C-MAP 4D Chart Cards

A chart card is the difference between your chartplotter's base map and the detailed contours that show where the walleye actually set up. C-MAP 4D cards add full vector chart detail — depth contours, structure, port and marina information — for the waters printed on the card, from the Great Lakes and US coasts to Alaska and Hawaii.

Coverage is the decision. Cards are sold by region in Full and Wide sizes: buy the region that covers your home water completely instead of the cheaper card that clips your favorite lake. 4D runs in Lowrance, Simrad and B&G plotters — if your unit takes the newer DISCOVER or REVEAL X cards instead, those are in C-MAP Discover X / Reveal X, with shaded relief imagery the 4D line doesn't carry.

Card in hand, the plotter does the rest — contour following and route planning features in your unit unlock with real cartography loaded.