Humminbird 561 - Manual (Page 21)

What’s on the Down Imaging™ Display 14
(Down Imaging™ models only [570 DI])
information about the area directly below your boat. The razor-thin, high-definition
Down Imaging™ reveals a variety of recognizable features so that you can
to the 500 Series™ Fishfinder.
Clouded Area may indicate a bait ball and
White Streaks may indicate fish.
Upper Range
Structure
Lower Range
Bottom Return - Use the appearance of the
bottom return to determine bottom hardness.
Rock and gravel provide a clearer sonar
return than mud and sand because hard
objects reflect sonar better than soft objects.
Shadows- Result from a lack of reflected
sonar from a particular area and can be as
valuable for interpretation than the sonar
reflected by the object itself. Use shadows to
help you see the image in 3 dimensions,
oriented in space. You can gain insight into
the actual shape of an object, or the depth
to which it has sunk into the bottom,
through shadows on the display. Objects
standing on the bottom cast a sonar
shadow. The longer the shadow, the taller
the object. Fish also cast shadows. You can
use the shadow to interpret how close the
fish is to the bottom.