Outage information is shown next to each site. It is requested that users notify the Navigation Information Services Watchstander at (703) 313-5900 or via email regarding any observed outages, problems, or requests.

The U.S. Coast Guard DGPS service is available for positioning and navigation. Users may experience service interruptions without advance notice. U.S. Coast guard DGPS broadcasts should not be used under any circumstances where a sudden system failure or inaccuracy could constitute a safety hazard. Differential corrections are based on the NAD83 (2011) position of the reference station (REFSTA) antenna. Positions obtained using DGPS should be referenced to NAD 83 coordinate system only. All sites are broadcasting RTCM Type 9-3 correction messages.

**Note that NAVCEN is in the process of updating the integrity monitor positions from NAD83 (CORS96) to NAD83 (2011).

Please report DGPS problems or outages at our report-a-problem page. Thank you in advance.