Raymarine L470 - Manual (Page 60)

54
Operating Instructions
Bottom Lock Mode
The normal display on the FishFinder is a “top-down” view, as if it was
seen from the surface of the water. The Bottom Lock Mode shows a
“bottom-up” view. The bottom is used as a reference,
and all depths are
measured up from the bottom.
You can reach the Bottom Lock Mode at any time by pressing the
BOT
LOCK
button. For a moment, the display will say, “ENTERING BOTTOM LOCK,”
then the Bottom Lock image will appear.
Figure 3-15 shows the FishFinder Page with the split Bottom Lock feature
enabled. The right section of the split image shows a section of the
normal FishFinder Page. The left section shows the Bottom Lock image.
Bottom indication
The actual surface of the bottom under your boat varies in
depth and contour. The bottom lock feature “flattens out”
the bottom image to give you greater visibility of fish targets
or structure resting on or near the bottom. On the Bottom
Lock image,
the bottom itself is shown as a flat surface, and
all targets are shown relative to this flattened bottom.
When using Bottom Lock, you will probably want to keep
the Range (
not the Bottom Lock Range) set to Auto. If the
Range is set to Manual, and the bottom moves deeper than
Fig. 3-15
Bottom Lock
Mode
Top and
bottom of
Bottom
Lock range
Bottom
indication
Bottom
depth below
surface
Bar
indicates
area being
displayed