Raymarine Marine GPS System manual Fish Indications, To display the depth of the fish

RayTech Navigator User’s Guide

Fish Indications

When the Fishfinder detects a fish, it displays an arch-shaped mark. In general, a larger arch indicates a larger fish, though this is not always true. For example, if there are two fish of the same size: one is close to the surface, the other is near the bottom. The fish that is close to the surface has a larger arch because, being closer, more sound waves are returned to the Fishfinder.

The sound waves are actually reflected by an air sac near the center of the fish, not by the body of the fish. The size of this air sac is different for different kinds of fish and this can affect the size of fish arches on the image. A fish with a large air sac produces a large fish arch, while a fish with a small sac produces a small arch. Several arches together show a school of fish. Figure 5-11 shows some example target images.

To display the depth of the fish:

1.Click MENU on the Pathfinder Panel

2.Click TARGET DEPTH ID.

Figure 5-11. Sonar Target Image Key

5-34