First -- Are you sure you have the unit set so that it reads the map chip, and not the factory map???
For info on your card, you need to open the door on the front of the unit and remove the micro sd card.
Who made it? Navionics? Lakemaster?
The new Lakemaster chips will not work in a Lowrance unit.
Not all chips will show contour lines.
For example, Navionics GOLD will only show nautical charts for navigation.
But Navionics PLUS + has the sonar charts and contour lines.
SO check to see that you have a chip that contains the sonar charts.
Go to their website and see if it is upgradeable.
Some of the older ones are not.
Last I heard, they will charge you $100 ??? to upgrade an old card.
In order to update it online, you will need a card reader in your computer.
BUT.... before you do that, consider just buying a new card, as many of the maps have been upgraded to HD in the last few years.
Anther issue you will have to deal with...
You are on the border line of map coverage for different chips.
You may need one chip for the river, and a different chip for Huron.
Best bet before you spend any money, is to check with fellow fishermen in your area, and see what they are using.
Maybe have one of them help you with your unit if you are having trouble.
