How to choose a fish finder
A smart fish finder is a floating sonar you cast into the water on your line, while your smartphone shows the picture in the Fish Deeper app. It shows depth, bottom contour and fish, and it works without internet because it connects to the phone directly over Wi-Fi. The range has two Deeper models: the beginner-friendly START and the CHIRP+ 4 with three CHIRP beams and satellite positioning.
Popular choices
Deeper Smart Sonar Chirp+4
Depth up to 100 m, three CHIRP beams, 1 cm target separation, GPS mapping and Wi-Fi up to 120 m.
Deeper Start Smart Fishfinder
An easy start: depth up to 50 m, a 40° beam, fish icons in the app and a flashing light for night fishing.
START vs CHIRP+ 4
| Spec | Deeper START | Deeper CHIRP+ 4 |
|---|---|---|
| Depth | 0.5-50 m | 0.15-100 m |
| Beams | 1 beam, 120 kHz, 40° | 3 CHIRP: 675, 240 and 100 kHz (7°, 20°, 47°) |
| Scan rate | 10 per second | up to 15 per second |
| Wi-Fi range | at least 50 m | up to 120 m |
| Battery life | up to 6 h | 9 h with GPS, 15 h without |
| Operating temperature | 0-40 °C | -20 to 40 °C |
What to look for
- Depth. For lakes and rivers 50 m is usually enough, while deeper waters and the sea call for the CHIRP+ 4 with up to 100 m.
- Beam angle. A narrow beam shows the bottom and fish right below the sonar precisely, a wide one covers a larger area. The CHIRP+ 4 switches between three beams, the START uses a single 40° beam.
- Mapping. With GPS, GLONASS, Galileo, BeiDou and QZSS the CHIRP+ 4 builds personal depth, bottom hardness and vegetation maps in 2D and 3D, and AI helps detect fish.
- Ice fishing. The CHIRP+ 4 works down to -20 °C, so it also suits ice fishing. The START is rated from 0 °C.
- Battery. The CHIRP+ 4 with a 1300 mAh battery runs up to 15 hours without GPS and up to 9 hours with GPS, the START with 850 mAh up to 6 hours. For a long day of fishing choose the CHIRP+ 4.
Frequently asked questions
Does a fish finder need internet?
No. The fish finder creates its own Wi-Fi network and connects to the phone directly, so you do not need mobile data at the water.
How far can I cast it?
The Deeper START keeps a connection up to at least 50 m (depending on the phone), the CHIRP+ 4 holds a stable connection up to 120 m.
How is it charged?
The CHIRP+ 4 charges via USB-C: 80% in 60 minutes, full in 110 minutes. The START charges with the included USB cable in 2.5 hours.
