G
Guest
Guest
I am trying to calibrate a new Raymarine log. The manuals no longer explain the old way of doing it (by sailing a known distance and comparing to the trip reading), they only give the method of setting the GPS speed to be the speed of the log.
BUT when I tried this, and checked the result by sailing a known distance, the log now gave too high a distance, indicating that the calibration factor was wrong. I re-calibrated the old way, to get distance correct, and now I find a 0,3 - 0,5 kts lower speed reading on the log than on the GPS.
I recall, on my previous boat, that the GPS often showed a higher reading, and that log was calibrated spot on, which had been tested by sailing thousands of miles.
Has anyone else noticed this discrepancy ? Is there a "theoretical" explanation for it ?
Regards,
Andreas
Andreas
BUT when I tried this, and checked the result by sailing a known distance, the log now gave too high a distance, indicating that the calibration factor was wrong. I re-calibrated the old way, to get distance correct, and now I find a 0,3 - 0,5 kts lower speed reading on the log than on the GPS.
I recall, on my previous boat, that the GPS often showed a higher reading, and that log was calibrated spot on, which had been tested by sailing thousands of miles.
Has anyone else noticed this discrepancy ? Is there a "theoretical" explanation for it ?
Regards,
Andreas
Andreas