Deeper Pro and Pro Plus Fish Finder Review – Wireless In The Water


The Deeper Pro castable fish finder from Deeper UAB (Lithuania) is primarily intended for quick, on-the-move fishing trips. You can attach the wireless castable Deeper Pro to your rod while fishing from the bank, your boat or kayak, bridges, or wherever else you’ve found your favorite hotspot. With the Deeper, you can immediately improve your chances of making a catch.

The Deeper is also perfect for those who favor urban fishing. Especially when you’re fishing in the city and standing shoulder to shoulder with other anglers, a portable and castable fish finder like the Deeper can really put you ahead of the pack. You can even use the Deeper when you’re ice fishing during the coldest times of the year. In the following comprehensive Deeper review, we go in-depth on the use and functionality of this portable fish finder. We’ll start with the most important aspect: at a price of over €200/ USD200, the Deeper isn’t exactly at throw-away item.

How can you ensure that you don’t lose your portable, wireless Deeper sonar?

You can attach the Deeper Pro fish finder directly to your fishing line – or to a carabiner and leader line – using one of its 3 small, threaded eyelets. So far, so good. The Deeper weighs about 100 grams, which means you’ll need to use a robust rod, line and knots to make sure the Deeper doesn’t go flying off in the wrong direction at some point.

Again, don’t skimp on the line and the right knots for the job! It should go without saying that a loss of over €|USD 200 would be both unfortunate and frustrating (unfortunately, we speak from experience). Here are a few tips on how to avoid losing your Deeper castable sonar:

  • A proper rod, rated for predatory fish or carp (approx. 3 oz (80 g) and higher)
  • Fishing line with at least 22 lb (10 kg) (ideally more) break strength
  • Proper knotting with very tight knots


And now the most important tip of all: Set your brake as lightly as you can while still ensuring the Deeper doesn’t unspool any line when your rod is outstretched with the brake engaged. With your brake set up this way, you drastically reduce the chances of losing your Deeper.

User recommendations

Here’s some advice from Andreas Zachbauer: To avoid losing your transducer, attach it to a 1 meter-long leader line with 66 lb (30 kg) break strength. Attach the Deeper to one end and a small, load-bearing fixed float to the other. Then, if your leader line happens to break away on account of a cast or a snag, you can use a backup rod and wobbler to aim for the length between the fixed float and the Deeper Pro. If only your hook or weights get hung up, you can simply reel in the leader line. The result: your Deeper is saved!


“What can a depth finder really do?” The ultimate webinar of “how to catch more fish with the deeper” is coming soon.

Where can you use the Deeper?

It’s important to understand the fundamentals of fish finder functionality if you want to get the most out of your Deeper. Every Deeper user should know what’s going on in their sonar cone!

The Deeper sends soundwaves downward and collects their reflected echoes. The intensity and duration of the echoes is measured and transmitted from the Deeper to your smartphone or tablet. The Deeper app then analyzes this data in order to display it graphically on-screen. The user (you) can then see and interpret what is going on underwater. You can discern bathymetric features such as plants and undergrowth; individual fish – and schools – are also displayed. The special thing about depth finders is that they can give you a good idea of ground density (second and third bottom echoes).

Display size

The Deeper app offers detailed readouts on your smartphone or tablet and allows you to make the most of your display size. This is the most important benefit of the Deeper as compared to other fish finders /depth finders in this price segment, which often have only a small display and aren’t even portable! For rivers and lakes in Germany, the Deeper’s transmission output is more than sufficient. You can also update its software to utilize any new features and functions that the manufacturer releases. There’s even a beta test of the newest software going on right now!

Deeper technical details

The Deeper portable fish finder supports two different transduction cones: you can choose between 90 kHz and 290 kHz frequencies. Don’t confuse this selectability with dual-beam technology (which transmits and displays both frequencies simultaneously). With the Deeper, you can view one frequency or the other at any given time. The 290 kHz frequency is transmitted at a 15° aperture angle, which creates an ideally narrow transduction cone for distinguishing even moderate depressions in the bottom. In our view, the 90 kHz frequency with a 55° aperture angle is completely superfluous – at a depth of 16 feet (5 meters), the transduction cone has a diameter of nearly 20 feet (6 meters). Practically speaking, this means that smaller holes in the bottom won’t be recognized or displayed. Really, those holes are where a good deal of the fish like to hang out (see our book “The Ultimate Fish Finder Guide”).

When should you use the 290 kHz frequency?

If you’re fishing at depths of up to 66 feet (20 meters )and casting out between 33 and 100 feet (10 and 30 meters), go with the 290 kHz option on your Deeper. The frequency results in a detailed image, and at a depth of 66 feet (20 meters), its 15° aperture angle produces a transduction cone with a diameter of 16 ft (5 meters). At a depth of 33 feet (10 meters), you’ll have imaging from a cone with a diameter of 8 ft (2.5 m) – if you’re not underway as quickly as you would be with a boat, that’s totally fine! If you cast the Deeper out several times in succession, you can get a good picture of how things look underwater and recognize things like drop-offs, brush and other submerged obstacles.

The narrow aperture angle at 290 kHz is also ideal for the Deeper’s bathymetric mapping feature – it scans the various, small changes in the bottom that the larger aperture angle at 90 kHz just can’t catch.

When is a 90 kHz frequency best?

Choosing a 90 kHz transduction cone entails an aperture angle of 55°. At a depth of  66 feet (20 meters), this results in a cone width of just under 72 feet (22 meters) being displayed on your smartphone. This can be worthwhile for viewing fish arches in the app, but you can pretty much forget usable bathymetry at this frequency – the scanned area is simply too large. In very shallow waters (3 – 10 feet / 1-3 meters), you can use the wide aperture angle to display as many fish arches as possible and determine whether a given location has enough fish to qualify as a hotspot.

The 90 kHz frequency has a much longer wavelength than that of 290 kHz, which means that smaller fish can no longer be reliably scanned and displayed. Fish-to-fish spacing also has to be fairly wide in order to identify individual fish. In short, you lose a lot of details when you use 90 kHz!


At long last, Friday Lab’s development phase is over. In addition to the classic Deeper, there’s now the Deeper Pro and the Deeper Pro Plus. The two new Deeper fish finders have brought a few welcome changes along to the party.

What distinguishes the new Deeper fish finder models?

The much-criticized Bluetooth connectivity has met a much-welcomed end. Effective immediately, both of the new Deeper depth finders operate via Wi-Fi. The Wi-Fi signal is significantly stronger than that of Bluetooth, which means that even submerging the Deeper won’t interrupt the transmission. According to the manufacturer, the new models have an effective range of up to 330 feet (100 meters). Would anyone ever want or be able to cast their $300 portable depth finder out to 330 feet (100 meters)? We’re more than a little skeptical. Up to 5 friends can make connect to the Deeper and display the incoming information on their phones.

Changes from previous model 

The transducer’s scanning frequency has also undergone a change. The Wi-Fi depth finders transmit their signal 15 times per second – that’s twice as often as the classic Deeper. Not only can they transmit at depths of up to 260 feet (80 meters), but the resulting transduction cone also provides a much greater level of detail. If you’re fishing from the banks, you’ll never miss out on useful info again. The Deeper Pro Plus depth finder also boasts GPS functionality. Time will tell to what degree this feature drains your battery. It’s probably a good idea to bring an external battery pack to recharge on the fly. Incidentally, our highest recommendation goes to the GPS-equipped model. The mapping feature is a game-changer!

Deeper series overview

  • Bluetooth-only is dead in the water – Deeper 3.0 (Third iteration of the Bluetooth model)
  • For those who don’t want or need mapping – Deeper Pro (Wi-Fi)
  • Our favorite – Deeper Pro Plus (Wi-Fi and GPS)

The Deeper portable fish finder offered by the Lithuanian company DEEPER UAB has grown to be a favorite since its introduction in Europe in 2013, giving the company an impressive degree of market penetration in a relatively short time. There are now various accessories available for the portable sonar, and the 3 threaded attachment points offer a lot of flexibility. For example, you can even screw a glow stick holder or a float into the eyelets, which can also be used to permanently mount the Deeper to your boat.

Another accessory would be the smart phone armband – you can attach it to your forearm to make sure that you can keep an eye on the display while reeling in your catch (and never miss another fish)! We’ve saved you some work by researching affordable and – more importantly – narrow armbands.


 The Deeper Pro Plus: A year in review – Still sublime or slowly sobering?

Deeper software/app

The app features a fishing calendar that shows which fish are in season at any given time of year. You can use your camera to make notes on your favorite hotspots and store details directly in the Deeper notebook (you can take photos directly in the app). There is also a mapping feature with which you can view fishing supply stores, fishing spots, slips and parking lots. You can save your POIs (points of interest) in the app, as well. Imagine you’ve just found a hotspot. The app will establish your location and ask if you want to save the hotspot. You can add a few notes like the time of day or current temperature; after a while, you’ll have created a nice databank of your favorite fishing spots. Tip: The app is pretty useful, even separately from the Deeper fish finder. It makes sure that you have all your saved information at the ready.

As opposed to other portable fish finders and depth finders, with the Deeper you only have to carry the transduction sphere as an extra, because you’ll almost certainly have your smartphone with you at all times. Especially for catching predatory fish – for which you want to carry as little weight as possible – the Deeper offers a significant benefit over other portable depth finders (such as the Humminbird Smartcast Wireless Sonar).

The app also has integrated social network buttons for Facebook, Twitter and Google+. This is ideal for posting that gigantic catch you just landed. On the other hand, if you’re the kind of angler who prefers not to give away the secrets of their favorite hotspots, this feature may be of limited use. In that case, the normal methods of bragging to your friends should suffice: snap a picture and then fire up Facebook or Whatsapp to share it.

Weather forecast

The weather forecast is set up to display a 5-day rundown. This feature is enough to get a quick overview of conditions, but if you want an hour-by-hour breakdown, we recommend using WeatherPro – the app allows you to better anticipate fluctuations in the weather during your fishing trip.

In any case, you need an active internet connection to use the weather, social, and mapping features while out on the water.

Vertical flasher

You can set up a vertical flasher using the Deeper’s software. It appears on the right side of your smart phone screen and indicates the depth and intensity of the returning sonar signal. In our view, this is one of the most important features offered, as it helps you to determine what is going on in the transduction cone at any given time.


The ability to create bathymetric maps is easily the Deeper’s best feature. The function allows you to produce maps of your chosen body of water or hotspot, complete with depth lines (at 0.5 meter spacing). You’ll always know where it’s worth spending your time. Again, the feature clearly displays holes, depressions, and underwater hills – you can even save them to the cloud for later reference. With the ability to recognize every edge on a jetty, you can count on better chances of catching walleye. For the first time, land-based anglers have access to a feature that was previously only available to those who have the privilege of owning a boat.

Navionics offers this functionality with SonarChart for GPS-enabled depth finders. You can find the map right here on our site. The Deeper’s mapping feature is pretty good for anyone just getting into the world of depth finders. However, for a portable fish finder, it’s amazing.

Here, you can download the Deeper software to your smartphone and try out all the available features for free. To do so, open the app and go to the  “settings” menu in the top right corner of the screen. Scroll all the way to the bottom and select “start simulation” to get a picture of the kind of details that the unit can offer. Exciting stuff, no?

Smart Imaging

In terms of processing power, today’s smartphones are far-and-away better than the depth finders available on the market. However, a depth finder/fish finder is only as good as its software. The Deeper’s Smart Imaging feature transforms the data from the depth finder into graphical representations of underwater plants (displayed as green areas), fish arches or fish symbols, entire schools, and a pretty intuitive grey line for the bottom. If you have a strong secondary bottom echo, you know that the ground is particularly hard. Translation: ideal walleye territory. Unfortunately (and we mean really unfortunately), the Deeper doesn’t handle this aspect all that well.

The depth readout

The depth readout on the Deeper isn’t adjustable, which means that important info about the bottom remains hidden. In our opinion, the Deeper team has some catching up to do, and quick – anglers urgently need this feature in order to get an accurate picture of the waters in which they’re fishing. The basic function of Smart Imaging is pretty useless, as it removes all the relevant information and leaves only fish symbols behind. The entire scope of details about the bottom or fish arches is gone!

Here’s another tip for muddy waters (like those of the Elbe and Rhine): lower the sensitivity of your Deeper to make it ignore floating particles and display only stronger echoes. You’ll always find what is currently directly under the Deeper displayed on the right side of the screen. The image then progresses to the left. Note: Because you’re going to cast the Deeper out and then reel it back in – and your smartphone will be held out in landscape format in front of you – it can be easy to forget that the images displayed on the left side of the screen actually depict the things that are farther away from you (as opposed to what is to your left). Honestly, there were occasional misunderstandings around here. Don’t sweat it.

Deeper accessories

Currently, the manufacturer of the Deeper offers a number of accessories that are actually pretty useful.

Cover for nighttime use

This little cover makes it easier to spot the Deeper in the dark or during use in rougher waters. It’s available in green, neon green, and orange. The covers are swappable, so you can adapt the unit to pretty much any visibility conditions. The top portion is easy to remove and replace, and you can even attach a glowstick.

Deeper boat mount

In our view, the Deeper shouldn’t be mounted to a boat. The software has certainly gotten better at analyzing the fish finder’s sonar signal, but the fact is that the Deeper is and will remain a primarily rod-based depth finder. However, if you only go fishing by boat a few times a year and already have the Deeper in your gear bag, you might want to pick up the boat mount. That is, as long as the waters are calm and you’re willing to go very, very slowly. The mount is fairly practical and can be attached to any bathing platform. Before you pull the trigger on the purchase, be sure to look at exactly how the mount can be attached. The Deeper is supposed to be mounted directly at the waterline – there are generally no attachment points at that height other than a bathing platform, which not every boat has.

On the other hand, the mount is just about perfect for canoes/kayaks and flat-bottomed boats!

2018 Summary

For land-based anglers, the Deeper Pro Plus portable and castable fish finder is an absolute winner, as it gives you a detailed picture of the world underwater which was unavailable up until now. The models with Bluetooth connectivity offer a range of between 65 and 130 feet (20 and 40 meters). However, we recommend giving Bluetooth a pass and going straight for a Wi-Fi model: the Deeper Pro fish finder models leave little to be desired. In our opinion, the Deeper is an ideal companion for anyone fishing from the banks. It’s also great for urban fishing, as it gives you an edge over the other anglers you’re crowded in with. Especially when fishing for walleye (which requires frequent changes of location), the depth finder is indispensable for upping your chances of a catch.

Other functions of the Deeper app:

  • Depth alarm on/off
  • Fish alarm on/off
  • Fish depth on/off
  • Ice fishing on/off
  • Vertical flasher on/off
  • Night mode on/off
  • Vertical flasher (yes)
  • Progress 5 min, 10 min, 15 min
  • Brightness 10% to 100% (lower saves battery)
  • Water temperature – especially important in spring
  • Deeper’s remaining battery level as a percentage

Caring for your Deeper portable fish finder

Be sure to check all seals on the Deeper before each use. If you find any cracks or other breaches, pack your unit back up and swap out the seal(s) when you get home. If any water gets into the Deeper, it’s game over. After each use, clean the Deeper by rinsing it with clean water. Especially in salty or muddy waters (like the Elbe or Rhine), you shouldn’t skip this step! The night before you plan to go fishing, be sure to charge the transducer (unless you want a healthy dose of annoyance the next day). You’ll have to charge the Deeper at least every 3 to 5 months, even if it hasn’t been used. This is easy to forget during the winter months, but it’s important because keeping the battery charged extends its usable life.

Technical details of the Deeper portable fish finder

  • Weight: 3,5 oz (100 g)
  • Diameter: 3,5 6 inch (65 mm)
  • Max. depth: 260 ft (80 m)
  • Range (Wi-Fi): up to 330 ft (100 m)
  • Usable in salt and fresh water
  • Operating temperature: -4°F to 100°F (-20°C to +40°C)
  • Battery life: up to 6 hours
  • Charging time: 2 hours
  • Battery: rechargeable lithium ion, 3.7V, 850 mAh
  • 2 Frequency transducers: 15° at 290 kHz (narrow transduction cone); 55° at 90 kHz (wide transduction cone)
  • Operating system and firmware update for app: iOS 5.0 and newer, Android 2.3 and newer

Deeper fish finder package contents

  • Neoprene case
  • Threaded eyelets (3)
  • USB charging cable
  • 12V USB car charger
  • 120V wall charger
  • Deeper portable fish finder w/battery
  • Download the app in advance to make sure that your smartphone is compatible!
  • Compatible with iPhone 6 and iPhone 6 Plus, iPhone 5S, iPhone 5C, iPhone 5, iPhone 4S, iPhone 4, iPhone 3GS
  • Compatible with iPad Air 2, iPad Air, iPad mini with Retina, iPad Gen. 4, iPad mini, iPad Gen. 3, iPad 2, iPad
  • Available for download: iOS app and Android app

Deeper Pro and Pro Plus accessoires:

Read more here:

Further fish finder reviews

Fish finder tips


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