Other Echoes - Furuno FCV-1200L Operator's Manual

Fish school density
If two fish scools appear with the same color at different depths, the one in deeper water is
denser because the ultrasonic wave attenuates as it propagates and the fish school in deep
water tends to be displayed in a weaker color.
Fish Echo
4.5

Other Echoes

Plankton
A plamkton layer, a likely place to find fish, is displayed in green or blue dots. It usually descends
in the day and rises at night.
Current rip
When two ocean currents meet with different speeds, directions and water temperatures, a
current rip develops. A current rip's on-screen appearance is as shown below.
4-4
Less Reddish
(Sparse echo)
Difference in
Reddish
signal strength
(Dense echo)
Fish school density
Plankton
Fish School
Plankton
Current Rip
Current rip
Strong
Echo
Weak Echo