I have a Lowrance, and you can either use the Navionics cards, or the NauticPath. I personally have the Chesapeake Bay region Navionics XL3 card in my LCX MT-15. When I bought the boat in 2004, I seemed to be the only gane in town, and cost around $199.00 from cabela's. I have found them to be pretty accurate. It wasn't till after 2004 that I heard about the Nautic Path charts. The Nautic Path charts can be had for around $100.00 I believe.