http://www.boatdir.com/articles en-us http://www.boatdir.com/articles N/A info@submitzoo.com Sun, 20 Jul 2008 08:41:44 CDT 20 http://www.boatdir.com/articles/articles/19/1/GPS-Limatations Low speed velocity calculations by GPS are suspect due to Selective Availability errors. John Holtrop Mon, 16 Jan 2006 00:00:00 CST http://www.boatdir.com/articles/articles/9/1/GPS-For-Boating-Fishermen Using Available Technology to Your Advantage. Joseph J. Breunig 3rd Wed, 30 Nov 2005 00:00:00 CST