Our Advanced Chart Offering Derived from official charts and private sources to provide navigational aids, spot soundings, depth contours, tides and currents, and detailed harbors and marinas Depth Range Shading for up to 10 depth ranges enables you to view your target depth at a glance Up to 1-foot contours provide a more accurate depiction of the bottom structure for improved fishing charts and navigation in swamps, canals and marinas Shallow Water Shading feature allows for depth shading at a user-defined level to aid in navigation Worldwide coverage available Keep your charts up to date with our industry-leading New Chart Guarantee and discount card update program