Understanding Sonar History; Real Time Sonar (Rts®) Window; Freeze Frame; Bottom Presentation - Humminbird 787C2 Operation Manual

531476-1_A - 787c2_Eng.qxd 11/22/2005

Understanding Sonar History

It is important to understand the significance of the 700
Series™ Fishing System display. The display does NOT
show a literal 3-dimensional representation of what is
under the water. Each vertical band of data received by
the control head and plotted on the display represents
something that was detected by a sonar return at a
particular time. As both the boat and the targets (fish)
may be moving, the returns are only showing a
particular segment of time when objects were detected,
not exactly where those objects are in relation to other
objects shown on the display.
Real Time Sonar (RTS®) Window
A Real Time Sonar (RTS®) Window appears on the right side of the display in the Sonar
View only. The RTS® Window always updates at the fastest rate possible for depth
conditions and shows only the returns from the bottom, structure and fish that are
within the transducer beam. The RTS® Window plots the depth and intensity of a sonar
return. (See Sonar Menu: RTS® Window) .
The Narrow RTS® Window
indicates the sonar intensity
through the use of colors.
Red indicates a strong return
and blue indicates a weak
return. The depth of the
sonar return is indicated by
the vertical placement of the
return on the display depth
scale.
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The Wide RTS® Window
in
dicates the sonar intensity
through the use of a bar
graph. The length of the
plotted return provides an
indication of whether the
return is weak or strong. The
depth of the sonar return is
indicated by the vertical
placement of the return on
the display depth scale.
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Freeze Frame

Freeze Frame - Pressing any arrow on the 4-WAY Cursor Control key will freeze the screen
and a cursor will be displayed on the screen. The cursor can be positioned on the display
usingthe 4-WAY Cursor Control key to determine the depth of any sonar return. The
RTS® Window continues to update in Freeze Frame. In addition, see the effects of menu
setting changes with Instant Image Update. Pressing EXIT will exit Freeze Frame and the
display will start to scroll. Freeze Frame is available in the Sonar, Sonar Zoom, and
200/83 kHz Split Sonar Views.

Bottom Presentation

As the boat moves, the unit charts the changes in depth on the display to create a profile
of the Bottom Contour. The type of bottom can be determined from the return charted
on the display. A Hard Bottom such as compacted sediment or flat rock appears as a
thinner line across the display. A Soft Bottom such as mud or sand appears as a thicker
line across the display. Rocky Bottoms have a broken, random appearance.
Bottom Contour Profile with RTS® Window.
Temp/Speed Accessory is optional.
Hard Bottom
Rocky Bottom
The sonar returns from the bottom, structure and fish can be represented as either
WhiteLine® or Structure ID®. See Sonar Menu Tab: Bottom View for details on how to
set the bottom view.
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Soft Bottom