Furuno CH-250 manual Sample echo displays, Bottom echoes

2.14.2 Sample echo displays

Bottom echoes

When the tilt angle is changed, the bottom echo illustrated below will appear on the display. When the tilt is decrease (toward 0° ), the bottom trace becomes winder and weaker. By observing the bottom condition on the display, the skipper can prevent net damage.

(A) Flat bottom

Tilt angle: 10˚ to 15˚

(B) Flat bottom

Tilt angle: 20˚ or more

(C) Sloping bottom

Tilt angle: 20˚ or more

Decreased tilt angle Only half of vertical beam width captures the bottom.

Bottom is displayed narrower and in stronger colors when compared to (A).

Shallow bottom is displayed in a strong color and with a short tail.

Bottom

The deeper, sloping bottom echo is displayed in a weak color and with a long tail.

Figure 2-21 Bottom echoes

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