NOAA’s Office of Coast Survey directs field programs for ship- and shore-based hydrographic survey units; develops hydrographic survey specifications; conducts technological development and application programs to increase efficiency in survey data acquisition, data processing, and chart production; and carries out research to develop techniques and methods for accomplishing these objectives.To learn more, visit: http://www.nauticalcharts.noaa.gov/hsd/hydrog.htm For information about Patch Test Procedures, see:Specs and deliverables (section 8.1.5.1)Field Procedure Manual (section 1.5.5.1.2)