This excerpt came of a Marine site, it may be of interest with the thread that has been running. Rob Harrington-Johnson Gypsy Cheoy lee 42 Hong Kong United States Washington, D.C. - The US government has ended the intentional degradation of Global Positioning System (GPS) signals, known as Selective Availability (SA), effective 1 May. As a result, boaters will see marked improvement in the use of GPS equipment. According to a statement from the Department of Commerce, discontinuing SA will improve the predicted accuracy of GPS from within 100 metres (95 percent of the time) to within 20 metres (95 percent of the time). Recreational boaters who use GPS units will now be able to pinpoint their location to within 30 feet instead of 300 feet. "Our 15-year campaign to get the nation's recreational boaters total GPS accuracy has finally paid off and we applaud the president's decision,'' said Elaine Dickinson, BoatU.S. federal government lobbyist. "We are equally glad that the GPS system will continue to be free to all users.'' The decision to discontinue SA is the result of assessments that determined that setting SA to zero at this time would have minimal impact on national security. Additionally, the military has demonstrated the capability to selectively deny GPS signals on a regional basis if US national security is threatened. Civilian users will realize a dramatic improvement in GPS accuracy with the discontinuation of SA. For example, emergency teams responding to a call for assistance will be able to determine what side of the highway they must respond to. The Department of Commerce predicts this policy will help fuel the growth of the global GPS market, currently estimated at over US$8 billion.