I just recently bought and installed a Humminbird 998c SI Combo unit. The only maps I have are the basic ones that came already installed on the unit. I am of the opinion I need to add something like the Navionics chip which gives more detail and more information. I would appreciate you guys sharing your opinions as to which is the best one to buy for use in central Arkansas. Are lakes like Nimrod, Harris Brake, Overcup and Brewer on there? Navionics vs. LakeMaster? Thanks for any help you can give me.

Ski