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Fish finders · Castable sonar · Our take
Deeper CHIRP+ 4 Smart Sonar
Smart sonar for carp and coarse fishing
A compact castable sonar with CHIRP detail, mapping smarts and a surprisingly serious range. Handy for locating carp and coarse fish when you’re trying to make every cast count.
- Three sonar beams: 100 kHz/47°, 240 kHz/20° and 675 kHz/7°.
- Scans at up to 15 times per second, with a maximum scanning depth of 100 m and a minimum of 0.15 m.
- Wi-Fi connection works at up to 120 m and doesn’t need internet access.
- Built-in GNSS supports GPS, GLONASS, Galileo, BeiDou and QZSS for mapping and location work.
Make sure it’s the right one. This review covers the Deeper CHIRP+ 4 Smart Sonar, including its supplied hard case, night cover, USB-C cable and attachment bolts.
Tackle Index Score
Tackle Index score
A high-quality, feature-packed sonar for anglers who’ll genuinely use the mapping and beam options.
Desk-research score from specs, price and fishing fit · How we score
- Product Quality9.7/10
- Performance9.8/10
- Impact on Fish Catching9/10
- Ease of Use8.3/10
- Value for Money8.6/10
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Who it suits
Is it right for you?
Great for
- Carp anglers exploring unfamiliar lakes and pits. You can build a much clearer picture of depth changes, bars, holes and weed before settling on a spot.
- Coarse anglers who like to fish accurately. The different beam widths help with broad searching and then narrowing down a feature or feeding area.
Maybe skip if
- Anglers who only fish very familiar short-session pegs. If you already know every depth and feature, the extra information may not justify carrying another gadget.
- Anyone wanting a completely faff-free setup. You’ll need to connect a phone or tablet, interpret the display and spend time learning what the returns mean.
The lowdown
Introducing the Deeper CHIRP+ 4 Smart Sonar
A compact castable sonar with CHIRP detail, mapping smarts and a surprisingly serious range. Handy for locating carp and coarse fish when you’re trying to make every cast count.
- Three sonar beams: 100 kHz/47°, 240 kHz/20° and 675 kHz/7°.
- Scans at up to 15 times per second, with a maximum scanning depth of 100 m and a minimum of 0.15 m.
- Wi-Fi connection works at up to 120 m and doesn’t need internet access.
- Built-in GNSS supports GPS, GLONASS, Galileo, BeiDou and QZSS for mapping and location work.
Quick verdict
Verdict
The Deeper CHIRP+ 4 is a cracking bit of kit for anglers who want more information than a marker float can give. Its three sonar beams cover broad searching, tighter feature work and detailed looks at a chosen spot, while the built-in GNSS adds proper mapping potential.
It’s not essential tackle for every short session, and you’ll need a phone or tablet to get the most from it. But for watercraft, feature finding and building a clearer picture of unfamiliar venues, this is a very capable tool that should make your time on the bank more productive.
A high-quality, feature-packed sonar for anglers who’ll genuinely use the mapping and beam options.
Desk-research score from specs, price and fishing fit · How we score
- Product Quality
- 9.7/10
- Performance
- 9.8/10
- Impact on Fish Catching
- 9/10
- Ease of Use
- 8.3/10
- Value for Money
- 8.6/10
The compact ABS unit, hard case, night cover and tidy accessory bundle feel well suited to regular bank use.
Three beam options, up to 15 scans per second and a broad stated depth range give it serious searching ability.
Better knowledge of depth, bottom changes and features can lead to more accurate decisions, though it still depends on your watercraft.
The wireless setup is convenient, but learning to read sonar returns and use the mapping properly takes some time.
It’s a sizeable outlay, but the combination of CHIRP detail, GNSS mapping and long battery life makes it worthwhile for regular users.
Head to head
How it stacks up
Side by side with the closest kit we've reviewed. This updates as we add more reviews.
Deeper
Deeper CHIRP+ 4 Smart Sonar (this one)
Top scorer
Top scorer
Scores are our own, out of 10. Best in each row is in green. Prices change, so check the latest before you buy.
The full rundown
Everything you'll want to know about the Deeper CHIRP+ 4 Smart Sonar
There’s a fair bit of guesswork involved in fishing a new lake. You plumb around, drag a lead back, watch the marker and try to build a picture in your head. Sometimes you nail it. Other times you’ve found what feels like a lovely spot, only to spend a night blanking over a bit of naff bottom.
That’s where the Deeper CHIRP+ 4 Smart Sonar comes in. It’s a small castable sonar designed to give you a proper look beneath the surface. You cast it out, bring it back or work it around an area, and view the information on a phone or tablet over Wi-Fi. No internet connection is needed, which is spot on for remote venues.
The unit itself is properly compact. It weighs 94 g and measures 64 × 67 × 67 mm, so it won’t eat up much room in the tackle bag. The ABS body comes in a brown and green colourway, and the supplied hard case is a welcome touch when you’re chucking it in with leads, bait and all the usual bank gear.
The headline feature is the CHIRP sonar system. You get three beams: a wide 100 kHz beam at 47 degrees, a mid-range 240 kHz beam at 20 degrees and a tight 675 kHz beam at 7 degrees. In plain English, that gives you different ways to search. Go wide to understand an area, then narrow things down when a bar, hole or likely patrol line starts looking interesting.
That’s useful for carp work, where being a few feet out can make a massive difference. A broad sweep might show a shallow shelf running into deeper water. The tighter beam can then help you examine that transition more closely. It won’t put a bait in the carp’s mouth for you, obviously, but it can help you stop chucking into the wrong bit of the lake.
The scan rate is up to 15 scans per second, so the display can keep updating as the sonar moves. The stated depth range runs from 0.15 metres down to 100 metres. You’re unlikely to need anything like 100 metres on most coarse fisheries, but the low minimum depth is handy when you’re checking margins, shallow shelves and summer patrol routes.
Range is generous too, with a connection distance of up to 120 metres. That gives you room to search without having to stand right on the edge like a meerkat. Just remember that actual performance can be affected by your casting position, the water, obstructions and how you’re holding the phone.
The built-in GNSS is another big reason this model stands out. It supports GPS, GLONASS, Galileo, BeiDou and QZSS, giving the mapping side of the unit plenty to work with. For an angler who likes marking productive areas, recording contours and coming back to repeat a line, that could be proper useful.
Power shouldn’t be a major worry during a normal session. The rechargeable 3.8 V lithium-ion polymer battery has a typical 1300 mAh capacity and is rated for up to 15 hours. You also get USB-C charging, a night cover, attachment bolts and the hard case in the box. For serious feature finding, this is a smart bit of kit rather than a cheeky gadget bought on a whim.
Specifications
The nuts and bolts
- Material
- ABS
- Weight and dimensions
- 94 g; 64 × 67 × 67 mm
- Scanning depth
- 0.15 m minimum to 100 m maximum
- Sonar beams
- 100 kHz/47°, 240 kHz/20° and 675 kHz/7°
- Connection and battery
- 2.4 GHz Wi-Fi, up to 120 m; 3.8 V 1300 mAh typical rechargeable lithium-ion polymer battery
- Included
- Sonar, hard case, night cover, USB-C charging cable and attachment bolts
Specs checked with Deeper, Oct 2026.
Spot a model or spec change?
Our take
The smart way to find a swim
The CHIRP+ 4 isn’t just about spotting a big arch on a screen. Used properly, it helps you understand depth, bottom shape, weed, drop-offs and likely patrol routes before you commit the rods.
That makes it especially interesting for carp and coarse anglers fishing new lakes, big pits and tricky day-ticket waters. You can scan from the bank, cast it around likely areas and use the information to decide where to put the bait rather than simply hoping the spot looks right.
What you’re buying
A tiny sonar with plenty going on
The CHIRP+ 4 is built around choice. The wide 100 kHz beam helps you search a bigger patch of water, the 240 kHz beam gives a more balanced view, and the narrow 675 kHz beam lets you focus on a smaller target. That’s useful when you’re moving from general lake reading to a specific bar, margin shelf or drop-off.
It connects to a phone or tablet over 2.4 GHz Wi-Fi, with no internet needed. The built-in GNSS adds location information for mapping and repeatable work. You can use the unit as part of a proper prep routine: scan, identify a feature, mark it, then clip up and fish it accurately.
The package is nicely sorted for the bank. Alongside the sonar, you get a hard case, night cover, USB-C charging cable and attachment bolts. The body is ABS, weighs 94 g and is small enough to slip into a side pocket without turning your loadout into a tackle-shop display.
Worth knowing. The sonar tells you what’s beneath the unit, not magically what every fish in the lake is doing. Read it alongside depth, weather, water temperature, visible signs and your own watercraft. Used as one piece of the puzzle, it’s much more useful than treating the screen like a guaranteed bite alarm.
Where it earns its keep
Best for finding the right water
This is a strong fit for carp anglers tackling new venues, especially larger lakes where plumbing every area takes ages. A few well-chosen casts can show you where the depth changes, where weed starts and whether a promising-looking area actually has a clean spot worth presenting on.
Coarse anglers can get plenty from it too. On a canal, gravel pit or stillwater, the broad beam can help search around a swim, while the narrow beam is useful when you want to inspect a particular line. Match anglers and specimen hunters alike may appreciate having more confidence in what lies beneath the float or feeder line.
It’s less compelling if you fish the same small venue every week and know the productive spots like the back of your hand. It’s also not the best choice for anyone who hates phones, menus and a bit of learning. There’s no shame in that, mate; a marker float is still a cracking tool when you know how to use it.
The practical stuff
A few things you’ll want to know
For a normal session, charge it before leaving home, keep the phone secure and start with wider scans. Once you understand the general layout, switch to a tighter beam and work out exactly where you want the rig. That saves you wasting time chucking around blindly.
The up-to-120-metre connection range gives you plenty of reach for most pegs, while the up-to-15-hour battery rating should cover a full day and plenty of overnight use. Keep a power bank in the bag if you’re planning a long campaign and relying heavily on your phone as well.
The biggest gain is confidence. You still need a decent rig, sensible baiting and the patience to let a swim develop. But when the rods are off and you’re wondering whether you’ve picked a proper spot or just convinced yourself, having a clearer picture can be a very handy edge.
On paper
Pros & cons
What we like
- Three beam options give you broad searching and more focused feature detail.
- Built-in GNSS makes mapping and repeatable spots far more useful.
- Compact 94 g body, hard case and night cover make it easy to carry.
- Up to 15 hours’ battery life should cover plenty of proper sessions.
- USB-C charging is dead handy compared with older proprietary cables.
Worth knowing
- You’ll need a compatible phone or tablet to view the sonar information.
- There’s a bit of learning and screen time involved before you can confidently read every return.
- It’s a serious investment compared with a simple marker float and lead setup.
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Your questions answered
What anglers want to know
The stuff you’d ask your mate on the next peg. Straight answers, no waffle.
01Can the Deeper CHIRP+ 4 work without mobile internet?
Can the Deeper CHIRP+ 4 work without mobile internet?
Yes. It connects to your phone or tablet over 2.4 GHz Wi-Fi, so an internet connection isn’t required while you’re scanning on the bank.
02How deep can the Deeper CHIRP+ 4 scan?
How deep can the Deeper CHIRP+ 4 scan?
Its stated maximum scanning depth is 100 metres, with a minimum scanning depth of 0.15 metres. On normal carp and coarse venues, that gives you plenty of range.
03What do the three sonar beams do?
What do the three sonar beams do?
The 100 kHz beam covers a wider area, the 240 kHz beam gives a more balanced view, and the narrow 675 kHz beam is useful when you want more focused detail over a specific feature.
What anglers say
The word from the bank
Our read: verdict. The strongest reasons to choose it are three beam options give you broad searching and more focused feature detail. and built-in gnss makes mapping and repeatable spots far more useful.; the main trade-off is you’ll need a compatible phone or tablet to view the sonar information..
Our take on the feedback
Why it appeals
Checked Sept '26 — “Three beam options give you broad searching and more focused feature detail.”
Best fit
Checked Sept '26 — “Carp anglers exploring unfamiliar lakes and pits: You can build a much clearer picture of depth changes, bars, holes and weed before settling on a spot.”
Worth knowing
Checked Sept '26 — “You’ll need a compatible phone or tablet to view the sonar information.”
Tackle Index’s take from the product details and fishing fit we checked. We haven’t found enough independent public feedback to call this an angler consensus yet.
Angler score
What our readers rate Deeper CHIRP+ 4 Smart Sonar
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Owner reports
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Quick multiple-choice reports from people who say they own the Deeper CHIRP+ 4 Smart Sonar. Not verified purchases, and kept separate from our score.
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