Summary

GPS-derived positions often are of higher accuracy than the positions for charted data.  Navigators should be aware of all the factors that may affect the use of GPS positions when plotting on nautical charts.  Based on this knowledge, the prudent mariners should pass charted hazards such as shoals or isolated dangers with utmost caution and at a safe distance, no matter what navigational method is used.

If apparent conflicts between charted features and GPS-derived positions are observed, please notify the National Ocean Service or U.S. Coast Guard.

Director, Office of Coast Survey N/CS5
National OceanService
1315 East-West Highway
Silver Spring, Maryland
20910-3282