VERT_CS["Guam 1963 height",
    VERT_DATUM["Guam Vertical Datum of 1963",2005,
        AUTHORITY["EPSG","1122"]],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["Gravity-related height",UP],
    AUTHORITY["EPSG","6639"]]