GPS May be Unreliable in Large Area of Chesapeake Bay, April-Oct:

The following announcement is from the USCG 5 th District LNM 15/08.

(The GPS Coordinates given below are for the Patuxent Naval Air Station, located on the southern bank of the Patuxent River on the Chesapeake Bay in southern Maryland):

THE GPS NAVIGATION SIGNAL MAY BE UNRELIABLE FROM 01 APR 08 - 31 OCT 08 DUE TO INTERFERENCE TESTING ON GPS FREQUENCIES USED IN SHIPBOARD NAVIGATION AND HANDHELD SYSTEMS. SYSTEMS THAT RELY ON GPS, SUCH ASE-911, AIS AND DSC, MAY BE AFFECTED WITHIN A 35 NM RADIUS OF POSITION 38-15-41N, 076-26-01W DURING THIS PERIOD.

GPS USERS ARE ENCOURAGED TO REPORT ANY GPS SERVICE OUTAGES THAT THEY MAY EXPERIENCE DURING THIS TESTING VIA THE NAVIGATION INFORMATION SERVICE ( NIS) BY CALLING (703)313-5900 OR BY USING THE NAVCEN'S WEB SITE'S 'GPS REPORT A PROBLEM WORKSHEET' AT WWW.NAVCEN.USCG.GOV"