You are here: Home > Marine Product Guides > Fish Finder Guides > Garmin Fish Finder Comparison

What is CHIRP?

CHIRP is the most sophisticated sonar technology available for use by the fishing and boating public. The word itself is an acronym for Compressed High-Intensity Radiated Pulse.

Standard Sonar

Standard sonar sends 1 single frequency at a time. Since the only feedback is from this 1 single frequency, there is little information to work with, limiting the clarity and resolution available with standard sonar.


Instead of sending just 1 single frequency, CHIRP sends a continuous sweep of frequencies ranging from low to high. CHIRP sonar technology then interprets frequencies individually upon their return. Since this continuous sweep of frequencies provides CHIRP with a much wider range of information, CHIRP sonar is able to create a much clearer, higher resolution image.

CHIRP Scanning Sonar

CHIRP technology also enhances the performance and clarity of Garmin DownVü and SideVü scanning sonar to provide the clearest sonar images on the water.Types of Sonar

Traditional HD-ID Sonar

Traditional sonar that is available on Garmin fishfinders. HD-ID sonar transmits two frequencies, generally either 77/200 kHz or 50/200 kHz. Our echoMAP and GPSMAP chartplotter/sonar combos have Traditional HD-ID sonar built in.


CHIRP sonar transmits a sweep of many frequencies within a long duration pulse. The equivalent sound energy is hundreds of times greater, resulting in more energy on target. This provides huge advantages in detail, resolution and accuracy at much greater depths. CHIRP is built into our GPSMAP chartplotter/sonar combos


Panoptix all-seeing sonar is unlike anything you’ve ever seen on the water. Use the Panoptix Forward or Down transducer with a compatible Garmin GPSMAP unit to see all around your boat in real-time. You can see fish in the water column in 3-D. You can also see your bait cast into the water and watch it as you reel it in. You can see fish swimming in front of or below your boat. You can even see them chase your lure. But to truly appreciate Panoptix, you have to see it.

DownVü Scanning Sonar

This high-frequency sonar gives you a clearer picture of what's below your boat, by producing a more detailed representation of objects, structure and fish. DownVü with CHIRP technology takes it one step further, producing an ultra-clear page with even more detail. DownVü scanning sonar is built into our echoMAP combos, and DownVü scanning sonar with CHIRP technology is built into our GPSMAP combos. 

SideVü Scanning Sonar

SideVü shows you what is happening to the sides of your boat. An excellent way of finding structures and fish. SideVü with CHIRP technology provides an even more detailed and higher resolution image of what is beneath the surface. SideVü scanning sonar is built into our echoMAP sv combos, and SideVü scanning sonar with CHIRP technology is built into our GPSMAP combos. 


















Mounting Styles



is installed inside a boat hull against the bottom and sends its signal through the hull.



is attached to the back (transom) of a boat hull.



is installed in a hole drilled thru the hull.

Kayak In-Hull


attaches to the inside of a kayak, against the bottom and sends its signal though the hull.

Additional Information

Stepped Hull

A stepped hull contains a notch (or step) that runs crosswise across the boat hull and helps the boat generate more lift at higher speeds. If transducer is mounted after the notch, the notch creates cavitation and will interfere with sonar returns. For this reason, the transducer should be mounted in front of the notch, closer to the front of the boat.

Cored Hull

A cored hull refers to a hull with a void between the 2 layers of hull material. Sonar cannot transmit through that void.

Deadrise Angle

The deadrise angle is the angle between the horizontal line of the water and your boat's hull