Our Ultimate Fish Finders Buyers Guide In Details

As technology evolves, the fishing sport continues to get much easier and fun for even the most amateur angler. Fish finders continue to get more sophisticated and this allows for more detailed imaging and more precise accuracy.

The advancement in technology also brings about a wide variety of features including GPS, flashers, custom mapping, and temperature probes.

Different fish finders will give you different types of images, so you want to ensure that you choose the right fish finder to satisfy your unique fishing style.

Now, the problem is that, even after reading different portable fish finder reviews out there, you might still feel lost in all the technological talk. With all the different features and functions that come with this equipment, selecting the right product can be a daunting task, especially to first-time buyers. Between different types of transducers, sonars, flashers, echoes, and other things, it’s difficult to make sense of everything.

Not to despair though, as we have put together this comprehensive fish finder buyer’s guide detailing everything you need to know before buying a fish finder. That way, you’ll be confident that you are buying the right equipment for your needs.

garmin fishfinder

But first:

What Exactly is a Fish Finder?

This is a sonar device designed specifically to help detect fish under water. A fish finder works by detecting mirrored signals of electric sounds. All the electronic signals mirrored of the fish are transferred into selective information and then revealed in graphic presentation on the fish finder’s display screen.

Other than locating fish, these devices additionally help you to calculate the extent of the water, locate underwater debris and also know what is at the bottom of the water. The graphics found on the screen of this equipment is able to depict one specific fish in form of a small symbol.

How does a Fish Finder Work?

Knowing how this equipment functions will help you know the best way on how to use a fish finder. Now, fish finders function by using sonar (Sound Navigation and Ranging). This is a technology that uses sound waves to display underwater constituents.

The fish finder produces the sound wave using the transducer and then transfers it through the water.  Plunging deeper through the water, the sound wave starts to disintegrate in the form of a cone (beacon). And, as the wave adjoins the object (which is the bean in this case), it heads the indicator back to the transducer again.

Basically, sonar utilizes sound to detect objects underwater. The active sonar in fish finders transmits sound vibrations into the water and awaits an echo. It then portrays a picture of whatever the sound sprung off of, for instance, a swarm of fish. Frequencies may range from infrasonic, meaning very low, to ultrasonic, meaning very high.

Fish finders come with two major types of sonar: side scan and down scan. There is however, a new technology that combines both.

Since sonar transmissions are shown on the screen, a fish finder scans and allows you to see the bottom surface and any other little thing it encounters along the way.

The sonar beam’s viewpoint is called the cone angle and it is calculated in degrees. A broader angle means more area under water. A number of fish finder brands incorporate different cone angles. Some brands also include multi-beam sonar technology that screens a significantly wider area.

How to Read a Fish Finder

Different fish finders have different unique features. There are those with screens to display the indicator from the transducer. Others can communicate with your iOS and Android devices via Bluetooth or Wi-Fi. However, knowing how your fish finder works is the appropriate action to understanding how to read it.

Here are a few steps to reading a fish finder.

Identifying Fish

To increase your chances of catching fish, you need to be able to identify it. The fish finder screen is a friendly interface that makes it possible to see what’s beneath the boat.

Fish Icons

A fish finder has a fish-ID that allows you to locate the fish icons. Since the icons come in different lengths and shapes, it’s easier to distinguish a fish from a rock or plant. You’ll be required to verify the icon on the display, and its depth.

Fishfinder dispaly

Fish Arches

Most fish finders tend to display the indicators from the transducer in form of lines and arches. As you will notice, images in the shape of arches are much clearer and easy to read compared to fish IDs. For instance, a big arch displayed on the screen means there is a large fish below, while a small fish arch represents a small fish.

Sometimes you may experience difficulty trying to discern a rock from a fish. Don’t worry, keep trying until you master the art.

Analyzing Fish Size

We’ve said above that the size displayed on the screen is actually the same size of fish beneath. But, that’s not always the case. You’ll have to make further scanning of the displayed arches.  You’ll do this by checking the thickness, length, and width of the arch.

Fish arch length

It’s important to note that a long fish arch doesn’t necessarily mean a big fish. Thus, the length of the arch should be measured as time; meaning whatever you see on the display is proportional with your location to the fishes. For instance, if your fish finder meets a motionless fish, you’ll possibly see a continuous line. The fish in this case could either be small or big.

If your transducer takes in two fishes underneath, which are moving at different speeds, the fish with the slowest speed bear a long line while the one moving fast will have a short line. The size of the fishes does not apply here; meaning the long fish arch doesn’t really mean big fish.

The fish arch width

As seen from the above discussion, the arch length doesn’t show the size of the fish, but, what about the width of the arch? When analyzing a fish finder screen, it’s advisable to always consider the vertical rather than the horizontal. Regardless of the length, a thick arch means a big fish

Full or half fish arches

Your screen will either display full or half arches. Full arch will show when the fish is in the cone section of the sonar. Also, a half arch will display when the fish swims to a particular section of the cone.

Here, the arch being half or full has nothing to do with the size of the fish. As mentioned earlier, the best way to tell the size of the fish is to check the width of the arch.

How to Find Trophy or Bait Fish on your Fish Finder. In most fish finders, you’ll either see dashes, dots, or lines displayed as a baitfish. Bait fishes always appear as groups of fishes in the water. The best way to tell a trophy fish is by using the arch’s thickness.

Identifying Various Types of Underwater Structure

By learning how to read a fish finder, you’ll be able to tell the depth of the water and any other structure in the water. That’s where the depth feature on your transducer comes in.  This feature not only tells the depth of the water, but also gives a clue of the kind of fishes that could be at such depths.

The depth feature is found at the topmost corner of the display. It is measured in meters but you can convert it to your desired unit of measurement. What’s more, you may need to sway or troll your finder at a slow speed to be able to see the outline of the bottom well. This is what will help you identify drop-offs.

Raymarine fishfinder

Once you can see the drop-off, attempt to scan the area once more with a slimmer beam, just to be confident that you have obtained the correct picture. This will also help you do away with dead zone areas while scanning. Remember to set a depth alarm in case you are paddling in a big area, so that you can get an alert once you get to your desired depth.

You will be able to recognize a log or brush from the color on your display. Each structure conveys a conflicting frequency to your sonar, so the colors cannot be the same. You’ll have to choose the correct color palette.

Types of Fish Finders

Different types of fish finders exist on the market based on function and some additional but important features.


A standalone fish finder is a solid, but economical choice for those who do most of their fishing on inland lakes and have a modest-sized vessel. It offers an adequate display by simply hunting for what is around you during fishing.

GPS Combo

These ones work well on medium-sized boats whose owners want to enjoy some navigating component too. The sonar and GPS can be presented at the same time, but each component can also be used on its own.

CHIRP (Broadband)

The broadband fish finder versions can typically discharge much lengthier pulses, giving you close to 50 times more vibration energy. So, the sounds that it produces will vibrate through the water at different frequencies, delivering images in much greater detail.


These units come with all manner of bells and whistles. If you are looking for a wireless fish finder or one with GPS, video, radar, and even SiriusXM radio, these are the real deal.

Portable Fish Finders

A portable fish finder is ideal for anyone who plans on going for a fishing vacation and is looking for an easy to transport model. The best portable fish finders come with a fish finder mount, transducer, display unit, and battery for fish finder.

Ice Fish Finders

Most ice fish finders utilize flashers and unveil a chart of what is happening below. We also have some flashier kinds of ice fish finders that will display a real-time view as well.

What to Consider when Buying a Fish Finder

1) Transducers for the fish finders

Transducers are crucial parts of any fish finder. They cast out and receive sonar waves. Once released into the water, these waves bounce off of various objects. They then get collected by the transducer. The data travels into the central unit where the signals get recorded into a photo on the display, which allows you to read and understand.

hummingbird fishfinder

Note that transducers have different kinds of mounts. The ransom mount is the easiest to install, but if your bat is bigger or you need something more heavy-duty, you can go for another kind, like the thru-hull mount.

Here is what to consider when choosing a transducer

2) Transducer Material

Depending on what kind of boat you have, you need to go for the correct transducer material. For casual fishermen and enthusiasts, a plastic transom mount is just okay. The best part is that they are compatible with most types of boats.

Transducers with in-hull or thru-hull mounts, metal hulls or fiberglass require plastic housings. Stainless steel housings are for steel or aluminum hulls, while bronze housings are perfect for boats with wood or fiberglass hulls.

Recreational users have a variety to choose from as most fish finders come installed with trolling motor transducers or those transducers that have transom mounts. They work well with most boats as long as you follow the right installation guidelines. And, if you’d like to use a thru-hull transducer, you have the option for bronze or plastic material.

3) Beams and Cone Angles

One of the most important aspects to consider when choosing a transducer is the cone angle. The cone angle shows the width of the ray emitted from the boat to the water. A wider cone means you’ll be able to cover a larger area. The cone angle expands as the beam moves down, but that also means you’ll lose sensitivity in deeper water.

Transducer cones range from 9 degrees to over 60 degrees, though most devices are between 16 degrees and 20 degrees. If you are a beginner and intend to fish in various water depths, then a 20-degree cone will be your best bet.

Something interesting about transducers is their ability to release more than one cone from a single point. A conventional transducer only has one beam, but more advanced units can give you multiple. Some come with a dual beam, some with a triple, and some even have a side beam.

Each new beam gives you the power to cover more area. Also, more beams make it easy to cover larger water bodies, like lakes.

You will, however, pay more for units that come with multiple beams compared to those that come with single beams.

4) Personal Preference and Usability

 When buying any tech device, it’s important to ask yourself if you can comfortably and effectively use it. Consider things such as your level of technical capability and needs because, while it’s good to have all the extras, it can only be helpful if you will use them.

This means you could be looking for a simplified design with more automatic features, or that you may need a larger display that allows comfortable reading. Whatever your preferences and capabilities, think about your level of comfort and stick with it. Note that when it comes to display, you have different touch screen capability, sizes, and color to choose from.

5) B/W Screens or Color Screens

Just like in many other electronics, colored screens have now become a standard in fish finders. With millions of colors and a bunch of details, you’ll hardly go for black and white screens which only have 265 shades of gray.

A color screen makes it easier to read and understand the information relayed by your transducer. You’ll be able to perfectly see what’s going one. On the other hand, black and white screens are harder to read, especially in direct sunlight. They also fall short with limited readability during cloudy or dark weather.

However, black and white displays have their place and several models are still being produced. If your budget can’t afford you a color screen, then you can as well start with a simpler black and white display, and upgrade later on when you are able to.

6) GPS Capabilities

While the market is full of fish finders with no good GPS system, they are not really the best choice. GPS allows you to download pre-made maps of various water bodies and their underwater topography, mark waypoints for return, and some even allow for advanced personalized cartography and navigation that offers ultimate customizability.

It’s also good to note that fish finders can have Bluetooth and Wi-Fi connectivity and associated apps that allow you to connect to your device for easier usability. This means you can analyze your data from anywhere on the boat, and evaluate the analysis later on from the comfort of your house.

7) Power supply for the transducer

Before you choose a particular fish finder, it’s important to consider its power. Fishing in shallow water doesn’t require as much power, but if you plan on fishing in deep water lake or saltwater, then you’ll have to buy a fish finder with as much power as possible. This is due to the fact that a fish finder works by converting sonar waves form the transducer.

Less power equals to slower waves, which means the reading won’t be as reliable. More power means much faster waves, which translates to more accurate reading.

8) Wattage of the transducer

The power of the fish finder is indicated in watt RMS. Power is directly connected to how well you are able to see in silt-laden water, scan down to greater depths as well as resolve unconnected targets and botton structure. With a 500-watt (RMS) fishfinder, you should have enough power for most coastal operations. Serious bluewater anglers should, however look for a 1000-watt or more fishfinder. Inland lake fishermen are able to see the shallow base with just 200 watts.

9) Single, Dual, and Multiple Frequencies

Fishfinders work with transducers with different frequencies (single, dual, or multiple) or a broadband CHIRP structure. The frequencies are 50, 83, 192, or 200 KHz. Cone angles are directly related to them.

Generally, higher frequencies give the best outlook from a fast-moving boat and the least background noise on the screen, the finest detail resolution, but doesn’t infiltrate as deeply as the lower frequencies.

For shallow-water fishing, go for higher frequencies such as 200 kHz, 400 kHz or 800 kHz. For deep-water fishing, use 50 kHz transducers.

10) Screen Resolution

As you check out the displays, it’s also important to consider the resolution and the number of pixels your fish finder’s display will have. A pixel refers to a single dot on the screen. So, the more pixels you can see the more detail the screen can put out. For a 320 x 320 resolution, for instance, 320 dots will be moving from left to right, while the other 320 dots will be moving from top to bottom in every column.

Lowrance Hook 5 with SplitShot Transducer

It’s good to target at least 240 pixels x 160 pixels, though this is still on the lower side. If you can afford it, you’re better off buying a higher resolution screen, as you’ll be assured of more detail and crisp images.

Still on screen size, the resolution you have will ultimately affect the quality of the picture you’ll receive from your fish finder. Low-cost options tend to come with smaller displays.

Well, they are good as a second unit or backup, but when you finally decide to buy your main fish finder, then it would be good to go for the largest and highest quality display you can possibly afford. That way, you’ll be able to see your numbers and data in higher display and on a bigger screen.

11) Brand and Affordability

These two factors are inter-connected, so they are better off being discussed together. The truth is that the market is full of crappy knockoffs with poor accuracy, inferior CHIRP systems, and bad designs.

To avoid being disappointed because of poor quality devices, it’s better to just stick with popular brands that have been in the business for a while. When it comes to fish finders, the most common names with good reliability records are Garmin, Humminbird, Raymarine, and Lowrance.

Out of the four, Humminbird has excellent options for particular types of fishing, Garmin comes with one of the best GPS tech, Lowrence has great options for versatility, and Raymarine comes with all the accessories you may want. These brands are also a go-to when looking for the best side imaging fish finder.

The phrase “you get what you pay for” applies here, though these brands together with others with a good reputation have affordable options too. You can actually get the best fish finder under $200. Any good brand should offer tech support, warranty, and any other benefits that will ensure your fish finder lasts a while.

12) Water Resistance of the transducer

Water resistance is crucial especially if you plan on mounting your unit on an open, smaller vessel. Always check the JIS/IPX ratings as they determine a certain unit’s water resistance level.

A device with a rating of four is only safe from splashing water; meaning it won’t work well as a fish finder for kayak, for example. A unit with a rating of 5 or 6 can withstand low to high-tension jets of water. And, with a rating of 7, your unit can be submerged in water of up to 10 feet for a period of 30 minutes. Finally, a unit with a rating of 8 is able to stand being underwater for an extended period of time.

13) Fixed vs Portable Fish Finder

So, what do you prefer; a fish finder that is fixed to your kayak/boat or a portable fish finder? A portable fish finder is an excellent choice for people who engage in a lot of fishing in other people’s or rented boats.

Portable fish finders are self-contained and completely convenient to carry along and power off. You just need to have the best fish finder battery to last you a little bit longer. And, with their easy-to-use suction-cup, you will be able to quickly hook up the transducer ad start fishing.

There are many handheld fish finders from the top brands so finding one shouldn’t be a problem. They are perfect for land-based anglers who have no boat. But, for kayaks and boats, a fixed fish finder that has the transducer mounted at the back of the hull of the kayak or boat will work perfectly.  

What is more unique about portable fish finders is the fact that they are usually available in multiple parts, regardless of the brand you are dealing with. So, with two apparent pieces of equipment, you can enjoy the convenience of a self-contained unit that doesn’t occupy a lot of space, without compromising the quality. 

Experienced anglers can also go for a deeper smart portable fish finder with Wi-Fi connection that you can pair with your tablet or smartphone.

Choosing the best fish finder can be daunting, especially for the novice angler. There’s no one fish finder that can be termed as “the best fish finder” since there are dozens of units manufactured every year, with each owning its place for best use. We hope that this guide helps you penetrate the confusion and marketing buzzwords to finally choose the best device for your fishing style.

Like this article? Then you would definitely love our other article about 7 Best Luminous Watches Under $500 

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Matink is a "Jack Of All Trades" writer and admin at thegadgetsjudge.com. Matink love writing, and reading more about Technology, origin of life and understanding the universe. He is a qualified Master Electrician, Welder, Safety Professional and currently doing SEO and Google IT Support Professional Certificate at coursera.org. Follow Matink on twitter @thegadgetsjudge


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4 thoughts on “Our Ultimate Fish Finders Buyers Guide In Details”

  1. This guide was completely mind-blowing! I haven’t gone fishing in a couple of years but one of my best friends absolutely loves the experience, both of being in the ocean and also fishing. I’m pretty sure this would be an amazing read for her and her father, so be sure I’d be sending this article out to her. She had just gone fishing a week ago, she’s gonna be excited and looking forwards to educating herself more with these type of gadgets. Personally, I wasn’t even aware that there were products like this out in the world. The beauty of the internet is that it makes you learn something new everyday. 

    • Absolutely fish finder make fishing easy and and more enjoyable am happy you enjoyed the Guide. Have also done reviews on different fish finders hope you checked the links I shared.

  2. Hello Matink, I have to say I’m really happy about this gadget and it means a lot to me because I have been going fishing with a couple of friends in recent times and it’s not been really easy because we don’t have something like this at all. I’m very much an amateur and  I really would be happy to have this in my boat when next I go fishing 

  3. It is true, there are times when it can be very hard to be able to find a fish when going for that quest. I heard of using a fish finder and I didn’t know much about it and that’s why I came to your website so that you can give me a good guide on how to go about it and honestly, I am not disappointed with what I have learnt so far. Now I know what to look out for when I want to buy one.


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