Lowrance X87 Operation Instructions Manual page 62

This series of figures shows how different Grayline settings can reveal
more information. The "A" figures to the left show locations with Gray-
line set at the factory level of 64 percent. At right, the "B" figures show
the same locations with Grayline increased to 84 percent. In Figure 1B,
no fish are near the left structure, but the right structure shows fish
holding next to the structure. Notice in figures 2B and 3B how Gray-
line displays a hard, rocky bottom (the drop-offs) with a wider gray
line. The muddier bottom below those drop-offs appears as a narrower
gray line.
Fig. 1A
Fig. 2A
Fig. 3A
Fig. 1B
Hard
structure
Fig. 2B
Hard
bottom
Fig. 3B
Muddy
bottom
58
Fish near
structure
Muddy
bottom
Hard
bottom
Grayline
Grayline
Grayline