Furuno CSH-53 manual Fish Schools, 2 Fish schools

Fish Schools

A fish school appears as a mass of echoes on the screen. The color of the mass shows the density of fish schools on the sonar beam. To find distribution and center point of a fish school, try several different tilt angles.

(A)Sea surface fish

Tilt angle: -5°to 10°

Fish school

Sea surface reflections

(B)Midwater, bottom fish Tilt angle: 30° or more

Fish echo which appears before seabed can be detected.

Seabed

Tilt angle: -0°to 20°

Fish echo which appears together with or after seabed can be detected.

Fish school

Seabed echo not displayed because of narrow tilt angle. Sea surface reflections are present.

Fish school

Large midwater fish school is present.

Seabed

Figure 11-2 Fish schools

11-2