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hynespa

While on a trip back from Catalina Island this weekend, I had the autopilot engaged in track mode, while I was navigating to a waypoint about 38 miles away.

Three times during the trip (all during the first 30 minutes of a 2.5 hour trip) the autopilot threw the rudder hard to port causing the boat to make a counterclockwise 360 loop while at cruising speed (14-15 kts).

This happened to me on a previous voyage back in May while the autopilot was in track mode following a route made up of multiple waypoints. That time I immediately put the autopilot in "Standby" mode and took control of the steering.

This time I let it go because I was in open water with no other boat traffic and I was curious if it would have the boat continue to do 360's. It only did one complete 360 before the autopilot automatically resumed course.

During the beginning of the uncommanded 360 the autopilot indicator showed the rudder hard to port. Then as the 360 continued the autopilot display changed to only showing "off course". As the 360 concluded it showed me back on course to the waypoint. The three different 360's I experienced were all in the first 30 minutes of the trip ... and were spaced about 5-8 minutes apart from each other... and they were all to port. After the last one the autopilot successfully navigated me to the waypoint in track mode over the next 1 1/2 hours without any more 360's.

I have attached a PDF diagram showing how my autopilot is wired to the MFD. I have the following:

* Raymarine S3G Course Computer
* Raymarine P70R Autopilot Controller
* Raymarine eS127 MFD

NOTE: The heading displayed on the autopilot controller is almost always 15-20 degrees off from the heading displayed on the MFD. I have gone through the autopilot calibration steps outlined in the P70R manual (e.g. the steps that involved driving the boat in slow circles) but the course displayed on the controller still doesn't match the course displayed on the MFD ... or soon goes back out of sync.

Happy to provide you any diagnostic information / logs / etc from the MFD if that would be helpful? You will just have to provide me instructions on how to generate / export these. Please let me know any other troubleshooting steps, etc. Thanks!!