X515C DF & X510C Manual - Lowrance

Fish I.D. (Fish Symbols & Depths)
The Fish I.D. feature identifies targets that meet certain conditions as
fish. The microcomputer analyses all echoes and eliminates surface
clutter, thermoclines, and other signals that are undesirable. In most
instances, remaining targets are fish. The Fish I.D. feature displays
fish symbols on the screen in place of the actual fish echoes.
There are several fish symbol sizes. These are used to designate the
relative size between targets. In other words, Fish I.D. displays a small
fish symbol when it thinks a target is a small fish, a medium fish symbol
on a larger target and so on.
The sonar's microcomputer is sophisticated, but it can be fooled. It can't
distinguish between fish and other suspended objects such as trotlines,
turtles, submerged floats, air bubbles, etc. Individual tree limbs extending
outwards from a group of limbs is the hardest object for the
Fish I.D. feature to distinguish from fish.
You may see fish symbols on the screen when actually, there are no
fish. The reverse is also true. The illustrations on the next page show
how Fish I.D. can actually miss fish that are present.
Does that mean Fish I.D. is broken? No — the feature is simply interpreting
sonar returns in a specific way to help take some of the work
out of reading the screen. Remember: Fish I.D. is one of the many tools
we provide so you can analyze your sonar returns for maximum fish
finding information. This and other features can help you successfully
"see" beneath the boat under varied water and fishing conditions. So,
practice with the unit in both the Fish I.D. mode and without to become
more familiar with the feature. The default for Fish I.D. is off.
Sonar Features menu with Fish I.D. Symbols selected. When the check
box to the left is checked, the feature is on.
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