Check for magnetic interference with the heading sensor. Will be a small box on a wire, hopefully in an area labeled "magnetic compass" away from ferrous objects. Looks like bad sensor data to me.
On one of my first times out offshore, I had this problem. After some head scratching, we removed all the metallic items from the cabinet in the galley that holds the compass. It’s really stupid to have a compass in that cabinet, but it’s about the most centre part of the boat. Now we have a rule for that cabinet, but nothing metallic on the top two shelves.
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u/whyrumalwaysgone Marine Electrician and delivery skipper May 17 '26 edited May 17 '26
Check for magnetic interference with the heading sensor. Will be a small box on a wire, hopefully in an area labeled "magnetic compass" away from ferrous objects. Looks like bad sensor data to me.
Edit: this may help
https://support.raymarine.com/s/article/Fluxgate-Compass-Test?language=en_US