CHIRP and traditional sonar both use sound to find fish and structure beneath your hull, but they don’t do it the same way — and the difference explains why CHIRP units tend to cost more and show a noticeably sharper picture.
How traditional sonar works
A traditional single-frequency transducer sends out one pulse at a fixed frequency (commonly 50kHz or 200kHz), waits for the echo, then fires again. It’s simple, cheap to produce, and works fine in open water — but closely spaced targets like fish holding tight to structure can blur into a single blob on screen.
How CHIRP changes the picture
CHIRP (Compressed High-Intensity Radiated Pulse) sweeps continuously through a range of frequencies in every pulse, rather than firing one fixed tone. Processing that sweep gives far more return data per pulse, which the fish finder uses to separate individual fish, distinguish bait balls from structure, and hold detail at greater depth.
| Feature | Traditional Sonar | CHIRP Sonar |
|---|---|---|
| Frequency | Single, fixed | Swept range per pulse |
| Target separation | Can blur close targets | Sharp separation, even close together |
| Deep water performance | Loses detail with depth | Holds detail much deeper |
| Typical price | Lower | Higher |
Does it actually matter for UK anglers?
If you fish mixed depths, mark bait balls, or want to pick individual fish out of a shoal rather than seeing a smudge, CHIRP earns its price premium. For simple depth reading in shallow, clear water, a traditional single-frequency unit still does the job at a lower cost.
Not sure which sonar type suits your boat and the waters you fish? Get in touch and we’ll help you match a fish finder to your budget.