Furuno FE-700 - Page 3

DBS Mode
HISTORY Mode
LOGBOOK Mode
This mode provides a mix of
Contour and Strata displays.
The Contour display can be
shifted back to the past over
24 h while the right side Strata
display (layers of different colors
according to reverberation
strengths) shows the latest five
minutes of sounding data.
This position of Mode
Selector displays the
logging on depths and
own ship positions with
associated time. You can
select the time intervals
among 5 s, 1 and 2 min
options on the Menu.
The log book contains 60
pages that can be
scrolled up or down with
[+] or [-] key. Entry to the
logbook is every 5 s over
24 h.
Depth Below Surface mode provides a
draft-adjusted depth reading and is
useful in referencing to the nautical
chart. The draft is adjustable with the
[DRAFT] key at the DBS position of
the Mode Selector. If you find any
difficulty to check for the draft value,
use the NAV mode, where you can
find the bottom clearance under the
keel.
50 kHz
200 kHz
OS DATA Mode
This display mode indicates
own ship position, GPS
derived course and speed,
time and depth in digital form.
The user may select the data
of particular interest to display
in large characters.
The screen continues to
display the sounding data in
the background. Part of
graphical indication is visible
to the right of data window.
The 50 kHz system is recommended for
deeper rang operation on large vessels
where aeration is not a problem or a long
cable is run from the cofferdam to the
navigation bridge. The photo at left is
from a sister version fish finder working
on 50 and 200 kHz dual frequencies just
to show the difference of sounding. Brown
parts are strong echoes from the seabed
or the highest concentration of fish
schools. They are more apparent on the
50 kHz. The 200 kHz system is more
immune to the surface noise caused by
aeration or when the ship is
going astern.
All underwater
objects including seabed
and fish schools and even
noise appear in layers of
different colors depending
on the sonic pulse
reflectivity. Brown is strongest,
followed by red, orange,
yellow, green, blue, dark blue -
total of eight colors.
200 kHz
Strata color display
The transducer is available in 200
kHz or 50 kHz. The 200 kHz system
is advantageous in rough weather or
congested waterways where there are
many bubbles or wakes of other
vessels. It is suitable in most echo
sounding applications in shallow
waters on the continental shelf.
50 kHz
(Echogram from a sister
version fish finder working
on 50 and 200 kHz)