I have a fairly new NavPilot 300 installation. It has a SCX-20 for the heading sensor and it's paired with a TZT3 plotter. There is also a Safe Helm 2 installed and I'm using an Octopus pump (PUMPOCT10-12). The boat is a 25' center console with a single 250 outboard using the phantom feedback.
When I first installed the system, it worked beautifully. A while ago when I was offshore it would not hold a course. It would wander all over the place and veer quite far from the track. It would start giving me alarms for being too far off course, but would not correct. I would have to disengage the autopilot and correct manually, only to have it do the same thing again once I reengaged the autopilot. I noticed today that if I put the AP in course hold, the blue line that appears on the chart plotter showing the AP course does not align with the red dashed heading line. There was no current and a light wind at my back. The two lines never come into alignment. I am using precision mode and when holding a heading, I am using the Advanced mode. I did a little research and heard that it may be due to trim tabs being deployed unevenly in a rough sea and it was having a hard time correcting. I recently did some major refitting on my boat which involved replacing the trim tab cylinders and also rebleeding the steering system. Just today, I did a test run after the work was finally complete. It was a 3 month project. Today while running the boat in the intracoastal in very calm water, I experienced the same thing. The boat wanders all over the place and once even made a pretty abrupt turn in the opposite direction of what was required to correct the direction. It seems pretty good at a fast idle speed, but on plane, it is completely useless and I would even say dangerous with that severe turn it initiated. Does anyone have any suggestions on what I should do to troubleshoot? The boat is on a trailer, so it's kind of a lot of work to test it and I have a long distance trip coming up and I was really hoping to be able to use the autopilot during that trip. I will probably only have one chance to get the boat in the water before then. If I can't get this resolved, I will not be able to use the autopilot which will be very disappointing. I would really appreciate some help. Hopefully there is a simple solution.
When I first installed the system, it worked beautifully. A while ago when I was offshore it would not hold a course. It would wander all over the place and veer quite far from the track. It would start giving me alarms for being too far off course, but would not correct. I would have to disengage the autopilot and correct manually, only to have it do the same thing again once I reengaged the autopilot. I noticed today that if I put the AP in course hold, the blue line that appears on the chart plotter showing the AP course does not align with the red dashed heading line. There was no current and a light wind at my back. The two lines never come into alignment. I am using precision mode and when holding a heading, I am using the Advanced mode. I did a little research and heard that it may be due to trim tabs being deployed unevenly in a rough sea and it was having a hard time correcting. I recently did some major refitting on my boat which involved replacing the trim tab cylinders and also rebleeding the steering system. Just today, I did a test run after the work was finally complete. It was a 3 month project. Today while running the boat in the intracoastal in very calm water, I experienced the same thing. The boat wanders all over the place and once even made a pretty abrupt turn in the opposite direction of what was required to correct the direction. It seems pretty good at a fast idle speed, but on plane, it is completely useless and I would even say dangerous with that severe turn it initiated. Does anyone have any suggestions on what I should do to troubleshoot? The boat is on a trailer, so it's kind of a lot of work to test it and I have a long distance trip coming up and I was really hoping to be able to use the autopilot during that trip. I will probably only have one chance to get the boat in the water before then. If I can't get this resolved, I will not be able to use the autopilot which will be very disappointing. I would really appreciate some help. Hopefully there is a simple solution.
Last edited: