Bathymetry for Pamlico Sound was derived from Sixty-five surveys containing 648,402 soundings. Nine older, overlapping, less accurate surveys were entirely omitted before tinning the data. The overlap from eight older, less accurate surveys was omitted prior to tinning. The average separation between soundings was 104 meters. Ten surveys in the southwest dated prior to 1900. The remaining fifty-five surveys used dated from 1913 to 1980. The total range of sounding data was 0.3 meters to -21 meters at mean low water. Mean high water values between 0.1 and 0.6 meters were assigned to the shoreline. Twelve points were found that were not consistent with the surrounding data. These were removed prior to tinning. DEM grid values outside the shoreline (on land) were assigned null values (-32676). Update 2 (10/31/00): Seven additional surveys collected prior to 1900 have been digitized and have been included in the new update. These surveys were in the Pamlico River and at the mouth of the Neuse River, as well as the Wysocking Bay region. The previous update corrected an error in one of the hydro-graphic surveys where feet were registered as fathoms. These soundings were near the mouth of the estuary. No soundings of greater than 21 meters should be present within Pamlico Sound. A vector file delineating the regions were data are inadequate for quality 30m bathymetry have been included in the Zipped files in both Mapinfo [MIF] and ArcView [SHP] formats. NOTE: These updated DEMs are NOT available for the 3 arc second version. Pamlico Sound has seventy-eight 7.5 minute DEMs and four one degree DEMs. The 1 degree DEMs were generated from the higher resolution 7.5 minute DEMs which covered the estuary. A Digital Elevation Model (DEM) contains a series of elevations ordered from south to north with the order of the columns from west to east. The DEM is formatted as one ASCII header record (A- record), followed by a series of profile records (B- records) each of which include a short B-record header followed by a series of ASCII integer elevations (typically in units of 1 centimeter) per each profile. The last physical record of the DEM is an accuracy record (C-record). The 7.5-minute DEM (30- by 30-m data spacing) is cast on the Universal Transverse Mercator (UTM) projection. It provides coverage in 7.5- by 7.5-minute blocks. Each product provides the same coverage as a standard USGS 7.5-minute quadrangle but the DEM contains over edge data. Coverage is available for many estuaries of the contiguous United States but is not complete.