Operation Manual
FarSounder, Inc.
F31552 (Rev. 3.8.0)
Page 48 of 69
6.2. Chart Overlay Explained
Realtime Sonar Data
All 3D sonar data is displayed as an overlay on top of the nautical chart. This overlay capability increases
user comprehension significantly as "stray" in-water targets often correspond to a feature included on the
chart. Sometimes such features are not well located on the chart (such as markings indicating simply "rocks"
or "reef"). The sonar is able to locate the actual positions of these features as indicated by the overlay.
In the overlay, the seafloor and in-water targets are drawn as a translucent surface on top of the chart. Color
is mapped to the same color scale settings used in the 3D Sonar display.
Local History Mapping Data™ (LHM)
Seafloor data is persisted for the last hour of operation and displayed as an overlay on top of the nautical
chart. The LHM display color is mapped to the same color settings used by the 3D viewer.
6.3. Menu Bar Controls
Auto Center
When depressed, the vessel graphic will remain in the window with any new GPS information updates
received by the Digital Chart Viewer. Otherwise, the vessel will move across the chart with each latitude/
longitude position update.
Zoom In
Clicking this button will zoom in on the scale of the chart. If auto center is depressed, then the boat will be
at the center of the newly zoomed view. If auto center is not checked, then the zooming will be centered
on the center of the displayed chart.
Zoom Out
Clicking this button will zoom out on the scale of the chart. If auto center is depressed, then the boat will
be at the center of the newly zoomed view. If auto center is not checked, then the zooming will be centered
on the center of the displayed chart.
ERBL
Electronic Range and Bearing Line. When depressed, a line is drawn from the bow of the vessel to the
cursor. The status window displays the distance between the bow and the cursor, as well as the relative
bearing and absolute bearing.
6.4. Mouse Controls
Left Button Mouse Click
Clicking the left mouse button will pan the chart image by centering the chart on the mouse position.
Right Button Mouse Drag
Dragging the mouse with the right mouse button down will draw an orange range line from the initial mouse
position when first depressed to the final mouse position when released. While the button is depressed, the
