C-Map 4D Chart NA-D931: Lake Michigan (Update)

Why Update Your C-Map Chart? Why Update Your C-Map Chart? It is very important that the latest C-Map charts are used when sailing out in the open water for safe navigation purposes. The C-Map electronic chart libraries get updated twice a year to coincide with popular boating sessions. Included in the library updates are the latest notice to mariner updates from government hydrographic offices, updates to marina facilities, port services, photos and more. Navigational updates to C-Map charts include:  Buoy, beacons and lights. Shoreline areas and shallow water depths. Channels, commercial shipping lanes, and restricted or dangerous areas. Why Exchange Your C-Map Chart? It is recommended to exchange your C-Map chart on your cartridge if you no longer sail or visit the area on the chart to more suitable chart coverage. The exchange process will allow you to receive a brand new chart at the reduced update price. Mail us your C-Map cartridge and we'll exchange the chart on the cartridge