Furuno TZT9 Operator's Manual page 161

7. FISH FINDER
Bottom lock display
The bottom lock display provides a compressed normal picture on the right half and a
7 to 400 feet (2 to 120 meter) wide layer in contact with the bottom is expanded on the
left half. This display helps you separate the fish near the bottom from the bottom
echo. You can select the bottom lock range with [Bottom Lock Range Span] in [Sound-
er] of the main menu.
Zoomed
school of fish
Bottom zoom display
The bottom zoom display expands the bottom and the fish near the bottom according
to the zoom range selected on [Zoom Range Span] in [Sounder] of the main menu.
This display helps you find the density of the bottom. A short echo tail normally indi-
cates a soft bottom (sand bottom, etc.). A long echo tail indicates a hard bottom.
Bottom
7-4
Bottom lock display
156 300
BL LF
Bottom shown as a straight line
Bottom zoom display
156 300
BZ LF
Single freq. display
Single freq. display
Zoom marker
School of fish
Zoom marker
This area zoomed
and displayed on
left 1/2 of screen.
Zoom marker
automatically
follows change in
depth.