Sonar units, or fish finders, come in several varieties, capacities and prices.
Because they deal in sonar technology, the common angler often becomes mired in the linguistics of these devices, from kilohertz, to wattage, to surface noise, to arcs, to side-scanner and down-scanner.
The last thing any angler needs is to get lost on the way to finding the best fish finder that suits their purposes and their watercraft.
Especially if you are shopping for a fish finder for the first time, a little guidance and translation doesn’t hurt.
Bone up a little through our buyer’s guide farther along in this article and via other sources as well, but in the meantime, consider these top seven sonar units on the market and what puts them on our field experts’ list.
- The 7 Best Fish Finders – In-Depth Expert Reviews
- Buyer’s Guide: How to Choose a Good Fish Finder
- Fish Finder FAQs
- Which brands make the best fish finders?
- How important is a unit with both GPS and Sonar?
- What should come with my sonar/GPS unit?
- How long do these devices last?
- Can I store data from my fish finder to another personal device?
- What can cause interference with my fish finder?
- Can I use the same fish finder for shallows, deep water and on ice?
The 7 Best Fish Finders – In-Depth Expert Reviews
1) Editor’s Pick: Garmin Striker 7SV- Best Fishfinder GPS Combo
Best for: Highly mobile anglers who want to get to their favorite spots quickly and easily while getting highly detailed info from a unit that won’t divot your bank account.
- Simple and precise navigation cues
- Easy to hear sounder (fish alarm)
- Comes with both a transom and troller-motor mount
- Solid screen of 3.6 x 6 inches and 800 x 480 pixels with ample backlight
- Very tough yet fairly light at 1.5 lbs.
- Great depth capacity at up to 2,300 feet in freshwater
- Takes some acclimation to decipher the significance of color intensities and shapes on the screen
The Garmin Striker 7SV falls just within the mid-range price bracket of fish finders.
Indeed, its value on the dollar spent is one reason it beats out our more expensive picks—all while delivering just as brilliantly as any other unit on the market.
First, it incorporates both sideways and vertical scanning cones to give anglers a great vantage point to what lies immediately below and what lies ahead simultaneously on a split screen.
Second, its navigational prowess allows the angler to easily get back to the honey hole he or she discovered on the last fishing trip or even during the same all-day outing.
After all, Garmin is all about pathfinding from its origins in the GPS industry. You can save the bearings of your most successful spots, gain estimated arrival times, know the distance to these haunts and receive turn-by-turn directions via waypoints.
This swivel-mount unit also tracks speed and tells you maximum speed allowed for finding the fish you seek. All of this minimizes the chances of any day-long trolling fool becoming disoriented after coursing miles and miles of sea or lake. It also incorporates a range of frequencies to adjust to the depths or bottom types you encounter.
The Striker 7SV monitor does not compromise technical savvy for readability. Though its screen replication of fish relies on the basic arc symbol, which requires a bit of a learning-curve for fish-finder neophytes, it enhances a fish-shaped arc with more detail via colors and densities to better differentiate between real fish, their actual sizes and simple flotsam suspended in the water.
You can even detect your jig and its proximity to the bottom and the fish when still-fishing. The Garmin Striker is a great navigation and fish-finding tool for the seasoned angler or the newbie to sonar units.
2) Humminbird Helix 9 DI GPS
Best for: The angler who doesn’t mind the price tag for a luxury fish-finding display while relying on decent GPS capability in saltwater and freshwater.
- 360-degree imaging
- Great screen display
- Decent navigational storage of favorite fishing spots and directions
- Self-charted mapping
- Quick data processing with 4,000-watt power
- Limited side scanning
- Sound quality not as great as Editor’s pick
Though the Humminbird Helix 9 DI only supports down-imaging or scanning in water deeper than 150 feet, it packs a lot of reader-friendly features into its jumbo 9-inch screen, one of the largest in the market.
Also combining GPS with sonar detection—like our editor’s pick—this unit adds the capability of connecting your boat’s other electronic devices to monitor all of them on one screen—even missed calls and messages via Bluetooth on your smartphone, a sure killjoy to the purist but a savior for business owners or family devotees needing to stay connected.
The busy angler will encounter few difficulties reading this 9-inch display with a pixel resolution of 800 x 480. The depth, speed, temperature and other readings are larger and easier to read than the average fish finder as a result. Its LED backlight complements a two-dimensional sonar to more easily identify fish by down-scanning depths up to 1,500 feet in both saltwater and freshwater.
As mentioned, if you are a shallow-water bass angler, you can gain sideways scans on a split screen. The GPS on this waterproof unit includes internal storage of up to 45 routes, 50 trails and built-in cartography data on 3,000 lakes across the U.S. You can also create your own map of contours in lake or sea via its sonar data, including overlays if desired.
3) Raymarine Dragonfly 7 Pro
Best for: The angler demanding a highly detailed screen and easy to operate unit that doesn’t charge an extra $200 or $300 for the quality.
- Wi-fi data streaming
- Extremely fast bottom tracking
- Easy to operate
- Highly detailed CHIRP imaging
- Good value on the dollar spent
- Display can be hard to see under a very bright sky (pick a shady part of the deck or attach a visor-cover
- Void of a backlight (need auxiliary lighting at night)
- Software not upgradeable
A little more realistic on the pocketbook but not exactly inexpensive, this high-resolution GPS unit and fish finder features side scanning and down scanning simultaneously or independently, just like the Editor’s pick.
The Raymarine Dragonfly 7 Pro also uses state of the art CHIRP (compressed high intensity radiated pulse) technology to convey nearly photo-quality images on the 5.7-inch screen. Images prove easy to detect even in bright mid-day conditions. Its depth capacity does not match the top two picks but still brings the angler’s eyes down to 600 feet with high-velocity bottom tracking as well—a hull saver in the shallows.
Its built-in GPS receiver features 50 channels, mapping and navionics charting. Like the Humminbird Helix, the Dragonfly keeps an angler connected with a wi-fi mobile app that actually allows the skipper to stream navigation data to angling friends or another personal smart device for later reference. Moreover, the Dragonfly is probably the most intuitive and easy to operate of all our picks. You will not need to drown yourself in the manual.
4) Lowrance Elite-7 TI
Best for: Money-is-no object anglers who like to monitor and store a lot of details while cruising for fish.
- Good image clarity
- Good chart and data storage for historic reference
- Wide frequency range
- Can navigate motor to chosen destination
- Because it’s a touchscreen, saltwater or other fine airborne particles can deter operation
- Must turn off CHIRP to side-scan
- Some claim difficulty with installing transducer
The Lowrance Elite 7 TI Touch Combo heaps feature after feature onto the angler’s plate, thus its spendier status in comparison to some of our picks.
Its keen sonar abilities include CHIRP technology, down-scan and side-scan viewing with great clarity on a 7-inch screen. Also techie-oriented with wi-fi and Bluetooth capabilities, this unit is nearly as intuitive as our No. 3 pick (to wit: instructions for connecting iOS devices proves confusing).
Of course, its touchscreen chart plotting and fish-finding controls outshine your run-of-the-mill fish finder/GPS unit priced a few hundred bucks less than this unit.
The Elite-7 offers two options:
- the pricier TotalScan model which features a transducer that hosts broadband sonar, the aforementioned CHIRP imaging, StructureScan HD screen; and
- the same unit but with only a down-scan capability and sans the StructureScan HD.
Like the No. 3 pick, images appear almost photographic and well discerned on the screen because of its multiple frequencies (83/200/455/800 kHz). It navigational prowess one-ups our other picks with a backtracking feature that lends you a view to the past: the day’s history of baitfish, your sought-after fish and bottom structure from various coordinates on the water.
Moreover, it offers eight preset page layouts and not only a split-screen view of side and down cones, but a three-screen view that includes charting of up to 3,000 waypoints, 100 routes and 100 trails. This Jim Dandy even coordinates your steering (via Xi5 Trolling Motor control) to your boats path in accordance to a selected route.
5) Garmin echoMAP CHIRP 73sv
Best for: Anglers who fish a lot, cram a lot of info into their fishing year and want to know everything about their next destination regardless of what they pay.
- Technologically loaded for data gathering and navigation
- Superb scanning detail due to CHIRP technology
- Lots of auxiliary connectivity
- GPS that relays more than just in-water data
- When connectivity and screen views fully engaged, almost intimidating
Staying at the higher end of pricing, the Garmin echoMAP CHIRP 73sv offers a lot of preloaded data up front to complement a sea of bells and whistles—including great screen detail and resolution—in defense of its price tag.
The key to its screen clarity and detail lies in its CHIRP technology, which rapid-fires multiple frequencies from low to high range simultaneously, instead of running through each frequency one at a time. This results in a greater pulse and more vivid, detailed, differentiated imagery—to the point of seeing your fish’s image thrashing on your hook.
As expected with Garmin fish finders, the GPS is no less proficient. Tuned to a 5-hertz GLONASS satellite navigation network, this unit refreshes an angler’s position and bearing five times a second. Moreover, it can store up to 5,000 waypoints with precision while returning you to the next honey hole.
The 7-inch screen facilitates CHIRP clarity to the benefit of the angler’s eyes. Not only are your current routes, trails, bottom structures (especially densities) and fish easier to detect on screen, but so are the preloaded details of more than 17,000 lakes, streams and reservoirs in the U.S.—all thanks to the science of LakeVü HD mapping.
The echoMAP rounds out its pre-stored data with all the highways, freeways, backroads, bridges, camp areas, marinas and docks of popular fishing areas. A micro-SD card slot allows anglers to expand the unit’s flash memory and use several auxiliary, high-resolution drives that enhance visuals while displaying paths to fishing hotspots.
If this is not enough tech muscle for you, a Panptix port in this unit allows you to gain a view of fish activity up to 100 feet away by simply pointing your trolling motor in a chosen direction.
6) Garmin Striker 4 – Best Kayak Fish Finder
Best for: Kayakers or ice-fishing buffs who need a light, small, yet very visible unit that amply integrates GPS with sonar capacity.
- Best Fish Finder under 200 $
- Good clarity for a small screen
- Rugged and water resilient
- Swivel mount and transducer options for greater imagery and fish detection
- You will have to add about five pounds to your small craft because the unit runs on a 12-volt battery
- Some software bugs have been reported
The Garmin Striker 4 is the best cheap fish finder in our selection and rates among the most suited fish finders for a kayak or on ice.
It hints of features found in its more well-appointed big brother, the Striker 7SV, but is pared down in weight (just over 8 oz.) screen size, wattage and frequencies to meet the needs of the budget-restrained angler and those who want an easy fit for smaller craft.
It manages to blend GPS capabilities with sonar and a rugged, resilient construction, characteristic of the Editor’s pick—not to mention a split-screen zooming capacity. If you upgrade its transducer, it even employs CHIRP technology with its resulting clarity, despite the smaller 3.5-inch screen.
The Garmin Striker 4 does not scan as deep as the 7SV or the next-level Striker4DV but still effectively reads down to 1,300 feet in freshwater and 750 in saltwater. Its vertical stance lends to visibility for the paddler and provides a fairly decent picture of fish size (using the color-enhanced arc symbol).
Its built-in flasher further supports fish finding in real time as they pass beneath your kayak or inflatable fishing boat. A tilt-and-swivel mount further aids the paddler’s cause. It stores bearings and fish activity for return trips via its waypoint marker and sports a very intuitive, uncomplicated keypad to complement easy to read speed, depth, temperature and structure icons.
As mentioned, the Striker 4 comes with a few extra fish-finding steroids in the 4DV version, but at a higher price than the 4, which hovers just a tick above a hundred bucks.
7) Deeper Smart Fish Finder 3.0 – Best Portable Fish Finder
Best for: Ice fishing, high-lake fishing, kayaks or rafts and fishing from the bank.
- Very easy
- Self-contained Bluetooth connection
- Rechargeable battery
- Very compact
- Remoteness not an issue
- Like an iPhone, its battery is not easy to change
- Connection is sometimes interrupted and requires closure of other apps
- Its color could be brighter for easier visibility on the water
If you think today’s sophisticated fish finders are only for watercraft that cover a mile of water in 10 minutes, think again in the case of the portable Deeper Smart Finder 3.0.
Think of sonar ingenuity running amok, then picture yourself in a float tube or one-man raft on a 6,000-foot high mountain lake or sitting over a hole in the ice. Toss this round, disk-looking echo finder into the water and then turn on your smartphone or other handheld device to see it go to work.
Like its bigger brothers mounted on decks of wave crashers, it relays depth, temperature, bottom structure and suspended vegetation data—not to mention fish locations—in a more immediate environment, such as down to 130 feet deep. Just load its very intuitive fish finder app, compatible with most iOS and Android devices, to use this fish finder almost anywhere and in any kind of floating device.
Almost anywhere means even those remote spots miles and miles away from the nearest internet connection, all because it uses an internal Bluetooth network. Look mom, no satellites!
This is strictly a down-scanning show on two frequencies: a 15-degree cone from 290 kHz to a 55-degree cone from 90 kHz. One major caveat: All other apps on your device must be turned off to gain optimal performance from this nifty innovation that can fit inside fishing vest pocket.
Buyer’s Guide: How to Choose a Good Fish Finder
The word “sonar” alone intones something relegated only to scientists or the world’s Sheldon Coopers (of “Big Bang Theory” fame)—certainly not the hardy outdoorsman or fisherman. When dumbed down to “fish finder,” however, it becomes a little less intimidating.
That said, before shopping for one—especially for the first time—you best succumb to a brief lesson in the science of these spectacular little gems that turned commercial fishing and naval maneuvers on their respective heads when first invented in Japan some 70 years ago.
A recreational fish finder or sonar receiver can be as simple as you like—all the way down to tossing a tethered transducer over your small raft or float tube in a small lake or pond to read its signals on your smartphone, thanks to modern digital technology.
However, heftier watercraft that course large lakes, reservoirs and the sea require a hardier fish finder that detects moving objects in greater detail, in deeper water and at higher speeds. High-resolution screens, wide-ranging frequencies and rugged, waterproof housings are required.
Learn just a little about the science behind fish finders before laying down a couple hundred or more smackers for one.
Lesson 1: How they work
Sonar simply refers to sound waves from bubbles or moving creatures under water. Sound emitted from moving objects—including boats—bounces from the bottom, allowing a fish finder to differentiate between bottom (of great mass) and a suspended object (i.e., fish or weed globs of lesser mass).
The transducer reads the speed, distance, and rate at which these sound waves return to translate them in terms of depth and location related to bottom.
The technology for sonar devices or fish finders is much more refined and advanced in those utilized by military craft. The ones you mount on your boat’s deck are “Simple Simons” in comparison, but quite capable of picking up anything you might want to catch, from bluegills to sturgeon.
Transducer and its cone
Today’s sport version consists of a transducer, attached to the hull of your boat just below waterline, and a recorder in the form of an LED screen. Some with paper charts and a stylus remain in use, but most anglers prefer the type typical of those manufactured by Humminbird, Furuno, Lowrance, Garmin and Raymarine to name only a few.
Each fish finder is equipped with a specific zone or range of sound detection, called a cone. It is indicated in degrees. Some sonar receivers emit a 20-degree cone while some read sound within a 60-degree cone. Most range from 15-20 degrees.
Details are in the kHz
The volume of kilohertz or frequencies in a fish finder determines how much detail it can relay beneath the water’s surface. A high frequency translates into a shorter length of the unit’s pulse, which leads to reading finer details of objects and fish. Longer pulse lengths, characteristic of fish finders with low frequencies, limits the detail of objects detected, but allow for deeper detection. For instance, a 50kHz unit (50,000 cycles per second) can typically detect objects more than 2,000 feet deep. A 200kHz (200,000 cycles per second) unit can detect structures anywhere from 500 to 700 feet deep.
Related to its frequency is a fish finder’s power, expressed in terms of wattage. The speed in which a fish finder reads structure beneath the water depends the level of its wattage: The higher the wattage, the faster you will see results on your screen. This can prove critical, depending on whether you are anchored or trolling.
Sideways scan vs. down scan
Note that some transducers are designed to detect sound waves almost horizontally or sideways. If casting for muskie, bass or fish in shallow water, this type of fish finder excels. Some anglers even equip their boats with a side scanner as well as the traditional down scanner. This way, the angler can see fish for near-future pursuit and those for immediate pursuit.
Manufacturers are currently developing sonar units incorporating both a sideways and downward capabability. They are not yet ready for market, however.
Lesson 2: How to set up and use a Fish Finder
When you pull your unit out of the box, you will most often find it accompanied by a transducer. Some units require you to buy it separately, however.
The unit should come with a mount and screws that can be attached to your deck or a boat seat, depending on the size of your boat. On cartoppers or aluminum craft, a seat is often used to mount the unit. On a larger boat, perhaps of fiberglass, the dash or center console is used.
Power sources and interference
Some units come with a built-in power supply: either a replaceable battery or rechargeable battery. Others must be powered by a 12-24 volt battery in your boat. Try to avoid using the battery in your boat that powers your motor(s). The engine noise can wreak havoc on your fish finder signal. Therefore, install an auxiliary battery should your unit’s power source not be built in.
Also, when using your boat’s battery, make sure you are afixing the cables from the sonar unit to the battery in a way that keeps the cables out of your way. Pinning them just under the inside of your gunwale or beneath a floorboard works best to avoid tripping or other hazards.
The power cable and transducer cable should be installed separately into the unit.
Turning it off
Always remember to turn off your unit before cutting power to your boat’s electronics. Otherwise, you risk malfunctions in your fish finder. Many anglers install a manual switch to the unit’s power cable to expedite this maneuver.
Find the power button to turn on the screen. If you use a smaller craft, see how visible it appears in the position you chose to mount it. If your unit’s mount swivels and tilts, all the better. Don’t bury it in a cluster of other devices, gauges or equipment on your deck. Keep it in a place that is easy to see all data via quick glances.
If your boat lacks a covered deck or overhangs providing some shade, try to place the unit in the most sun-protected spot as possible.
For larger boats, those with dashboards, your unit’s auxiliary battery is connected to the main control panel. Your unit’s power cable should be connected to the control panel as well.
Lesson 3: What You Need to See on Your Screen
Basically, the most essential data to finding fish or at least the zones in which they most likely dwell include bottom detection, moving objects that are most likely fish, your boat speed, water temperature.
As for recorded data, a GPS capacity brings you back to the most successful fishing spots and tracks your path so that you don’t find yourself needing a human finder at sea or on gigantic lakes and reservoirs. All of these images need to be easily seen on the monitor and stored for the angler’s convenience.
Some units, as aforementioned, beef up their resolutions, screen sizes, frequencies and image details (CHIRP provides one example) to provide an extra edge for the angler.
One of the most critical readings requiring easy visibility is depth. Fishing gear and, more importantly, your boat’s hull face great peril if you are not able to quickly read the current depth and hear the unit’s sounder, indicating imminent shallows.
If you like to classify the type of bottom structure below the boat, high pixel resolutions, CHIRP and effective, accurate color application helps. It can correlate fish success to the type of bottom structure associated with such success. This aids your ability to recognize a fishy zone even though you are not yet seeing fish on your screen.
A side-scanning unit helps tremendously in this effort. Moreover, units that offer both side- and down-scanning capabilities simultaneously further your ability to navigate the boat toward fish yet to be detected on the screen.
When shopping for a fish finder, be sure to read about particular units’ backlight capacities for fishing at dawn or dusk, if not at night, and the screen’s visibility under bright sunlight.
Lesson 3: Don’t Pay More for What You Don’t Need
Know what you need in terms of fish-finding and GPS readings. Are you fishing more than 50 days a year from your craft and need to store waypoints to your most successful spots in the past? Are you fishing waters abounding in bottom structure and flotsam, requiring a finer screen resolution and CHIRP technology to discern fish from debris? Look at the higher-price-range units.
Are your needs more simplified? Are you usually moving slowly in your boat? Is a depth sounder and a fish indicator all you require? Plop a hundred or fewer dollars down for a unit that lacks all the other bells and whistles.
Consider the unit’s power source in terms of its economy as well. Will it need an auxiliary battery? Its its source built in and if so, how many batteries will it require in the span of 50-100 days of fishing per year?
How close will you be stationed to your unit while sitting in, paddling, or steering your motorized craft? This will dictate whether you need a large screen. Is your craft an open deck or kayak? Then buying a waterproof unit is worth the added expense.
Also, consider whether you want to forward data to another device at home or in your pocket for future reference while sitting down for breakfast at home or lounging in the neighborhood coffee shop. Perhaps you want to share it with an angling friend. Some of our top seven picks include wi-fi and data transfer between compatible devices. Android and iOS are usually inclusive.
Fish Finder FAQs
Which brands make the best fish finders?
New manufacturers continue to creep onto the best-fish-finder stage these days, especially as techonological advances and resulting patents emerge. That said, brands such as Garmin, which excels in GPS because of its landbound navigation legacy, competes with the best in the fish-finder industry because of its adroit adaptation to the marine world.
Lowrance continues to stand out from its early days in radar and sonar technology; Humminbird enjoys an equally rich history, but in fish-ID and bottom reading in general. Meanwhile, Raymarine also maintains a long, constantly ground-breaking existence in the fish-finder market.
As 3D and portability innovations unfold, especially in the wireless and internal Bluetooth arena, new manufacturers will surface. Already, Deeper and Vexilar are producing smart portable fish finders, some equipped with GPS receivers as well.
How important is a unit with both GPS and Sonar?
Face it. We live in an era of instant gratification, for better or worse. Most fishermen today demand GPS tracking and storage in their fish-finding units because other technology in fish-catching efficiency keeps marching on.
Better lines, lures, presentations in general must be complemented by better fish detection. It is practically expected by anglers these days. Therefore, it is worth the price to buy a unit that keeps you and your boat en route to proven hotspots and off the lost-at-sea list.
You can now buy GPS-sonar combos for a little more than $100. The exceptional models will range up to $1,000 or more.
What should come with my sonar/GPS unit?
Though some models require a separate purchase of their transducers or enhanced transducers, a transducer-inclusive unit is preferable. It usually results in easier, more streamlined installation and often saves you a few bucks. A mount, preferably one that swivels and tilts, should also come with your purchase.
If built-in software engages a trolling motor to steer to your unit’s waypoints, you may not find a manufacturer willing to include said motor in your purchase, but you should inquire as to whether said manufacturer’s own motor is best in terms of compatibility. Same goes if your unit demands a 12-volt battery as its power source. If power is built in, you should see if the battery or batteries come with the unit or whether you must buy them separately.
How long do these devices last?
This depends on the construction and waterproof qualities of a unit. If you fish a lot in saltwater, a unit without waterproof design and construction can deteriorate or malfunction over a short period—perhaps two years in some cases. That said, most of the aforementioned manufacturers offer warranties from one to two years.
For extremely expensive units, you can purchase longer warranties. In general, a fish finder of decent quality and construction should last well beyond a couple years, no matter how much you fish and where.
Keeping it covered during transport on your boat’s trailer and when sitting for long periods beneath either sun, sleet or rain also extends its longevity.
Can I store data from my fish finder to another personal device?
Yes, many fish finders come with Bluetooth capability that enables you to forward data to a personal computer, handheld or tablet at home, not to mention a fishing buddy’s device. Share the wealth of fishing tips at will.
What can cause interference with my fish finder?
Your motor can create noise that interferes with your fish finder’s ability to transmit sound waves. If you are using several electronic devices on the same battery, this may also cause interference. Keep your unit isolated from other high-powered electronics in terms of its cables and placement.
Can I use the same fish finder for shallows, deep water and on ice?
Yes, some models include side and down scanning while featuring internal power sources that allow you to set up on ice. You only need to shop around. If you already own a down-scanning unit, you might try to simply buy another unit that side-scans. The downside: packing two different units with you on the ice.
As in most electronics, the technology in fish finders, as well as GPS receivers, moves faster than a hooked bonefish. Keep reading fish finder reviews and buyer’s guides such as this one to stay abreast of the newest innovations and how they relate to the type of fishing you enjoy the most. Channel the scientist in your hook-setting soul to become a more educated sonar-unit consumer.
Image credits: all product images courtesy of the respective manufacturers