines: These lines are designed to show you the topography below the water. Knowing the accurate position of hills and valleys beneath your vessels can be beneficial, since certain fish tend to swim only in specific depths. This can result in significant increase of your haul.
  3. Shipwrecks: Some GPS units can effectively highlight shipwrecks locations on the map. This can be useful since fish tend to swim around shipwrecks, and can also protect your boat from potential dangers when exploring around.
  4. Seabed: Some fish species tend to hang out at specific depths, and a GPS tracking will offer a more accurate reading of the seabed’s layout. This will provide you with a better chance to increase your haul by offering a more optimal positioning.

Water Resistance

If you are going to use the fish finder on an open vessel, then water resistance is going to be an important factor.

Check JIS or IPX ratings, which are usually listed on the product’s specifications. An IPX rating of 4 (IPX4) means the device is fairly safe from splashing water, but it won’t be sufficient if, for example, you are on a kayak.

An IPX rating of IPX5 or IPX6 means the finder can resist fairly high pressure of water jets, and IPX7 will mean you can safely submerge the unit up to 10 feet deep of water, for as long as 30 minutes.

Lastly, IPX8-rated products can stay underwater for an extended period of time.

Best Practices In Using Your Fish Finder

So, you just got your brand new fish finder and you can’t wait to try it out on your fishing trip.

It’s certainly good to be excited, but don’t forget that it’s important to prepare ahead so you can make the most of your new tool (toy).

Below, is a step-by-step guide for the best practices in setting up and using your fish finder.

1. Read The User’s Manual

Yes, not all of us like to read, but it’s a necessary step. Keep in mind that today’s user manuals are generally not that long and will only be a few minutes of reading.

Familiarize yourself with how to set up and program the fish finder, how to mount it, and how to read the data. If necessary, you can also search online for forums, communities and reviews for more clarity about certain issues.

2. Mounting The Fish Finder

Again, refer to the user’s manual on the recommended placement to mount the finder—and how to mount it—. Different fish finders might require different mounting process and placement.

Also, depending on the model, you might also need to mount the display unit beside the transducer. Refer to our transducer mount section below for more information

3. Setting Up The Fish Finder

When you turn on the fish finder, all models will start with the automatic mode, operating on pre-programmed settings. If you want, you can switch it to the manual mode to customize the finder according to your preferences and needs.

However, it’s better to leave it on automatic mode first and “test-drive” the system on the water to get the basic idea of the visual data presentation, clarity of the detection, whether it’s mounted properly, etc. Make your adjustments after you’ve got a grasp of its behaviour.

4. Make The Necessary Adjustments

The automatic mode, in essence, is allowing the sonar unit to automatically set the sensitivity (power output). It might or might not be effective according to your preferences, and this is how a manual adjustment can help you.

Here are the steps you can follow to make a proper manual adjustment:

  • Bring your boat to a depth above 20 feet. It is best not to make manual adjustments in shallow water, since the cone angle will be smaller in lower depths. If you commonly fish in deep water, bring your boat to a depth you commonly fish in.
  • Turn of the auto-sensitivity feature, switch to manual mode, depending on your model. Make sure all automatic features are off, including fish ID if the finder has the feature.
  • Now, manually adjust the range of the fish finder to more than twice the actual depth. For example, if you are in 30 feet of water, adjust the range to 65 or 70 feet (60 feet will not work). If the model allows, you can set the depth to three times or more, it will work just as well.
  • Adjust gain or sensitivity until you can only see a faint echo from twice your actual depth. For example if your depth is 30ft, you will see this echo at 60ft. This is called the second echo, that when present, indicates that optimal echo signal is received by the transducer. If your sensitivity is too high, this signal will be distorted. Make your adjustment until you get this second echo.
  • Re-adjust the range to the actual depth, or you can turn on the auto-range/auto depth feature. In general, avoid using auto-sensitivity feature (unless it’s an advanced model with really good auto-sensitivity feature) and fish ID (we will discuss more about fish ID below).

The following factors can affect the sonar’s sensitivity:

  1. Water depth
  2. Water temperature and density
  3. Clarity
  4. Salinity
  5. Boat speed: less sensitivity is required when the boat is moving at a slower speed.

5. Fish ID Setting

The Fish ID feature will allow us to identify fish automatically, which is ideal if this is your first fish finder or a complete fishing beginner, or when you are just figuring out a brand new finder.

However, after you’ve adjusted to the fish finder’s display interface, it is better to turn it off. By turning the fish ID off, you can get a better view of what’s actually going on underneath the waves.

6. Using Auto Range/Auto Depth

The auto depth feature, as the name suggests, will automatically track the depth of the water, so you can get an accurate information of how far down it is. In most cases, it’s best to leave the auto range feature on, but you can make some adjustments.

For example, you can hide the first few feet and just above the true bottom. This can be useful if you know the fish is not on these depths, and so the sonar can set its sight on the depth that matters.

7. Reading Depth Cursor

The depth cursor is a line that goes across the display screen, and will provide information on how far down the fish actually is. This will provide you with an easier time to determine where to put your bait, and how deep. The depth cursor will constantly move up and down the fish, according to the fish’s current position.

8. Adjusting Suppressor Setting

Generally, you don’t want to keep the suppressor on at all times, since it can block the sonar sound waves.

Suppressor, however, can be useful to block out the background noises when your boat is moving at a relatively high speed.

If your transducer is installed correctly, usually the suppressor setting will be automatic and will perform correctly. However, you can make manual adjustments when necessary.

FAQ's About Fish Finders

What is a fish finder?

What Is GPS Feature In a Fish Finder?

What Are The Different Types of Fish Finders?

How Do I Read The Fish Finder?

What Frequency Are Common For Fish Finders?

Are Fish Finders Waterproof?

How Can I Install The Fish Finder?

Can We Use Fish Finder on a Kayak?

What Is The Best Brand To Choose?


A fish finder is a fisherman’s best friend, an affordable solution to improve your haul.

While there are many different types and sets of features available, the best way to make your choice is to first figure out your needs: your fishing style, your fishing location, and ultimately, your budget.

In this best fish finder article the products we have reviewed above, as well as the buying guide, should help you in making a better informed decision to purchase the perfect fish finder for you.

Last update on 2020-05-29 / Affiliate links / Images from Amazon Product Advertising API

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James Williams

I love to write for readers with a genuine interest in enjoying the fishing. Hence, I started this blog to provide you guides so that you can have a better and more pleasant fishing experience.

Click Here to Leave a Comment Below 3 comments
Phillip Rogerz - November 4, 2017

Fishing has become a important part to pass our leisure. I love fishing, when I got time then fishing makes me crazy to enjoy a wonderful time. Wish to read it before to buy a fish finder.

john bass - April 17, 2018

it is a very nice review article about the fish finders … thanks

Morris Jones - September 22, 2019

This information was very good for someone trying to decide which is best for my needs. I love to fish but I REALLY love to catch. The thing that resonated with me most were the reviews of some problems that some folks had with customer service and the lack of it. I am really leery of Hummingbird now. Not feeling good about Garmin but not as much. The greatest thing I look for in any purchase is customer service and product support. THAT gets my money. Thank You very much for you article.


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