How Do I Interpret The Bottom Structure - Raymarine C-Series Reference Manual

Chapter 7: Using the Fishfinder

How do I interpret the bottom structure?

The bottom usually produces a strong echo . These images indicate the bottom
conditions as follows:.
A hard bottom (sand) produces a thin line
A soft bottom (mud or seaweed cover) produces a wide line. The dark
layer indicates a strong signal.
-
A rocky or uneven bottom or a wreck produces an irregular image with
peaks and troughs
The dark layers indicate a good echo; the lighter areas weaker echoes. This could mean
that the upper layer is soft and therefore allowing sound waves to pass to the more
solid layer below.
It is also possible that the sound waves are making two complete trips – hitting the
bottom, bouncing off the boat, then reflecting off the bottom again. This can happen if
the water is shallow, the bottom is hard, or gain is set high.
The C-Series Fishfinder provides various features to help you interpret the fishfinder
picture; these are described in
page 7
.
7-3
D6855-1