Humminbird 500 Series Operation Manual page 17

the area under your boat, including the following items:
device is connected to the 500 Series™ Fishfinder. If both devices are connected, then only
Bait Ball
Hollow Fish Symbol (83kHz, Wide Beam)
Fish - The Fishfinder displays fish as arches
and/or fish icons, and can be set to alarm
when a fish of a certain size is detected.
When a target is detected, a Fish ID+™
symbol appears on the display with the
depth displayed above it. The size of the
symbol indicates the intensity of the sonar
return. The unit will clearly show schools of
Bait Fish as "clouds" of different shapes and
sizes, depending on the number of fish and
boat speed.
Thermoclines - Layers of water with different
temperatures that appear at different depths
and different times of the year. A thermocline
typically appears as a continuous band of gray
levels moving across the display at the same
depth.
Cursor - Available in Freeze Frame and can
be positioned in the Sonar View to provide
depth of a sonar return and bottom depth below
the cursor.
Shaded Fish Symbol (200 kHz, Narrow Beam)
RTS (Real Time Sonar) Window™
Structure - Where fish may be hiding.
7 What's On the Sonar Display