Deeper PRO+ 2 Review: Castable GPS Sonar for Shore, Kayak, and Ice
Our Deeper PRO+ 2 review covers its three beams, 330 ft depth range, GPS mapping, casting setup, ice fishing mode, cold charging limit, and owner reports.
Updated October 31, 2026
The Deeper PRO+ 2 is a castable sonar: a small float you tie to a line, clamp to a kayak, or drop through an ice hole, which sends readings to the Fish Deeper app on your phone over its own Wi-Fi network. Deeper lists three sonar beams, a depth range of 15 cm to 100 m (about 6 in to 330 ft), and built-in satellite positioning for making your own depth maps.
Our verdict: it suits bank, pier, kayak, and ice anglers who want more depth range and a narrower beam than an entry-level castable, plus GPS mapping, without mounting a unit. Plan on a dedicated rod with heavy line and indoor charging in winter. This review is based on research, not our own trials.
This guide is general product information, not repair or electrical safety advice. Follow the installation, wiring, and charging instructions in your product’s manual, stop using any battery, charger, or electronics that overheat, swell, or smell of burning, and contact the manufacturer.
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Deeper PRO+ 2 Castable Sonar
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Deeper PRO+ 2 at a Glance
Figures come from Deeper’s PRO+ 2 page and its Quick Guide for the CHIRP+ 2 and PRO+ 2; Deeper lists no weight, so that row uses the Amazon listing.
| Spec | Deeper PRO+ 2 |
|---|---|
| Sonar beams | Wide 100 kHz (47 degree cone), medium 240 kHz (20 degree cone), narrow 675 kHz (7 degree cone) |
| Depth range | 15 cm to 100 m (about 6 in to 330 ft) |
| Target separation | 1 cm narrow beam, 2.4 cm medium and wide beams (about 0.4 in and 0.9 in) |
| Scan rate | Up to 15 per second |
| Connection | Its own Wi-Fi network, stable connection up to 100 m |
| Positioning | GPS, GLONASS, Galileo, BeiDou, QZSS |
| Battery | 3.7 V lithium-ion, 950 mAh; up to 9 hours depending on use; 80% in 45 minutes, 100% in 75 minutes |
| Temperature | Operates from -4°F to 104°F; will not charge below 37.4°F (3°C), per the Quick Guide |
| In the box | Sonar, USB cable, neoprene pouch, two attachment bolts (one is a spare), Quick Guide; no wall adapter |
| Weight | 3.2 oz (per the Amazon listing) |
| Warranty | 2-year limited |
What We Like
- Three beams, from a 47 degree search cone down to a 7 degree cone for detail under the float.
- A 100 m (about 330 ft) depth range, twice what Deeper lists for the Start.
- Built-in satellite positioning for mapping from shore, a kayak, or the ice.
- Separate Boat and Ice Fishing modes in the app, per Deeper’s Quick Guide.
What Could Be Better
- Your phone is the only screen, and Deeper warns the link may be unstable with the phone on the ground or in a pocket.
- Casting it takes a dedicated rod and heavy line, according to owner reviews.
- One owner reports a unit that stopped charging twice, the second time after the warranty ran out.
- The Amazon listing gives a 2.4 inch display size, but Deeper describes a sonar that streams to your phone, so ignore that field.
Deeper PRO+ 2 Sonar: Three Beams and What They Cover
A sonar beam is a cone that widens as it goes down, so the beam you pick decides how much bottom you see. One owner shares a rule that matches basic trigonometry: multiply the water depth by about 0.87 for the 47 degree beam, 0.35 for the 20 degree beam, and 0.12 for the 7 degree beam to get the cone’s width at that depth. In 20 ft of water, that is roughly 17 ft, 7 ft, and 2.4 ft across.
Use the wide beam to search a flat or a drop-off, and the narrow beam when you sit over a spot and watch a jig near bottom.
One owner notes that, as with any castable, it reads only the water under the float, and the scrolling 2D view cannot show which side of the float a fish is on. The same owner saw false fish marks from kayak paddle churn and sudden current, and calls it impractical in rocky creeks where an impact could damage it.
Shore, Kayak, and Ice: Setting Up Each Mode
From shore or a pier. Deeper’s shore fishing guide says to use the bottom attachment point from shore and the middle one from a dock or pier, with only one bolt; the second is a spare. The wrong point tilts the sonar, which Deeper says hurts the connection and sonar accuracy. Its casting guide says you can cast up to 100 m (about 330 ft) and watch scans as you reel back slowly.
Owners agree it needs its own rod. One uses 50 lb braid; another had a reel bail close mid-cast, snapping 50 lb braid and sending the sonar into the middle of the lake, then moved up to 80 lb braid with a mono leader. Deeper’s checklist asks for unworn line, tied firmly to the bolt.
From a kayak or boat. Deeper’s trolling guide points to Boat mode for a split view of scanning and mapping and recommends staying at or under 5 km/h (2.7 knots); the product page suggests about 3 kph for accurate readings. Deeper’s boat and kayak guide shows mounting on its Flexible Arm or Flexible Arm 2.0 accessory, which is not in the box.
On the ice. Deeper’s ice fishing guide says to turn on Ice Fishing Mode, drop the sonar in the hole, and keep it centered so the readings do not catch the ice; a line is optional. Each hole is marked on your map automatically. One ice angler likes moving hole to hole without a heavy lead battery and switching beam angles as needed.
GPS Mapping, the App, and the Wi-Fi Link
Deeper lists GPS, GLONASS, Galileo, BeiDou, and QZSS positioning. According to the Amazon listing, the GPS lets you create bathymetric maps from the shore, dock, or bank. Deeper says maps save to the Fish Deeper app and sync across devices, and you can mark spots and log catches. Deeper also lists Premium Maps with 2D depth and 3D terrain maps but does not say how they are priced; one owner says the community scans came with a Pro account they paid for.
Owners differ on mapping. One saves favorite spots, and another spotted a deep hole just past a branch. One reports that large scans can take several attempts to upload, and another sees an upgrade offer each time the app starts.
Because the sonar makes its own Wi-Fi network, it works without cell service. Owner reports run from a connection “a couple hundred feet” away to occasional dropouts with the phone 3 feet away. Deeper’s guides say it pairs with one phone at a time.
Battery, Charging, and Durability
Deeper lists a 950 mAh lithium-ion battery with up to 9 hours of use, depending on usage, and recommends a 5 V, 2 A USB adapter (not included). Owner reports include 5 to 7 hours of constant use, about 6 hours, and “all day” on the ice.
Deeper’s charging guide says the battery cannot charge below 37.4°F (3°C) and shows a blue light when it is too cold, so warm it to room temperature first. It also says to dry the sonar before opening the top cover, keep the threads free of sand, close the cover with the Water Proof marks aligned, and never put it in water with the charging cable attached.
Durability reports are mixed. One owner’s first unit stopped charging and stopped sending Wi-Fi within months, and Deeper replaced it under warranty; the replacement failed the same way about two and a half years later, after what the owner describes as a one-year warranty had ended. Another reports two years of use from the bank to the ice. Deeper and the listing both give a 2-year limited warranty.
What Owners Say
We read the eight owner reviews available on this Amazon listing. Beyond the comments above:
- Where they use it: piers, banks, kayaks, and the ice, often more than one.
- Setup: owners generally call it easy to use: one after the initial setup, one noting it pairs right up with the app. Another adds that you need to work out which mode suits each situation, and a fourth is still learning it.
- What it is good for: one river angler says its real value is showing depth, bottom structure, and the depth band where fish are moving.
- Small complaints: one owner sometimes loses sight of the black float on the water.
How the Deeper PRO+ 2 Compares
Against the Deeper Start, the PRO+ 2 lists two more beams, twice the depth range, built-in positioning (Deeper’s Start page lists none), a longer stated runtime, and operation below freezing. Against the Garmin Striker Cast, it lists more than twice the depth range (100 m against 150 ft), the narrower 7 degree beam, and positioning without buying a separate GPS version, while the Striker Cast is lighter per the listings and lists 10 hours of typical use on its product page. Both need warmth to charge: Deeper says the PRO+ 2 will not charge below 37.4°F, and Garmin’s Striker Cast manual lists charging from 41°F. Our Deeper vs Striker Cast comparison covers that choice in detail, and our Garmin Striker Cast review covers both Garmin versions.
Who Should Look Elsewhere
- Boat anglers who want a screen that works without a phone, or down and side imaging. Mounted units are covered in our roundup of the best fish finders and the Fish Finders section.
- Anglers who want to scan while running faster than about 5 km/h, the top speed in Deeper’s trolling guide.
- Ice anglers who prefer a dedicated flasher with its own dial. Our ice fishing fish finder roundup covers flashers and portable kits.
- Shore anglers who do not want to carry a second rod spooled with heavy line.
- Newcomers to sonar screens: start with our guide on how to read a fish finder.
Why You Should Trust Us
We do not run our own product trials. This review draws on Deeper’s PRO+ 2 and Start pages, Deeper’s Quick Guide for the PRO+ 2, the Amazon listing and the eight owner reviews available on it, and Garmin’s Striker Cast page and manual. Each AnglerTechLab Score starts from Amazon owner ratings, with a limited editorial adjustment explained on our How We Review page; we lowered this listing’s score by 0.2 because it gives a 2.4 inch display size and an OLED or small LCD display type for a sonar that has no screen of its own.
Final Verdict
The Deeper PRO+ 2 gives your phone three sonar beams, a 100 m depth range, and its own GPS mapping, in a float that works from shore, a kayak, or an ice hole. Budget for a dedicated rod with heavy line and indoor charging in cold weather; for shallow, warm water without mapping, the Deeper Start may be enough.
Frequently Asked Questions
How deep does the Deeper Sonar PRO+ 2 read?
Deeper lists 15 cm to 100 m, about 6 in to 330 ft.
Is the Deeper PRO+ 2 good for ice fishing?
Deeper sells it as an ice fishing flasher, with an Ice Fishing Mode and an operating range down to -4°F. Charge it at home, since the battery will not charge below 37.4°F.
Does the Deeper Smart Sonar PRO+ 2 need cell service?
No. Deeper says it creates its own Wi-Fi network, so no cellular data is needed. You need the Fish Deeper app, and registering unlocks every feature.
What line do you need to cast the Deeper PRO+ 2 sonar?
The Deeper support guides we read give no line rating. Owners on the listing use 50 lb to 80 lb braid on a dedicated rod.
Can you use the Deeper PRO+ 2 sonar fish finder from a kayak?
Yes. Deeper’s guide covers kayaks with a Deeper Flexible Arm accessory (not in the box) and Boat mode in the app.
About the author
Mason McKinney enjoys fishing Minnesota's lakes for crappie, walleye, and other freshwater species. He uses forward-facing sonar, GPS fish finders, and spot-lock trolling motors to locate fish around underwater structures and maintain precise boat positioning.