Humminbird 748 3D Operation Manual page 15

about the area under and adjacent to your boat, including the following items:
either device is connected to the Fishing System. If both devices are connected, then only
Boat/Direction Arrow - A simple, solid
3D boat is drawn when the Upper Depth
Range is 0. A solid 3D arrow is drawn
when the Upper Depth Range is not 0.
Upper and Lower Depth Range
Fish ID+™ - A fish icon will be shown at
the derived position of the fish. Six fish
icon styles will be used to indicate the
primary beam in which the fish was
found. Left-facing fish indicate fish off
the port side of the boat, while right-
facing fish indicate fish off the starboard
side. Each fish icon is available in three
different sizes. Larger fish icons are used
to represent stronger returns. The icons
used in the 2D Sonar View are identical
to the icons used in the 3D Sonar View.
Battery Voltage - The voltage of the
boat's battery; can be set to alarm if the
voltage falls below a certain point.
Frame - Provides a reference for bottom
and Fish ID information. A Range of
frame styles are available, from simple
to complex.
7 What's on the 3D Sonar Display