Sonar Technology Fish ID

Fish ID is a display feature that replaces raw sonar returns with fish-shaped icons on your screen. The fish finder's processor analyzes incoming signals and, when it identifies a return that matches the characteristics of a fish, places a small, medium, or large fish icon at that depth on the display. Some units also display an estimated depth number next to each icon.

Fish ID mode is designed to simplify interpretation for beginners who have not yet learned to read traditional sonar arches. Instead of deciphering marks, colors, and shapes, you see an immediately recognizable fish symbol telling you something is there.

However, most experienced anglers avoid Fish ID mode because it introduces both false positives and false negatives. The algorithm frequently mistakes air bubbles, bait balls, debris, and turbulence for fish, cluttering the display with phantom icons. Conversely, it can fail to identify real fish that do not produce a textbook sonar return, like fish sitting very close to structure or tight to the bottom. This makes Fish ID less reliable than learning to interpret the raw sonar data yourself.

A better approach for new anglers is to run both views simultaneously on a split screen — raw sonar on one panel and Fish ID on the other. This lets you correlate the icons with the actual sonar marks, building your ability to read raw returns while still having the visual reference. Over time, most anglers find themselves relying entirely on the raw view and abandoning Fish ID as their interpretation skills improve.