The US Coast Guard issued a rule updating the listed coordinates of boundaries of the Hampton Roads anchorages to utilize the North American Datum 1983 (NAD 83), rather than the older North American Datum 1927 (NAD 27). The actual locations of the anchorage
s are not being changed, merely the regulatory designation. This change, which comes into effect on March 3, will conform the regulatory standard to that used in modern charts and in GPS.
Source: HK Law