Checking my latest track on RealSpeed I noticed an unusual discrepancy between track point and Doppler of 5 knots on my last run. The sudden surge in the Doppler speed as I pulled up can no doubt be accounted for by the change in satellites and HDOP but what about the rest of the 10s? I am thinking as that part of the track is a short slingshot over mirror flat water with me hiked out almost horizontally to windward the gps is getting a reflected path from the satellites but this does not affect the trackpoint calculation. Any ideas?