Jeff is in meetins gettin the new 09 lineup going, so I thought I'd jump in. I work for JB at Navionics.
Try this: Make sure the unit's pages are set up to display mapping.
1) Press 'Menu' button on the unit and scroll down to the 'Map Data' menu
2) Press enter and go to the menu section in this window to make sure it is set up to view the Navionics card. Since Lowrance units can use various other charts, one has to make sure ya tell the unit what manufacturer's card you want to read.
3) Then scroll down to the 'zone' where you want to see the lake (listed by geographical areas).
If that doesn't work, e-mail me at my e-mail address listed with my profile with your phone # and I'll walk ya through the process.
Midwest Regional Sales Manager