If you want to place a lure correctly, you need the right electronics. With the constant flow of technology, it’s refreshing that there are still quality fish finders for under $400. Read on to get a comparison of the best fish finders under $400 and all the background information you’ll need to choose your own with a discerning eye.
500’ CHIRP, 300’ SideScan & DownScan
Garmin Striker Plus 7Cv
2,300’ freshwater, 1,100’ saltwater
Humminbird 410210-1 HELIX 5
Up to 2,500 feet
Garmin 010-01872-20 Striker Plus 5
1,600’ freshwater, 750’ saltwater
How Fish Finders Work & the Benefits of Using Them
Like a beefed-up pair of x-ray specs for fishermen, fish finders are sonar devices that show you where there’s cover, structure, and, of course, fish. Sonar waves are sent out, bounce off the bottom or whatever’s in between, and are received back at a suspended transmitter called a transducer.
Transducers work differently in saltwater, freshwater, cold water, and even brackish water. If you are new to fish finders or don’t want to remove yours every time you go kayak fishing, a fish finder under 400 performs in more or less the same way as a more sophisticated model.
Tips for Choosing a Quality Fish Finder for Under $400
Durability is always the most important factor when it comes to the construction of fishing electronics. Fish finders, especially when they’re castable (meaning you can cast them with your rod), need to be able to handle all sorts of conditions.
Most are portable but can also be mounted to a boat or a holder on a kayak. If you mount a fish finder on a boat, it’s usually through the hull or on the transom, which is a thick vertical section at the stern of the boat. There are many universal mounts and some designed specifically for aluminum boats.
Probably the most essential aspect of any fish finder is the transducer. They can be designed for ice fishing or all-purpose. Transducers transmit sonar in a cone shape. The beam can shoot straight down (down imaging) or out to the sides of the boat (side imaging)—the lower the frequency, the wider the cone.
The best fish finder will be dual-beam, having two or more frequencies to use at different times, depending on the depth of the water. Many anglers sweep with a wide cone first and return to use down imaging in specific spots later.
All the information from the transducer has to show up somewhere. The screen should have a high enough resolution to show clean target separation. A high resolution means a higher number of pixels on the screen, which translates to a higher level of detail.
Since most are now in color, black and white fish finders are generally the mega-cheap option and relics of a bygone time. The screen can also be backlit for use in lower light, but it should also be visible in bright sunlight.
CHIRP vs. traditional sonar
CHIRP, or compressed high-intensity radar pulse, is basically a high number of traditional sonar waves that are sent out at the same time at varying frequencies. We’ll go into more detail after the fish finder review and comparison, but suffice it to say for now that CHIRP gives more detailed information about activity in the water column and features of the floor than traditional sonar does. If you’re on the market for a fish finder, spring for one with CHIRP.
High-frequency sonar brings back a much clearer picture in greater detail, but the waves won’t reach the same depths as a low-frequency will. Like I mentioned before, many anglers will pass over the central parts of a body of water to get a general look at what’s underneath the surface with a low-frequency scan and return to get a more detailed look with a high-frequency scan later. A high-frequency scan is much better for targeting a school of fish that’s right underneath your boat.
Additional useful features on a fish finder that will save you lots of trouble are an SD card slot to keep everything up to date, side-scanning for shallow water, and a screen that’s readable from any angle. The SD card slot is handy not only for exporting maps scans from the fish finder but also for adding new pre-made maps and updating other software.
Side-scanning is useful to get wide and shallow readouts beyond the comparatively narrow water column ordinarily visible. You should be able to see what's happening on the screen, even if you need to stand up.
Like other outdoor equipment, fish finders often come with some sort of warranty from the manufacturer. Look out for the language when it comes to these warranties, though, because sometimes the device is not covered for as much as it sounds like.
A lifetime limited warranty, for example, can sometimes mean the device is protected for its whole life, but only against defects that occurred during the original making of the product. You also usually need to register a fish finder when you first get it if you want to make good on a warranty later.
5 Best Fish Finders Under $400 Reviewed
1. Lowrance HOOK2
Our Top Pick!
Transom, hull, motor, scupper hole
500’ CHIRP, 300’ SideScan & DownScan
1-year manufacturer’s warranty
All the benefits of a fish finder have been streamlined on this model from Lowrance. It’s meant to be put to use as soon as possible without having to fuss with different settings like transducer sensitivity, display setting, and depth levels like you would on competing models. The main attraction with the Lowrance HOOK2 is the autotuning feature, which automatically adjusts the device’s sonar settings to better align with changes in the water so you can get right to fishing.
Thanks to the TripleShot transducer that’s included with this model, there are three ways you can take a look at the water beneath you. The CHIRP sonar mode gives real-time information and superior target separation while the SideScan and DownScan options provide a great look at what’s going on under the boat or off to both sides of it.
You can view all three scans with the helpful split-screen feature. The best thing about the CHIRP on this model is its wide-angle coverage, which will show more of what’s down there than you’ll find on other fish finders of this size.
There aren't tons of buttons on this Lowrance, and it’s really clear which ones do what, so you won’t have to spend additional time trying to figure out how you’re supposed to use the thing. Maps are available with C-MAP and Navionics so you can get some idea of where to start when you first get out on a new body of water. You'll have to find the maps yourself with these services, but you can always upgrade and get new maps with the SD card slot built into this device.
For peace of mind as a consumer, Lowrance promises a manufacturer’s warranty for one year, which protects against manufacturing defects. There’s also an upgrade program that allows you to upgrade to more current technology if this Lowrance fish finder breaks down at any point in the five years following its purchase.
2. Garmin Striker Plus 7Cv
Best Garmin Model (Runner Up)
Flush or pedestal mount
2,300’ freshwater, 1,100’ saltwater
Two CHIRP sonar modes allow you to see reasonably sharp images of what's going on underneath the boat with this best Garmin model of fish finder. While the screen is two inches larger than our top pick, this model takes a bit longer to set up and has one less viewing mode. The screen is visible in bright sunlight as well.
This is a Garmin fish finder, so it should be no surprise that it's got industry-leading GPS mapping. It can store a fairly large amount of contour maps and makes setting waypoints really simple. Everything you do on the map with this fish finder is exportable and easy to view on other devices since it’s geolocated on the map if you want it to be.
There’s a tilting/swivel mounting stand included with this model that makes it easy to put on your boat. The transducer cable is between two and five feet longer on this model than on our top pick. The device is relatively portable, but it doesn't take batteries. You'll have to connect it to a boat battery or other 12v power source to use it.
The traditional sonar mode and ClearVu mode both have three frequency levels. For the traditional sonar, the possible frequencies are 50, 77, and 200 kHz, while ClearVu transmits at 260, 455, and 800 kHz. Unfortunately, the CHIRP mode only has the option to choose a medium or high frequency. That being said, the mapping on this fish finder makes it the best fish finder 400 from Garmin.
3. Humminbird 410210-1 HELIX 5
Value For Money Option
Up to 2,500 feet
1-year limited warranty
This screen is high-res enough to display really detailed information, and the transducer is sensitive enough to show what's going on in the water at a level of detail that is surprising at this price point. This value for money model is not only under $400 but takes it a step further by ringing up for under $300. It’s a common fixture on best-of fish finder lists and for good reason.
The CHIRP sonar can identify individual fish, the SwitchFire sonar can help you see your lure in the water, and the dual-beam PLUS offers two frequency widths so you can do a wide sweep and return to hot spots for a more detailed scan later.
Humminbird has included a vast number of pre-made maps with this model, which should help you get your line in the water much faster if you're fishing in the right place. Ten thousand lakes and coastal coverage makes it likely that the more popular fishing spots you visit will already have some information stored on the device.
There is also eight hours’ worth of recording time on the device so you can record the entire experience of mapping a fishing trip for later review or to share with your fellow anglers. This device is also Navionics-compatible if you do want to look for additional maps.
The side imaging on this model gives really clear images of what’s going on on either side of your boat because it merges new images with the ones taken just beforehand to create a crisp, detailed picture. Overall this is a great model, but if you aren't familiar with how to read fish arches, then there will be a slight learning curve for you.
4. Garmin 010-01872-20 Striker Plus 5
Best For Ice Fishing
1,600’ freshwater, 750’ saltwater
Finally, Garmin gives us the best fish finder for ice fishing under $400. This model has a transducer that is designed to work in colder water and allows for all the best features of Garmin fish finders to help you find fish in cold weather conditions. The CHIRP sonar gives really clear image returns and crisp target separation so you can identify which of those lethargic suspended fish are the ones you’re trying to pull up onto the ice with you.
It wouldn’t be a Garmin without great mapping ability. This model allows you to store up to 2 million acres of 1-inch contour maps with its Quickdraw function. Since this model is meant to be used for ice fishing, they've also included a flasher mode, which is super helpful if you know how to read it and an excellent opportunity to start learning if you don't know how yet. The portable carrying case makes this fish finder easy to transport across the ice on a sled.
The transducer sends out its sonar in 16-24 degree beam angles to give you all the information you need about conditions and fish in the immediate vicinity. It's beneficial to be able to mark waypoints on a map and also use a flasher to monitor your jig all on the same device. You can even turn this into a warm-weather fish finder, but it will require the purchase of another transducer.
5. Humminbird ICE-45
Best Ice Flasher Under $400
2-year limited warranty
Continuing with models meant for ice fishing, Humminbird has created a great dedicated ice flasher with this model. While the outer ring will display all the information you need in the standard 3-color display you’d expect to find on most ice flashers, there is also a center LCD screen that makes some of the information simple to see and understand in a snap. It still has the dual-beam sonar and zooming capability you’ve likely come to expect if you’ve come into contact with lots of fish finders.
One thing that's nice about this model is that, in addition to the auto depth range, you can also select between 1x, 2x, 4x, and 10x zoom to suit your needs. The LCD display can also help you see where the bottom is quickly so you can adjust your depth settings accordingly if need be. This model comes with a 7-amp battery and a wall charger so that you can charge it up for a fishing trip and not have to worry about running out of power in the middle of a fishing trip.
If you’re looking for an alternative ice flasher, we’d recommend this GP1812 from Vexilar. The Vexilar has an additional 3x zoom level and shares many of the most convenient features of the Humminbird with a few extra advantages. While these are both great ice flashers, remember that they are specifically designed for ice fishing, and they won't convert into warm-weather fish finders, so you should really think about how you want to use your fish finder before you invest in either one of these.
Comparing CHIRP to Traditional Sonar
Traditional sonar is a single wave at one frequency that goes out, hits something, and bounces back to be interpreted. CHIRP is the same idea, but rather than one wave; it's a series of waves at different frequencies that are all shot out and return with information to be compiled into a single usable image. With Garmin models, Clearvu (down imaging) is used when you're right above your target, and Sidevu (side imaging) is used to see what’s happening on either side of your boat.
How to Install & Operate a Fish Finder
The vast majority of fish finders will fit a universal mount and screw into the side of a kayak or boat. There are some more complicated ways of mounting a fish finder to a boat as well, including mounting it to the transom, placing the transducer in the hull, or threading it through a scupper hole or something similar. In any of these methods, you won’t have to worry about sending out the transducer before you start fishing.
It can be challenging to understand how to read fish finders at first, but all you need to do is get the right settings for a crisp image and clear target separation so you can see cover, structure, and fish with ease. Check out this video for more information on setting up a fish finder:
Care & Maintenance
Taking care of a fish finder is simple most of the time. All you need to do is go over them with a damp rag to remove any salt or other buildups. Make sure the device is dry before you put it away. You can also invest in an inexpensive cover to keep the screen protected from the elements while the device is in transport or onboard your boat. It's best to clean your fish finder after each use. It only takes a second, and you can keep the device stored just about anywhere dry once it's clean.
People Also Ask (FAQs)
Which is better, down imaging or side imaging?
It’s not always going to be one or the other in this case. We can’t stress enough how nice it is to do a double sweep, once with side imaging and again in select spots with down imaging. When you actually have a lure in the water, you’ll want to use down imaging, but to get a general idea, side imaging is really useful.
What other fishing gear should I have aside from a fish finder?
Not to be glib, but make sure you have a fishing rod with you, at least! Get the right reel setup, fishing line, lure, and other tackle you might need. If you're going ice fishing, make sure the sled contains an augur, flags, and some kind of shelter depending on how long you’ll be outside. Stay warm in any situation with a rain jacket or snow gear.
How accurate are fish finders?
Fish finders work like the sonar you’ve probably seen in submarines or other war movies. They're going to pick up whatever is there, but if your settings aren't just right, then they'll also pick up a bunch of stuff that is there but isn't a fish.
Don't expect the fish to jump onto your boat just because you have a fish finder. But if you are trying a true angling method, fish finders are accurate enough to show you useful things like cover and structure in addition to where the fish are.
Do fish finders work in rivers?
Sure! They do work in rivers, but make sure you do your research to understand where fish hide in rivers versus where they hide in lakes and other bodies of water. There are often pockets with no water resistance along the banks of a river where fish can hang out with no stress. Use a fish finder to find those places and drop a line in, and you're sure to reel something in.
What are the differences in finders to consider when ice fishing?
The most significant difference is the temperature of the water. Waves travel differently through different mediums, and the slower movement through cold water can affect how the fish finder reads information. The transducer is different, especially for a flasher. If you want to go ice fishing, the best thing we can recommend is to learn how to read the round display of a fish flasher.
Is Garmin better than Lowrance or Humminbird?
Not absolutely, not all of the time. Garmin is an excellent brand for GPS and all things tracking, but Lowrance has tons of great fish finders on the market and tends to bulk them up with great features and make them super easy to use.
Humminbird has some of the most classic pieces of equipment on the market, and many industry standards came from the design workshop at Humminbird without a doubt. Make sure you look at the specific performance of each piece of equipment regardless of the brand name.
Where can I buy these fish finders for less than $400?
Unlike some larger pieces of equipment like kayaks, there's not much need to bend over backward, finding a place where you can see a fish finder in person before you buy it.
With so many helpful reviews and tips from anglers on the internet, you can find everything you need to know before you buy from the comfort of your own home. That means if you’re going to buy a fish finder, Amazon is probably your best bet.
No angler should leave home without a fish finder. Luckily, some of the best fish finders are available for $400 or less. Look no further than our top pick, the Lowrance HOOK2 5”, to see that all of the mainstays of fish finders that make them so handy on a fishing trip can be found on less expensive models.