U.S. Geological Survey Open-File Report 2011-1184
High-Resolution Geophysical Data From the Sea Floor Surrounding the Western Elizabeth Islands, Massachusetts
SI to Inch/Pound
Vertical coordinate information is referenced to mean lower low water (MLLW) [the average of the lower low water height of each tidal day observed over the national tidal datum epoch].
Horizontal coordinate information is referenced to the World Geodetic System of 1984 (WGS84) in a Geographic Coordinate System.