Furuno FSV-85, Operator'S Manual

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3. VERTICAL MODE
3-17
V-Scan Color 1 (2 to 4) Setting : Customizes colors. For details, see page 2-38.
V-Scan Color Curve Setting : Adjusts reflected echo strength versus echo color level
for currently selected color response number. To adjust the curve, see page 2-38.
Picture Setting menu
Smooth Echo RNG : Selects echo smoothing level in the range direction. The setting
range is 0-7. The higher the setting, the greater the smoothing.
Smooth Echo CIR : Selects echo smoothing level in the circular direction. The setting
range is 0-5. 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 pictures 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 espe-
cially effective.