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Deeper Sonar Review: Deeper Start, Pro/Pro+, and CHIRP Reviewed

Fish finder tech has come a long way, and beyond the hull-mounted transducers and consoles common on bass boats and the like, companies like Deeper now offer tiny, portable fish finders that you can cast from the shore or mount via transom to your kayak.

Costing ten times less than traditional systems, you might be wondering if they can really make the grade.

We’ve got answers, and below, we review each of Deeper’s fish-finding line-up to see just how capable they are.


Deeper Start Review

Deeper START Smart Fish Finder - Portable Fish Finder and Depth Finder For Recreational Fishing From Dock, Shore Or Bank | Castable Deeper Fish Finder with FREE User Friendly App | Phone Compatible

Available at: | Amazon 

Maximum depth: 165 feet
Maximum range: 165 feet
Transducer beam angle: 40 degrees
Frequency: 120 kHz
Compatibility: iOS 12.0 and Android 6.0 forward
Battery life: up to 6 hours
Charging time: 2.5 hours

Deeper’s Start, as its name suggests, is a good place to begin for anglers who need a castable fish finder. And whether you work the banks of your local lake for crappie or bass or throw double-rigs from a pier for blues and specks, the Start is going to become an asset you’ll quickly come to rely on.

As with all of Deeper’s sonar systems, the Start pairs with your smartphone or tablet, and it’s compatible with both iOS and Android. Relying on a lithium polymer battery, depending on your usage, it can run for as long as 6 hours on a single 2.5-hour charge.

Be aware that the Start’s maximum range is dependent on your device’s antenna; the better it is, the longer the maximum operating distance. And though you can get as much as 6 hours of battery life, in the real world, expect a bit less than that for most users.

In “simple” mode, the screen is very easy to read for even novice users.

So what does the Start do for you?

Quite a bit!

Not only will it give you essential information like water depth and temperature, but you’ll also see the contour of the bottom, vegetation, and icons denoting three sizes of fish as well as their relative depth.

That’s critical information for any angler, as understanding where to find cover and structure is step one in finding fish. 

The screen that the Deeper app uses is simple to read, uncluttered, and ideal for occasional anglers who just want a better idea of structure, cover, and fish location, especially on it’s “simple” setting.

On the “detailed” setting, expect something more akin to a traditional fish finder, with more information about the bottom composition as well as depths for each fish it locates.

It’s hard to argue that the Start isn’t a step forward for anglers who can’t rely on traditional fish finders!

That said, Deeper isn’t revealing an important technical spec we’d like to know: target separation. This matters, especially as it impacts fish finding performance.

Low target separation, for instance, makes it more likely that a few small fish close together will register as a large fish to the sonar, and this is certainly an issue for the Start. My guess is that target separation is poor, allowing a few minnows to register as a real fish.

That’s not a deal-breaker to my mind, especially for the price.

It’s also worth noting that the Start’s app lets you track locations and make notes, enabling you to mark hot spots and record things like which lures and techniques were working.

That’s a cool feature that really can tilt the odds in your favor.

And I can tell you that once you try the Start, you’ll be hooked!


  • Easy to use
  • Uncomplicated interface makes the Start easy to read and understand
  • Very inexpensive for the tech you get
  • Good battery life and recharging rate
  • Pretty good fish-finding tech


  • Target separation is poor, leading to fish finding inaccuracies
  • Maximum range can be dramatically shorter than 165 feet

Deeper Pro and Pro+ Review

Deeper PRO Smart Sonar Castable and Portable Smart Sonar WiFi Fish Finder for Kayaks and Boats on Shore Ice Fishing Fish Finder

Available at: | Amazon 

Deeper PRO+ Smart Sonar Castable and Portable WiFi Fish Finder with Gps for Kayaks and Boats on Shore Ice Fishing Fish Finder

Available at: | Amazon 

Maximum depth: 260 feet
Maximum range: 330 feet
Transducer beam angle: 15 and 55 degrees
Frequency: 90 kHz and 290 kHz
Target separation: 1”
Compatibility: iOS 12.0 and Android 6.0 forward
Battery life: up to 6 hours
Charging time: 2 hours

For anglers who hit the water more regularly, Deeper’s Pro and Pro+ are better buys than the Start, offering vastly expanded capacity.

An easy-to-use menu allows you to adjust sensitivity as well as frequency, enabling you to switch between a relatively high frequency (290 kHz), which gives more detailed information about what’s in the water column, and a relatively low frequency (90 kHz) that penetrates deeper water more easily.

The low frequency is paired with a wider beam angle as well, offering a bigger view of the bottom. Ideal for scanning large areas, the idea is to switch to the higher frequency to pinpoint fish locations.

The Pro series sports a more powerful transducer and transmitter, extending the depth and maximum range of these devices. Frankly, that’s not a huge selling point for most anglers--most of us don’t fish that deep, and those of us who do probably use a boat and standard fish finder. 

But I’m not knocking the improvement; it’s just not the real reason to upgrade.

Instead, it’s a host of features like GPS (on the Pro+), detailed mapping options, fine-grained target separation, and kayak and ice fishing capabilities that give flashers and traditional fish finders a real run for their money.

The bottom line: most anglers would probably be well-served to consider the Pro or Pro+!

Let’s give each of these features a closer look.

The GPS system on the Pro+ enables sophisticated bathymetric mapping of the bottom, and whether you do that by casting this unit from shore or running it from an available after-market mount on your kayak, canoe, or Jon boat, you’ll quickly discover every hollow, point, hump, and brush pile in your local lake.

That can be the difference between catching or coming home empty-handed, and it’s pretty amazing in a tiny, portable device offered at this price. When paired with an optional app--Fish Deeper--the utility of your maps increases exponentially, and this is truly an amazing option for serious anglers.

The Deeper Pro and Pro+ know their audience, and the interface--while being easy to use and uncomplicated to read--provides data like a standard fishfinder. With just 1 inch of target specification, it can tell the difference between schools of bait and fish, offering the precision that serious anglers crave in their electronics.

For ice fishing, I’m completely won over by the Pro and Pro+!

You’re already lugging a bunch of heavy gear onto the ice, and I love the small size and light weight of these units. Just drop them in a hole and go--that’s the promise--and with the traditional flasher or fish finder screens available, whatever your preference, you’ll be fishing more or less instantly.

Where the big difference appears for me is the ease of use.

For instance, when I’m working a bunch of different holes to decide which to fish, it’s very easy to move, drop, read, and move again with the Pro and Pro+. That’s a big deal--as you’ll know if you’ve ever done this.

And when a fish is on, there’s no wire and transducer to worry about--just fight the fish like the Pro isn’t there!

No hassles--no worries.

I didn’t expect to like the Deeper Pro series as much as I do. It’s a game changer relative to the expense of traditional fish finders, especially for small boat anglers.


  • Easy to use
  • Uncomplicated interface makes the Pro and Pro+ easy to read and understand
  • Very inexpensive for the tech you get
  • Good battery life and recharging rate
  • Awesome fishing tech for ice and small boats
  • Excellent target separation


  • PRO model can only create depth (contour) maps while trolling with boats or kayaks

Deeper CHIRP Review

Deeper Chirp Smart Sonar Castable and Portable WiFi Fish Finder for Kayaks and Boats and on Shore Ice Fishing Wireless Fishfinder

Available at: | Amazon 

Maximum depth: 330 feet
Maximum range: 330 feet
Transducer beam angle: 7, 16, and 47 degrees
Frequency: 100 kHz, 290 kHz, and 675 kHz
Target separation: .4”
Compatibility: iOS 12.0 and Android 6.0 forward
Battery life: up to 8 hours
Charging time: 75 minutes

Take the Pro+, further improve the transducer, add awesome CHIRP sonar tech, give it a better battery, and decrease the target separation to less than a half-inch, and you get the unbeatable Deeper CHIRP.

Let’s get right down to it.

The CHIRP has a depth of 330 feet, brought to you by a more powerful transducer rather than an ultra-low frequency. For deep lakes, that can be a real advantage, but it’s hardly the selling point of this excellent system.

Instead, it’s the CHIRP sonar for which it’s named, running through the frequency bands to provide more information than traditional systems. CHIRP by itself is a game-changing upgrade, but add to that target separation of less and an inch, and you get fish finding excellence that competes with name-brand traditional systems like Humminbird, Garmin, and Lowrance.

That, plus a battery that charges faster and lasts longer separates the CHIRP from the Pro+, making this a worthy upgrade over that already capable option.

At this price-point, the Deeper CHIRP is ridiculously good.


  • Easy to use
  • Uncomplicated interface makes the CHIRP easy to read and understand
  • Very inexpensive for the tech you get
  • Awesome battery life and recharging rate
  • Awesome fishing tech for ice and small boats
  • Amazing target separation
  • CHIRP sonar is the best in the business
  • Can create depth (contour) maps while trolling with a boat or kayak.
  • 5 year manufacturers warranty


  • ???

Fish Finder Basics: Frequency Demystified

Sonar is just sound. It’s beyond the range of human hearing, but in principle, no different than any other noise.

Sound takes the form of a wave, with crests and troughs or peaks and valleys. Higher frequencies pack more of these oscillations into a given span of time than do lower frequencies. 

frequency of sound waves

Low frequencies - penetrate water better than high frequencies. Fish finders with very low-frequency transducers can “see” through the water better, allowing them greater depth.

The weakness of low frequencies, however, is that every oscillation provides data, and with less crests and troughs per second, they can’t provide as much information as high frequencies.

Think about your mobile phone for a second. It works much the same way, which is why 4G can carry more information--more data per second--than 3G. Higher frequencies equal more information.

High frequencies - offer greater detail, allowing your fish finder to “find” fish and tell you their size and location.

They can’t penetrate much water, however, and they can’t tell you much about the bottom, including details like structure and cover.

Dual sonar - Most fish finders use dual frequencies, pairing a high and low frequency to provide the best features of both. For instance, when you see a fish finder that lists two frequencies, such as 77/200 kHz, that means that its transducer broadcasts at both 77 kHz and 200 kHz simultaneously.

The low-frequency signal reads the bottom, while the high frequency finds the fish.

Fish Finder Basics: Sonar Pings or CHIRPs

“One ping only, please.”

The Red October’s sonar used “pings,” bursts or pulses of noise that it sent into the water, striking objects and returning to its transducer for analysis. When the sonar was active, it wasn’t constantly transmitting sound.

Most fish finders aren’t much different. They use dual frequencies in pulses: short “pings” like the one you heard in the video. These short pulses are transmitted together, providing enough data to give the fish finder’s electronics a picture of the bottom and anything suspended in the water column.

But military tech has advanced a long way from the Cold War, and modern sonar systems use something called CHIRP, or Compressed High-Intensity Radiated Pulse.

CHIRP sonar uses much longer pulses than standard systems, starting at the low frequency and moving quickly to the high frequency. These longer bursts, and the range of frequencies between the lowest and highest, provide much more information than standard sonar systems.

traditional vs chirp

As you can see, there are many more peaks and valleys in the CHIRP signal, and each and every one carries information. The military uses CHIRP sonar because it’s simply far more effective than dual frequency sonar, and the good news is that so can you!

Some fish finders now offer CHIRP sonar. It provides better imaging, greater accuracy, and more information.

This isn’t a marketing ploy--it’s real, it’s a fact, and in our opinion, it’s worth paying for.

What We Consider When Selecting a Fish Finder

Obviously, we prefer CHIRP sonar systems. But what else matters?

Target Separation

Target separation is simply a measure of how precise the fish finder’s sonar is at distinguishing individual fish from one another. Smaller numbers mean better performance.

Transducer Beam Angle

Often a selling point, this is not nearly as important as marketing leads you to believe.

All other things being equal:

Wider angles let you see a greater area below your transducer.

But, and this is a big but, the “specified cone” isn’t the actual area the fish finder reads. Instead, it’s shaped more like this:

tranducer beam angle

Moreover, for a specified beam width, the structure of the bottom can greatly affect performance. And the greater that width, the more likely this problem is.

transducer beam width

As a general rule, the shallower the water you fish, the wider the transducer beam angle you want. Too much will create problems, and if you fish in deeper water, you want a tighter, more focused beam angle.

Final Thoughts

I wasn’t won over by Deeper’s first foray into the fish-finding market, but they’ve got me hooked now.

Light, portable, easy to use, and ultra-capable: that’s what the Deeper line-up promises--and it’s clear they deliver!

Whether you fish from a kayak, work the hard water from a hut, or cast from shore, Deeper’s products will improve your chances of the catch of a lifetime.

About The Author
Pete Danylewycz
Born and raised in Cleveland, Ohio, Pete grew up fishing on the Great Lakes. Whether he's casting a line in a quiet freshwater stream or battling a monster bass, fishing is his true passion.