http://www.mapmytracks.com/ en Copyright 2008 2008-12-04 http://www.mapmytracks.com/explore/track/around-the-island/356 Hi Zsolt. What was the weather like during your run? Many factors can affect the accuracy of GPS signals: The number of satellites the unit is connected to; their relative distribution in the sky; local RF interference; signal strength; atmospheric conditions. In my experience, accuracy can sometimes be reduced in bad weather. But don’t be too hard on your SiRF, your cycling tracks look great! 2008-01-24 {screen_name} http://www.mapmytracks.com/explore/track/around-the-island/356 Hi! I agree, it was probably an unlucky attempt. The weather was not bad. There were hardly any clouds. Probably the number of satellites was low and they were in a low position. It is interesting that in both laps the inaccurate part starts at the same place. We were actually running along the river bank. 2008-01-25 {screen_name} http://www.mapmytracks.com/explore/track/around-the-island/356 Looking at your track in different map views, it seems more accurate not on the satellite view - which may point to the inaccuracy being Google. 2008-01-25 {screen_name} http://www.mapmytracks.com/explore/track/around-the-island/356 Actually the satellite view seems very accurate at the start and then went under the road coming from the bridge. It is still fine on the NW part. On the way back we did not run on water of course. :) 2008-01-25 {screen_name} http://www.mapmytracks.com/explore/track/around-the-island/356 Very respectable distance! :) Congratulations! 2008-03-27 {screen_name} http://www.mapmytracks.com/explore/track/around-the-island/356 Kösz! It is only half of a half marathon. :) 2008-03-27 {screen_name}