NorthStar 972 Quickstart Manual And Reference Manual page 115

Bottom lock/center zoom
When you select bottom lock/center zoom,
the flattened-out sea bottom is displayed in
the center of the screen. You can see any
fish near the bottom — as with the bottom
lock zoom — and also examine the seabed's
composition.
Reference Manual Revision B
Bottom lock/center zoom
Marker zoom
When you select marker zoom, you can
choose the part of the water column to
magnify. The top edge of the magnified
area is determined by the location of the
depth marker. To move the depth marker,
press the cursor pad up or down.
Marker zoom
Leaving zoom mode
To return to the normal unzoomed display,
just press Zoom repeatedly until you have
cycled through all the zoom modes.
Reference section 7 — Echo sounding
Zooming in and out
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