Notes:

The National Waterway Network (NWN) is a geographic database of navigable waterways and channels in and around the United States, for analytical studies of navigation performance, for compiling commodity flow statistics, and for mapping purposes. The NWN is comprised of a link database and a node database. Links are line strings, which consist of beginning and end points (nodes) with intermediate vertices (shape points). Links represent either actual shipping lanes (i.e., channels, Intracoastal Waterways, sea lanes, rivers) or serve as representative paths in open water (where no defined shipping paths exist). Nodes may represent physical entities such as river confluence's, ports/facilities, and intermodal terminals, USACE nodes, or may be inserted for analytical purposes (i.e., to facilitate routing).