cemiii
My unit is before ContourXD, I think it has contour lines whereas the older unit did not. Below is the information from Humminbird's site also below that is their video about it. I hope it helps.
Basically until you actually use a unit on your lake you will not know if it is good enough for you. Probably at some point you may want to purchase a card.
"We’ve upgraded our free, built-in cartography software on the 700, 800, 900 and 1100 Series™ Combo models. All-new ContourXD™ by Navionics® is an enhanced, professional mapping package. With over 3,000 U.S. lake maps in the database, you will be able to find a lake close to any location you might want to wet a line. As an added bonus, ContourXD™ maps will feature depth contour lines, so you can find all the drops, bumps and channels holding fish. The maps will also include U.S. lights/markers, and major roads and interstates. Fish like a pro on your home lake, or a lake far from home, thanks to Humminbird® ContourXD™"
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