What Are Features to look for in fish finders Before Buying?

Fish finders are sonar equipment used to detect fish in a particular range around the boat. Just like other sonar gear, superior quality fish finders do this by releasing a sound pulse and later identifying it when it springs off of a fish.

You may want to buy the right product as per manufacturer recommendation but that sometimes leads to more confusion and disappointment. Don’t despair though as we are here to ensure your buying process is as smooth as possible. We are going to outline all the important features to look for when buying a fish finder. But first, let’s look at three of the best fish finders available on the market right now.

Best Portable Fish Finders

Portable fish finders allow you to carry your fishing expedition wherever you go. You can also switch between boats easily without much hassle. Many companies make portability units consisting of a portable battery, a carrying case, and a transducer suction-cup mount.

Venterior VT-FF001 Portable Fish Finder: This Venterior fish finder is our choice for the best portable fish finder. While this device may not be eye-catching, it does what it’s supposed to do very well, and it’s less expensive. For its price, this product has a wide range in depths, ranging from 3ft to over 300ft.

When it comes to sensitivity, you have five settings to choose from, allowing you to perform things such as setting off the alarm when fish is in range or conserving the battery.

Venterior VT-FF001E Portable Fish Finder

As expected, the Venterior Fish Finder utilizes a transducer, and it is connected to a 25-foot cable, which enables you to get a reasonable detection range.

Unlike other fish finders that require resetting of the settings every time they are started, this device remembers all your settings even after shutdown, so you’ll not need to reset them.

If reliability and affordability are the two most important features for you, then you’ll surely love this fish finder. Your scans will, however, not be displayed in colors, and there are no elegant display methods.

Your information will instead be displayed in black and white. But, if you need something a little bit more complicated, then you can read the best portable fish finders’ reviews to see what suits you.

Other than just scanning fish, this device also tells you the depth of the water, and also tells you where the sand, tall plants and rocks are. The screen also has backlight setting that helps you see at night, so you don’t have to be restricted to fishing during the day. It has a GPS feature, uses disposable AAA batteries, and works at even 0ºF temperatures. Unfortunately, the screen is not water-resistant.

Best Fish Finder for Small Boats

As much as it could be tempting to try to fit the largest possible fish finder on your small boat or kayak, it’s not really the best choice as it always gets in the way.

Screens 4 inches or below are perfect for kayaks and small boats, 5-inch screens may be a little cramped, while screens above 5 inches will be way too much and the only way to mount would be by using a ram mount.

PiranhaMAX 4
PiranhaMAX 4

The good news is that you can get good inexpensive fish finders for kayaks and small boats on the market easily. An example is listed below:

Humminbird PiranhaMax 4 At just under $100, the Humminbird PiranhaMax 4c delivers sound performance with both traditional Sonar and Down Imaging. It also comes with the attractive extras present in other Humminbird fish finders, including screen zoom, depth alarms, and fish alarms.

Best Hummingbird Fish Finder the Humminbird ICE-45 T.

Hummingbird fish finders are well-known to be easy-to use, technologically advanced, intuitive and precise. Here is our choice for the best Hummingbird fish finder based on features such as price, display resolution/size, and ease of use. This is also a good choice for people looking for the best ice fishing fish finders.

Humminbird ICE-45 T.
Humminbird ICE-45 T.

Available in 5 different designs, the Humminbird ICE-45 T gives you a deeper and clearer understanding of what is beneath the ice, with unique features that cannot be found anywhere else: unprecedented viewing options specific to ice fishing, Dual Spectrum CHIRP Sonar, CHIRP Interference Rejection settings, and built-in GPS with Hummingbird’s Basemap. This device is made from top quality material and is perfect for both indoor and outdoor use.

How to Read Sonar Fish Finders

Here are some of the methods you can utilize to interpret your fish finder properly.

Speed Sensor

Speed is a vital element when using a fish finder. It is therefore, very important to always note your speed. The speed sensor is your fish finder’s speedometer tool.

Note that, depending on how sonar waves are emitted, some products may not perform very well at a higher speed rate. So, it’s good to try the product at different speeds as you record the quality of your imaging.

The Depth of Water

The depth of the water on any fish finder is displayed in meters and feet. The accuracy of the reading will mostly depend on the particular model you are using. The depth sensor can sometimes be found on the transducer part.

Depth gives you a clue on the kinds of fish that are in a particular water body.

Reading the Display Screen

Start reading from the right side all the way to the left side; noting that the far right side has the most recent images.

(a). Darker colors tells you that a stronger echo is being emitted

(b). Thick lines denote harder structures beneath the boat

(c). While some models display raw data, others go ahead to convert it into fish icons by the use of Fish-ID technology that is found on newer models.

(d). Even sonar waves are displayed

It’s advisable to test your fish finder by casting it out several times, and noting what you found in reference to a later trip’s findings. This should include taking note of the depth at which the fish was found.


A chartplotter helps you keep track of your current location and where you ought to go. What’s more, it will tell you how deep the water is and the structural composition beneath the water. This helps in tracking those fishing sites that have been exceptionally good.

The chart plotter helps you plan the course every time you head out to that particular spot and can even establish a trail around exceptionally treacherous underwater structures.

You can use a split-screen image (one side for finding the fish and the other side for chart plotting).


For those fishing in shallow water, zoom equipment will help you to look up to the last 10 ft. of water, enabling you to capture the correct underwater contours in the area. This way, you’ll be able to tell the kinds of fish in that specific spot and also cold and warm pockets of air for various groups of fish

This will, however, not work in very deep water as the contour of the base is not as important. Be careful not to employ a high frequency in a water body that is full of algae, as this will lead to false reading that may end up frustrating your fishing trip.

How to Choose a Fish Finder

So, how do you settle on a particular fish finder? To start with, put in mind where you’ll be fishing, how you will be fishing, why you are fishing, and how much you are willing to spend.

Once you have answered the above questions, you can now move to more specific questions and see what feature to look for:

1. Transducers

Which transducer? Transducers are the major units on a fish finder that allows you to see what is beneath the water. They do this by sending the sonar cues into the water, which bounce off of objects submerged in water, and get collected again by the transducer. This device sends the data it collected to the main segment, which translates these signals into the picture that you can see and understand.

Decisions include: what mounting are you going to use—transom mounting or thru-hull? Most fish finders use transom mounted traducers as they are the cheapest and simplest to install, and they suit most boats. However, these kinds of transducers can be vulnerable in their unmasked location on the transom.

So, as your needs or those of your boat get more advanced, it’s good to go for other kinds of transducers like the thru-hull. This type of mounting gets the transducer out of harm’s way, though it requires that the boat be outside of the water. Also, its installation involves a hole being drilled through the hull.

Another thing you need to consider when choosing a transducer is what you would like to see on the screen as different features offer different results. Here are the options:

SideScan: offers you a wider view, enabling you to identify the structures that are on either side of your boat.

DownScan: Shows the outlook of the bottom under your boat. Use it to view the bottom structure where fish is likely to hide and cast your lure right in.

CHIRP Sonar: Shows the fish that is in the water column just below the transducer. With FishReveal, you can actually overlay DownScan and CHIRP Sonar technology on one page.

StructureScan 3D: Enables you to see authentic 3D model of the base below your boat.

Based on the particular fish finder you go for, it’s possible to have all the above technologies in one transducer.

Fishfinder, Chartplotter or combo? Are you looking for fishfinding as well as chartplotting capability? This will determine which model you go for. If you’ll need to track or delineate where you are fishing, plan a route, or see the depth, then you’ll require a chartplotter. But, if you just want to launch and fish from a kayak, then a fishfinder model or a castable may be all you’ll need.

2. Frequencies—Single, Dual, or Multiple

 Frequencies are another big factor in transducers. Most transducers come with 200, 192, 83, or 50 kHz frequencies, all in direct connection to the cone angle. Most dual frequency transducers come with both the 20 and the 60 degree cones.

Low frequency transducers like the 50 kHz work best in deep water and are better used for commercial fishing and by professionals, while the higher frequencies such as 192 and 200 kHz are best for use in shallower water.

Note that the highest frequency gives the most details on the screen because of the many sonar waves being dispatched out and collected by the transducer. Therefore, if you generally fish in shallow waters, then it’s better to go for the highest frequency. Some models even come with a whopping 400+ kHz as well as multiple frequencies that will allow you to see incredibly detailed images and enable you to shift between them for narrower, broader, more general, and more detailed views.

Important Tip: If you already have a transducer, or you intend to buy it separately, make sure your fish finder model will work perfectly with the frequency specifications outlined by the manufacturer. This applies to both portable and mounted fish finder models.

Also note that a dual frequency transducer is probably the surest bet for error-free fish readings. As the name suggests, beam or dual frequency models have two different beams projecting at different frequencies. One beam is positioned to a low frequency while the other one to a high frequency.

Most fish finders will allow you to switch between these two beams on the screen. There are also units that come with a split screen display, allowing the angler to view pictures from both beams individually at the same time. 

What’s more, some manufacturers have displays that merge the images from the two beams to one image. The display basically combines the deeper search proficiency of low frequency and the clear detail of the high-frequency with the wider beam.

For deep water fishing, it is recommended that you use dual frequency transducers because they use low frequency-wide beam setting to help you find the general range of the angle over a large pool of water, and then for greater precision, pinpoint the location and depth using the high beam-narrow cone setting to offer greater clarity. 

Shallow fishing on the other hand works great with high frequency as you won’t need to view fish in greater depth.

3. Transducer Material

The material that the transducer is made of also influences the performance of your fish finder. As expected, a poor-quality transducer will not efficiently transfer the fish finder’s power into the water. And, a weak signal leads to poor fish detection, poor interpretation and substandard depth capabilities.

Transducers come in various kinds of materials, with each suited to a specific type of boat. Most fish finder units have their transducers made of plastic material, which is perfectly okay for most sport/casual fishing.

For thru-hull or in-hull transducers, plastic housings are perfect for metal or fiberglass hulls. Stainless steel housings are better for aluminum or steel hulls. And lastly, bronze housings are better for wood or fiberglass hulls.

Most fish finder models meant for recreational fishing come with either trolling motor transducers or transom mount transducers, which works well with any kind of boat. Don’t forget to install them correctly!

If you plan on going for a through-hull transducer, there are two choices of material—plastic and bronze. And, for wooden hulls, it is recommended to go for bronze and not plastic as the expansion of wood may damage the plastic transducer, which may end up inducing a leak.

Note that you’ll need an insulating fairing to install stainless steel housing to a metal hull. Again, a transducer with metal housing should not be installed on a boat with a positive ground system.

4. Power of the fish finder

Power is a very important factor to consider when making your purchase. The power of a fish finder is calculated in wattage (W). So, the higher the wattage, the speedily your device can display the readings, and the more profound your readings can be. On the other hand, the lesser your wattage, the slower the readings will be displayed.

This is because the fish finder interprets the sonar waves it collects from the transducer, and if the general power is not enough, the sonar waves are likely to be slower, which ultimately makes your reading to be fuzzier. And, if the general power is more, the waves are likely to be much faster and the reading clearer.

Note that the shallower the water that you are fishing in, the lesser the power you’ll need. If you intend to be fishing in deep waters such as salt water bodies or the great lakes, it’s good to go for the most impressive fish finder (in terms of wattage) you can afford.

Remember, at 50 kHz, and for every 100 watts power, your transducer/finder can display readings of up to 400 feet. And, at 200 kHz, and for every 100 watts power, your transducer/finder can display readings of up to 100 feet.

There are many mid-range finders available on the market with dual frequency to allow you to view recordings from both frequencies in split screen technology.

5. Black and White Screens Vs. Colored Fish Finders

Grey scale displays or monochromes show pictures in shades of grey or black and white. The low-priced fish finder models may lack grey scale completely or have a 4 level design grey scale. What this means is that there won’t be too much distinction on the screen for different objects.  The high-end models may come with up to 12-level grey scale to each pixel. The higher level allows for more object contrast and definition.

Color displays are the new trend in electronics. These displays allow for greater detail, displaying more than a million colors compared to a mere 265 shades of gray. Color fish finders will make fish as well as underwater structure to truly stick out from the screen, making it way simpler for you to catch sight of what is going on.

Another advantage of color screens is that they are easier to read in bright light compared to black and white displays, and they can also withstand all weather conditions, dark or cloudy.

Color displays are, however, more pricey, and you will also be required to pay more as the resolution of the screen increases. Generally, color displays actually come with fewer pixels compared with monochrome fish finders, though every pixel carries up to 256 color options.

Using a good color fish finder ensures you get clarity even in direct sunlight, helps distinguish fish images from images underneath the boat like sand, rock, weed, foul etc, and also helps you tell the difference between fish species.

So, while black and white units are still available, you’ll have more fun using a color screen. Unless your budget can’t allow it, then it’s better to avoid the black and white models.

6. Cone Angles and Beams.

Another important factor when choosing a transducer is the cone angle. This refers to the width of the beam sent from beneath the boat into the water.

So, the wider the angle of the transducer cone, the larger the zone will be covered.  As you move deeper and deeper into the water, the cone becomes wider and wider. But, note that as the cone angle becomes wider, the sensitivity begins to decline in deeper water.

Transducers feature cones with angles ranging from 9-degrees to over 60-degress. Most models usually have a range of 16 to 20-degress. For anglers who intend to fish in varying water depths, a 20-degree cone will be an excellent choice.

One of the best features of transducers is their ability to have over one cone broadcasting from the same exact starting point. In short, the basic transducer comes with a single beam. But, as you become more and more adventurous, you can upgrade to a side beam, triple beam, dual beam and so forth. Note that each extra beam helps you explore more and more water—a good thing to have if you are fishing in a lake.

While there are models that come standard with these extras, there are others that will require customization. And, you will pay more for these significant advantages. Another point to note is that dual beams are way better than single beams, especially if you are fishing in relatively shallow water, since they will spread out to more water effectively.

7. Water Resistance of the fish finder.

Another, more important consideration is water resistance. If you plan on mounting your device on an open, smaller vessel, then you have to consider water resistance. Always look at the JIS or IPX rankings as they determine a particular model’s water resistance level.

A 4-rating means the device is shielded from splashing water, so it won’t be good for fishing on a kayak, for instance.

A 5-or-6-rating means the fish finder can withstand low to high-pressure gushes of water. A rating of 7 means your unit can be submerged into up to 10 feet water for about 30 minutes. And lastly, a unit with a rating of 8 can be submerged in water for a long period of time.

8. Screen Resolution of the fish finder

It is also important to consider the total pixels your fish finder screen is able to display. One pixel is displayed as one dot on the screen, and this dot represents the smallest amount of element your screen can display. All of the dots combined are what you are ultimately able to see.

Let’s assume your screen is 640 x 640 pixels: what this means is that each raw has 640 dots going from right to left, and also 640 dots moving up and down in each column.

The more the number of pixels available, the more detail you are likely to see. At the very least, you should look for a monitor of 240(v) x 160(h) pixels. But, even with that, the picture will be quite blocky. For crisper, sharper images, you’ll be better off going for a higher-resolution screen.

Together with screen size, screen resolution is what will determine how crystal clear your display will be. The less expensive models usually come with smaller screens, making them good options for secondary or backup fish finders.

But, if you are on the market for your main unit, then it’s advisable to choose the biggest possible size. This is to ensure you get clearer images, since the numbers, data, and echoes will be evenly spread out and painless to see and differentiate.

9. GPS capability of the fish finder.

Some fish finder models come with GPS capability to help you keep track of the exact place where you found the most fish, so that you can easily come back the next time. GPS also helps you see the waterways that are around you and help make navigation much easier.

10. Availability of Maps on the fish finder.

You may also want to confirm if your fish finder comes with maps installed beforehand or if they are available for download. Most manufacturers provide up to date maps of waterways for download on their websites.


Whether you are looking for fish finders for dummies or the best side imaging fish finders, finding the best device doesn’t have to be daunting. We hope that we’ve pointed you to the right direction and that you will use this guide to buy the best fish finder for your fishing needs.

Like this article? Then you would definitely love our other article on 8 Luminous Watches Review To Tell Time in Low Light

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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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