NorthStar Navigation NorthStar 8000i - Manual (Page 109)

Northstar 8000i Operation Manual 109
You can use the zoom range shift to move the zoomed area up or down to
magnify any section of the water column between the bottom and the surface.
To adjust the zoom range shift:
1. Display the Sounder screen and the control panel. If you can't see the
Range, Zoom and Split button, select Return.
2. Select
Range, Zoom and Split.
3. The
Zoom Range Shift button shows the current setting. Select
the button if you want to change the setting.
Select:
ƒ
Shallower to zoom a different part of the water column, closer
to the surface
ƒ
Deeper to zoom a different part of the water column, closer to
the bottom
4. The new setting is applied immediately and stays until you change it
again. Select OK to confirm the new setting.
16.16 Select a split bottom lock screen
Split bottom lock ensures that the bottom is always shown on the Sounder screen,
regardless of any changes in depth.
You can use the split bottom lock screen to zoom in on the bottom so that you can
easily compare different echo strengths. This can be helpful if you're trying to
identify the type of bottom or locate objects on or close to the bottom.
To show and adjust the split bottom lock screen:
1. Display the Sounder screen and the control panel. If you can't see the
Range, Zoom and Split button, select Return.
2. Select
Range, Zoom and Split. The View Mode button shows
the current setting.
3. Select the button if you want to change the setting and a drop down
list of choices appears.
4. Select
Bottom. The Sounder screen changes to show:
ƒ The history in the right hand side with the bottom always in view
ƒ The zoomed area of bottom in the left hand side
ƒ The numbers at the top and bottom of the zoomed area show the
extent of the zoomed area of bottom. The lower number may show
a negative reading, indicating that this area lies within the bottom.
5. When you are finished, select Return.
NOTE: If the A-scope is already shown, this will also be shown on the split screens
too.
16.17 Change the ratio of a split screen
You can use the split screen ratio to adjust the sizes of a split screen.