Due to new cartographic production processes and the availability of digital products such as Electronic Navigational Charts (ENCs), the Coast Survey Development Laboratory (CSDL) is supporting OCS' Chief Geographer in developing improved techniques for generating more accurate, digital maritime boundaries. Through the use of Geographic Information Systems (GIS) software such as CARIS' LOTS and ESRI's ArcGIS, CSDL will provide NOAA cartographers and the public with the latest vector representations of these boundaries.
In our effort to create digital boundaries, we are utilizing CSDL's Extracted Vector Shoreline from the largest scale nautical charts. This MLLW line is used as input to CARIS' LOTS: Limits and Boundaries software for the designation of a baseline. Once the boundaries are created, they are exported to a text file as a series of points with .1 nautical mile spacing.
Digital boundaries of the Three Nautical Mile Line, Territorial Sea, and Contiguous Zone for the Northwest Hawaiian Islands are contained within a zipped file. Within the zipped file are shapefiles. The shapefiles are polylines which were created by connecting the points exported from the LOTS environment.
The resulting boundaries were attributed in CARIS and exported using the "Output as a Text File" tool. The line was exported as a series of points .1 nautical miles apart in decimal degrees. This point file was parsed to be tab delimited, brought into ArcView 3.2, and converted to a shapefile. The point shapefile was converted to a polyline using the XTools extension.