Best Fish Finders

Built to map the bottom as well as find fish, the Deeper Smart Sonar CHIRP+ 4 is a castable sonar you clip to your line and read on a phone or tablet through its own Wi-Fi. Three CHIRP beams at 47°, 20° and 7° scan from 0.15m to 100m.

Its expert-trained AI marks fish on your own 2D and 3D maps, and the same scans produce maps of bottom hardness and weed. It comes with a hard case and a night cover, charges over USB-C, and links to your phone at up to 120m, depending on the handset.

Carp anglers who chart their swims in detail will get the most from it. Next to the Deeper Chirp+ 3, it adds AI fish ID and hardness and vegetation maps, which makes it the best castable fish finder in the line-up.

To be fair, it's the dearest of the castable picks, and the Chirp+ 3 covers 3D mapping for less. For anglers who need to pin down the gravel, silt and weed in a swim, though, I think it's money well spent.

Mapping is the Deeper Chirp+ 3's strong suit. Each cast adds to a personal 3D bathymetry map of depth, bottom structure and slopes in the Fish Deeper app, positioned by GPS, GLONASS, Galileo, BeiDou and QZSS.

Three beams at 7°, 20° and 47° let you focus tightly or scan widely, with 1cm target separation for small fish. Depth runs from 15cm to 100m, battery life is up to nine hours, and fast charging hits 80% in 45 minutes.

It suits carp anglers who want to chart a new water from the bank. Next to the Deeper Smart Sonar CHIRP+ 4, it trades the AI fish ID and hardness maps for a lower price, while the Deeper Chirp+ 2 lasts longer with GPS off but is slower to charge.

To be fair, its 100m Wi-Fi link is a little short of the CHIRP+ 4's reach. For anglers who mainly want accurate 3D maps of their swims, though, I think it's the smart buy in the Deeper range.

Three-frequency CHIRP is the core of the Deeper Chirp+ 2, a castable sonar you read in the Fish Deeper app. Its 7°, 20° and 47° beams cover 15cm to 100m, and the narrow one separates targets 1cm apart.

Battery life is its strong point, at up to 15 hours with GPS off, and its own Wi-Fi holds a stable link to 120m without mobile data. The box includes a neoprene pouch and a night cover, and it tracks small lures when vertical jigging.

Bank anglers who fish long days will like it, and so will boat or kayak anglers jigging for perch and zander. Next to the Deeper Chirp+ 3, it runs longer but charges more slowly, while the Deeper Pro+ 2 costs less and adds mounts for a boat and a rod.

To be fair, a full charge takes 110 minutes, so it's one to charge the night before. For a dependable CHIRP sonar that lasts all day, though, I think it's very good value.

Light and portable, the Deeper Pro+ 2 is a three-beam sonar built for the bank, a boat or a kayak. Its beams at 47°, 20° and 7° read down to 100m, with 1cm target separation on the narrow beam.

Titanium inserts and a silicone gasket toughen up its ABS shell, and built-in GPS saves bathymetric maps to the Fish Deeper app. Mounts for a boat or kayak and for your rod come with it.

For mixed bank and boat fishing, it makes a lot of sense. Next to the Deeper Chirp+ 2, it costs less and adds the mounts, while the Chirp+ 2 adds CHIRP and longer battery life. The Rippton HydroBat costs a little more and has two beams to the Pro+ 2's three.

To be fair, up to nine hours of battery life is shorter than the Chirp+ 2 manages with GPS off. For an all-round sonar that moves easily from bank to boat, though, I think it's a smart buy.

The Rippton HydroBat Castable Sonar is a small, simple fish finder for shore anglers and family trips. It reads from 0.6m to 120m through a wide 55° beam and a narrower 15° beam, and shows fish, depth, contour and weed on the free Rippton app.

It makes its own Wi-Fi and connects at 80 to 100m on its own, with no wires or external batteries. The 1,500mAh battery runs for 5.5 to 6 hours, every scan saves with its time and location, and the 68mm body has an IP68 water rating.

It suits bank anglers who want to find depth, drop-offs and weed without a lot of settings. Next to the Deeper Pro+ 2, it reads deeper, but the Deeper adds a third beam and built-in GPS mapping, while the Deeper Start is cheaper and simpler again, with one beam to 50m.

To be fair, it's a little dearer than the Deeper Pro+ 2, and keen mappers will want more. For families and casual shore anglers, though, I think it's a very easy castable to live with.

The Deeper Start Fishfinder is the simplest castable sonar in this guide, and the easiest way in for a beginner. It has a single 120 kHz beam with a 40° cone, reads from 0.5m to 50m and shows fish icons with their size and depth in the Fish Deeper app.

It switches on in the water, links over Wi-Fi at up to 50m and runs for up to six hours. Basic mode keeps the view clean for beginners, Raw mode shows the unfiltered data, and it charges from a magnetic USB cable.

It suits beginners, younger anglers and anyone who wants depth and features without a big spend. Next to the Rippton HydroBat, it reads less deep with one beam rather than two, but it's lighter and much cheaper, while the Deeper Pro+ 2 adds three beams and GPS mapping.

To be fair, a single beam to 50m won't map a big water in fine detail. For a first fish finder on the bank, though, I think it's the best value pick in this guide.

The Humminbird XPLORE CMSI+ is a fish finder and GPS chart plotter with a Full-HD 1280 x 800 touchscreen. It runs MEGA Side Imaging+ and MEGA Down Imaging+, each reaching up to 200ft, plus Dual Spectrum CHIRP sonar that reads to 360m.

LakeMaster and CoastMaster charts are included, it works with Navionics charts, and up to 10,000 fish spots sync to your phone. Cross Touch means you can use the screen or the keypad, and it comes in 9, 10 and 12-inch sizes.

It's built for boat anglers after pike, predators or sea fish on big water. Next to the Deeper Start Fishfinder, a simple castable for the bank, it's a different class of tool. Compared with the Humminbird Mega Live 2, it's one of the displays that live sonar add-on needs, so the two pair up well.

To be fair, it's a big outlay and there's a lot to learn. For a serious boat angler who wants to find, mark and return to features, though, I think it's the best boat fish finder in this guide.

The Humminbird Mega Live 2 is a live sonar add-on, not a stand-alone fish finder. It needs a compatible Humminbird APEX, SOLIX G3 or XPLORE display, and the transducer mounts on either side of a trolling-motor shaft.

Forward, Down and Landscape views show fish and structure live, out to 45m. It covers 20 x 120 degrees on a 1005kHz CHIRP frequency, bottom interference is removed to keep the picture clean, and it works with Minn Kota trolling motors.

It suits pike and predator anglers who fish from a boat with a trolling motor. Next to the Humminbird XPLORE CMSI+, it's the add-on rather than the screen, and the two pair together. Compared with the Humminbird Piranha MAX 4 DI, a simple all-in-one unit, it's a far bigger step and a far bigger outlay.

To be fair, you need the right display and motor before it shows you anything. For boat anglers who already run a compatible Humminbird screen, though, I think it's a superb upgrade.

The Humminbird Piranha MAX 4 DI puts Down Imaging and Dual Beam sonar on a 4.3-inch, 256-colour screen. Down Imaging reads to 320ft, and the sonar reaches 600ft at 200 kHz, so it shows timber, rocks and bottom detail clearly.

Fish ID+, fish alarms, depth alarms and zoom run from a simple keypad. The XNT 9 DI T transducer mounts on the transom, and the gimbal mount tilts and swivels so you can angle the screen.

It suits small-boat anglers after pike, perch, zander or sea fish who want a clear view of the bottom. Next to the Humminbird Mega Live 2, it's a complete unit in one box and a far smaller outlay. Compared with the Humminbird Piranha MAX 4, it adds the picture-like Down Imaging view for a little more.

To be fair, the screen is small and GPS chartplotting isn't supported. For a first boat fish finder that shows structure clearly, though, I think it's very good value.

The Humminbird Piranha MAX 4 is a simple Dual Beam fish finder with a 4.3-inch colour screen. It works at 200/455kHz with 2.5-inch target separation, and it reads down to 600ft with 300 watts RMS of output.

Fish-ID+ helps pick out fish, and the transducer has temperature built in. The XNT-9-28-T transducer mounts on the transom with a 6m cable, and the unit measures 99 x 186 x 92mm on its gimbal.

For me, it suits kayak anglers and small-boat anglers who want depth and fish without a lot to learn. Next to the Humminbird Piranha MAX 4 DI, it gives up Down Imaging for a smaller outlay. Compared with the Toslon TF740, a bait boat unit for carp anglers, it's a different tool for a different job.

To be fair, the screen is small and it's traditional sonar rather than imaging. For a compact, no-fuss kayak fish finder, though, I think it's very hard to fault.

The Toslon TF740 is the best bait boat fish finder in this guide, because it does far more than show depth. It brings wireless sonar to 40m, GPS accurate to around 2.5m, a compass and autopilot together on a 5in colour screen.

Save a spot, press PUSH-GO and the boat heads back to it. It stores 500 waypoints and 10 routes, imports Google Earth .kml lake outlines, works with twin-motor and rudder-based boats, and comes with an internal 12V 5.2Ah Li-ion battery and charger.

It suits carp anglers with a bait boat who fish big waters and want the same spot every time. Next to the Humminbird Piranha MAX 4, which mounts on your own boat or kayak, it's made for a bait boat, while the Toslon TF520 is a simpler, cheaper sonar-only unit.

To be fair, it's one of the dearer units, and you need a compatible bait boat. For carp anglers who already run one, though, I think it's the one to have.

The Toslon TF520 is a wireless sonar for carp anglers with a bait boat. It shows fish, obstacles, hills and holes on a 4.3in sunlight-viewable colour screen, through 115kHz sonar with a 60° beam that reads to 30m.

It tells hard and soft bottoms apart, has a 300m wireless range on 2.4GHz radio, and shows the bait boat's battery voltage. The casing is IPX6 waterproof, and a portable case comes with it.

It suits carp anglers who want to read the lakebed and set zig depths from a bait boat. Next to the Toslon TF740, it's much cheaper and simpler to learn, and its bottom-hardness reading suits anglers who mainly want clean, firm spots for their rigs.

To be fair, it's a sonar-only unit, so the boat won't find its own way back to a spot. For a clear picture of what's under the boat, though, I think it's a very sound buy.