Hi all,
We have done a check of heading comparison between our compass and the GPS heading from our autopilot and chart plotter. They have never been in agreement, usually a difference of 10 degrees or more. No problem because we always would make our destination, but thought it would be nice to have the entire boat heading the same way. The marina tech asked me to check for any offset in the autopilot settings which I hadn’t done since the upgrade seven years ago. It was minus 8 degrees. I noted that and slowly returned it to zero.
Yesterday we went out and followed the eight points of sail by the autopilot and logged it within five degrees + or - with the compass. We did reduce the dry weight of the boat when we replaced the old genset with a new one that was 600 pounds lighter. It is probable that this could have influenced the compass which may have to be swung a some point. I thought I should wait until I could check again against other electronics having GPS headings (like the iPad). Or I could wait until the poles are done shifting.
We have done a check of heading comparison between our compass and the GPS heading from our autopilot and chart plotter. They have never been in agreement, usually a difference of 10 degrees or more. No problem because we always would make our destination, but thought it would be nice to have the entire boat heading the same way. The marina tech asked me to check for any offset in the autopilot settings which I hadn’t done since the upgrade seven years ago. It was minus 8 degrees. I noted that and slowly returned it to zero.
Yesterday we went out and followed the eight points of sail by the autopilot and logged it within five degrees + or - with the compass. We did reduce the dry weight of the boat when we replaced the old genset with a new one that was 600 pounds lighter. It is probable that this could have influenced the compass which may have to be swung a some point. I thought I should wait until I could check again against other electronics having GPS headings (like the iPad). Or I could wait until the poles are done shifting.