Coastal An oceanic site that is located off-shore beyond the tidal mixing zone (estuary) but close enough to the shore that the investigator considers the presence of the coast to be important. Coastal sites typically are within three nautical miles of the shore. Surface Water Sites Adapted from USGS Site Types. http://wdr.water.usgs.gov/nwisgmap/help/sitetype.html ODM2 SiteType Controlled Vocabulary ODM2 Working Group A vocabulary for describing the type of a data collection Site. To some extent, these types represent the ultimate feature of interest that the site was established to measure. For example, a Stream Site was established to measure properties of a Stream.