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Furuno GP-3500F User Manual

Page 216

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11. VIDEO SOUNDER OPERATION

11-44

Current rip
A current rip develops when two ocean currents of different speeds, directions
and water temperatures meet. Its on-screen appearance is as shown below.

Current Rip

Current rip

Surface noise
When the sea is rough or the ship passes over a wake, surface noise may
appear at the top of the screen. It can be suppressed with the CLUTTER
FUNCTION.

Surface Noise

Surface noise

Aerated water
When the sea is rough or the ship makes a quick turn, gaps in the bottom echo
on the screen may appear. This is caused by air bubbles which block
propagation of the sound wave. Generally low frequency ultrasonic waves are
interrupted more easily than high ones.

Ultrasonic wave
blocked by
aerated water

Aerated water