The littoral zone is defined as the Coastal sea areas and that portion of the land which is susceptible to influence or support from the sea. The extent of littoral zone can vary widely depending on the customer, but generally it extends from the shoreline to the 200 meter depth contour out into the water and from the shoreline inland to the first major line of communication. Other, broader definitions of the littoral zone would have the zone extend from 25 nautical miles seaward to 25 nautical miles inland.
The littoral Zone is divided into three parts; the nearshore, foreshore and backshore zones. The nearshore is the region between the low water line (sounding datum) and the offshore region; the foreshore is the region from the low water line to the high water line; and the backshore is the region of the littoral zone beyond the high water line.
The standard littoral product produced by NGA is the Combat Chart. The chart is in hardcopy only and has been produced by NGA and its predecessor agencies for decades. It is generally at a scale of 1:50,000 and combines the portrayal of a 1:50,000 standard topographic line map with the maritime features displayed on a harbor and approach chart and the area covered by the chart is half land, half water. The main uses of these charts are for planning, amphibious operations and non-combatant evacuation. Recently NGA has begun producing the Littoral Planning Chart. It is similar in scale, content, and intended use to the Combat Chart, but uses more pictorial symbols and is available in PDF format.
Larger scale (1:25,000 or larger) mission specific graphics are also produced by NGA. The content and scale of these graphics are dependent on customer needs and can vary greatly. They can also be provided to the customer in paper or raster versions.