Furuno FSV-35, Operator'S Manual

Page: 83 / 144

3. VERTICAL MODE
3-17
Smooth Echo CIR : Selects echo smoothing level in the circular direction. The setting
range is 0 to 5. The higher the setting, the greater the smoothing.
3.12 Application to Bonito and Tuna Fishing
Tracking of bonito and tuna presents a special challenge to the sonar operator: He
must try to keep them within the sonar beam, a formidable task considering their high
speed and penchant for leaping and diving. However, the vertical display, with its wide
range in the vertical direction, makes this task easier.
3.12.1 Searching
Neither the naked eye nor binoculars can continually track schools of fish which make
lightning quick runs between the surface and midwater. A sonar, however, provides a
continuous view of several hundred meters of sea area around the boat, both at the
surface and below it.
3.12.2 Tracking
If you are visually tracking a school of
fish which characteristically leaps and
dives regularly, or a school with a flock
of birds hovering over it, the school will
scatter once the vessel approaches,
thus you will lose sight of the school.
This sonar provides continuous pic-
tures of underwater conditions, so you
can always know where a school of fish
is. For tracking the schools which leap and dive often the vertical mode is especially
effective.