gCaptain - Latest Comments in AIS &#8211; Check your GPS Offset For Errorshttp://gcaptain.disqus.com/A blog about ships!enSat, 01 Dec 2007 20:06:59 -0000Re: AIS &#8211; Check your GPS Offset For Errorshttp://gcaptain.com/ais-check-your-gps-offset-for-errors/#comment-1342744<p>Maybe the waypoints listed on the ship's log were in the wrong datum. Perhaps the coordinates listed are in NAD-27 and the ship's GPS uses WGS-84. There might be an error in the north reference, with the captain reporting magnetic and AIS reporting true bearings, a 17-degree difference. There was a report of the captain being unfamiliar with the ship's navigation equipmant, which should be standardized.</p>Thomas BaileySat, 01 Dec 2007 20:06:59 -0000