Vexilar LC-507 - Manual (Page 21)

21
SEEING STRUCTURE
Here, structure is defined as anything from a drop-off to a rock
pile or weed bed. The comparison of the two beams gives you the
ability to see structure like never before. The narrow 400 kHz cone
allows you to see sharp breaks and individual items, such as rocks
or stumps. The wider 107 kHz cone will show you these same things
further away from your boat, but with less detail. Notice, in figure
24, as the
boat moves
over the
drop-off the
400 kHz
beam shows
the slope
p r e c i s e l y.
The 107
kHz beam,
on the other
hand, shows a much different signal. The slope appears to more
gradual and the bottom is much thicker. This is due to the wider
cone covering more area. Notice the extra line coming down next
to the bottom. This is another part of the slope that is off to the side.
Figure 25
shows a boat
passing over
a deeper
hole. Notice
how the nar-
row cone
draws the
hole very
well, but the
wide 107 kHz cone seems to smooth it out. If there are fish in the
hole you are more likely to be able to see them with the narrower
cone. However, if the fish are hanging on the edge of the hole, the
107 kHz beam may see them better.
Figure 24
Figure 25