Down imaging
Also called DownScan, ClearVü, downscan imaging
High-frequency sonar that draws near-photographic, top-down detail of whatever is directly below the boat.
Where traditional 2D sonar gives you a fuzzy impression, down imaging gives you a picture. Brush looks like brush, a standing tree looks like a tree, and rock looks different from mud. Garmin calls it ClearVü and Lowrance calls it DownScan, which are the same idea under different names.
The tradeoff is that the very high frequencies that produce that detail penetrate less deeply and are less good at showing fish as distinct targets. Down imaging is for reading structure; 2D CHIRP is for finding fish in it.
Most units run both side by side on a split screen, which is how they are meant to be used. Reading them together is the skill: 2D tells you something is there, down imaging tells you what it is sitting in.
Side imaging is the related feature that looks out sideways rather than down, sweeping a corridor to the left and right of the boat. It is the better search tool of the two and it costs more.
Use down imaging to identify what the cover is, then switch to 2D or split screen to see whether anything is living in it.
Related terms
Where this comes up
The guides that use down imaging and show it on real gear.
Down imaging is one of 206 terms in the glossary.
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