From your manual located here:
http://www.lowrance.com/upload/Lowra...071_121704.pdf
This should help you get the detail that you want back on the screen.
Map Detail Category Selection
This menu determines which of the mapping features are shown on the
screen. This includes, waypoints, trails, icons, cities, highways, etc. You
can turn on or off any of these items to customize the map.
To get to Map Categories:
1. From the Map Page, press MENU|? to MAP CATEGORIES DRAWN|ENT.
2. Press ? or ? to select a category or press ? then press ? or ? to select
a subcategory. Press ENT to turn it off (no check) or on (checked.)
3. To return to the last page displayed, press EXIT|EXIT.
And here is Lowrance's number. Give them a call and they'll fix you up.
800-324-1356
8 a.m. to 5 p.m. Central Standard Time, M-F
After doinga little internet research about the Lowrance GPS units, it seems that there was some issues regarding the antennas and having radar interfearence issues.