Castable or transom, and whether GPS comes with it
This shelf holds two different machines under one word. A castable sonar is a ball on the end of a line that talks to a phone: the Deeper Start at 98,99 €, the Deeper Smart Sonar Pro+ 2 at 199,99 €, the Garmin Striker Cast at 153,99 € and its GPS version at 192,90 €, the Deeper CHIRP+ 4 at 429 €. It is fished from a bank or a kayak and needs no boat at all. A mounted unit has its own screen and a transducer on the hull: the Garmin Striker Plus 4 at 166,99 €, the Striker Vivid with a 5-inch display at 384,58 €, the Lowrance Eagle at 205,25 €. The figures to read are the same for both. Depth range is printed on the cheaper units — 45 m on the DANOPLUS at 79,79 € — and a 45 m unit is useless for Norwegian cod and ample for a French lake. Frequency decides the trade: the word « Chirp » on the Garmin and Deeper models means the unit sweeps a band rather than pinging one note, which separates two fish that a single frequency shows as one. GPS is the feature that changes how the tool is used, because it turns a depth reading into a map you can return to, and it is the difference between the Striker Cast at 153,99 € and the Striker Cast GPS at 192,90 €. One listing is a third object entirely — the LOKEEVAN D50E at 289 € is a bait boat with sonar aboard. We compare format, depth range, frequency and Chirp, GPS, display size, battery life and mapping.
2,4-inch colour LCD · 21 operating languages · depth 147 ft (45 m) · 90° detection cone · fish alarm with size and depth · sonar sensor and fish-attracting lamp switch on automatically on touching water
The widest cone and the most languages, at the lowest price on the shelf.
Best for: A first sonar for kayak, ice or bank, where a wide sweep matters more than fine separation
Castable sonar · wide, medium and narrow beams · target separation 1 cm narrow, 2,4 cm wide and medium · own WiFi · integrated GPS for bathymetric maps from bank or jetty · free app
The only sonar here that publishes how far apart two targets must be to show as two.
Best for: Mapping an unfamiliar bank swim before fishing it, without a boat
Castable · depth to 45 m, shallow from 60 cm · wireless range 60 m · Quickdraw Contours maps with 30 cm depth lines · battery over 10 hours, USB · auto on in water, off out · requires line rated 9 kg or more
Depth, range, contour interval, battery and the line it needs — five figures, all published.
Best for: Reading a bank swim to 45 m and keeping the contours, with tackle already rated for the weight
CHIRP fish finder · simple navigation · speed shown on the display — the complete published specification
A well-known unit behind a listing that says almost nothing about it.
Best for: Someone who already knows the Striker Plus 4 and is buying a replacement
2,4-inch TFT colour LCD · depth 45 m · wireless range 150 m · wireless and simulation modes · fish-attracting lamp with a transparent spare cover · sensitivity, brightness, depth range, zoom, depth alarm, fish alarm, fish icon, units and language all adjustable · handset 4 h, sensor 10 h, USB
The only device here you can learn to use before going near water.
Best for: Night and ice fishing, where a lit sensor and a dedicated screen beat a phone
180 m depth reading · 300 m wireless range · 45° cone at 200 kHz · adaptive sensitivity for clear and murky water · depth range, shallow alarm, fish alarm and adjustable chart speed · suction cup or screw mounting
Publishes a frequency and a cone angle, and contradicts its own title twice.
Best for: Deep water from a boat, for a buyer willing to read the listing sceptically
4-inch IPS display, visible from all angles and through polarised glasses · twist-lock connector · vertical orientation · sonar
A mounted unit that solves the one problem a boat angler actually has: reading the screen.
Best for: A boat or kayak where the unit is fitted once and read in bright sun all day
The figure beside a product asked the shop for itself the moment this page opened; a figure inside the text has sat still since the sentence was written, and the first of the two is the one to trust.
