Coastal explorer vs Garmin heading issues

[Rmlow]

I have all Garmin 7612 mfd’s and recently added a pc based coastal explorer system hoping to use CE as the primary nav system.

The CE system gets all its information from the Garmin system thru a nemo gateway. Currently I’m seeing a consistent 15 degree higher heading on CE than the Garmin mfd shows.

Everything is set to true North on both systems, I verified this several times. I worked with CE tech support and they determined that the 15 degree difference is exactly what is being sent from the Garmin equipment.

To further confuse the issue, although the heading difference shows 15 degrees, in my home waters position is accurate and using visual cues such as range markers verifies heading from the Garmin autopilot.

I’m working with Garmin tech support and sending them logs from the equipment and they are taking it seriously but they have a very slow to response rate to communications.

Have any of you experienced anything similar and if so how was it resolved?

 

[O C Diver]

I have both Garmin and CE. They are generally within a degree or two which also corresponds to my Simrad autopilot.

There are several headings that may come into play.

If you have a heading sensor as a stand alone, that could be a setting.

If you're running a course on autopilot, that's a heading to target.

If you're running on autopilot and fighting a current or wind, the heading may be the boat heading (heading sensor) or the heading based on GPS interpreted course made (past tense).

My first thought would be to determine what both Garmin and CE are using for heading.

Ted

 

[Rmlow]

Both systems use the Garmin heading sensor (fluxgate type)
I’ve allowed for set and drift from wind or current. In all situations there is exactly 15 degrees higher heading number showing on CE. CE got into my system remotely to look at logs and live diagnose.
This is where CE determined the 15* error is coming from the Garmin system. Garmin and CE have discussed and it appears Garmin agrees it’s on their end and have asked for running logs. What’s frustrating is they’ve been incredibly slow to communicate I get an email about every 3 days. We’ve been working the problem for over a month now.

That said both systems appear to be navigating accurately but the 15 degrees difference is disconcerting. Interestingly I also get different depth readings from each Garmin mfd station from the same transducer. Minor but nonetheless different.

 

[tpbrady]

Sounds kind of like something to do with magnetic declination since the fluxgate compass deals with magnetic heading and must add or subtract the declination to get the true heading. If you are near the Portland area the declination is around 15 degrees east, so it’s possibly a math error in the process. How does the heading compare to course over ground?

Tom

 

[Rmlow]

Sounds kind of like something to do with magnetic declination since the fluxgate compass deals with magnetic heading and must add or subtract the declination to get the true heading. If you are near the Portland area the declination is around 15 degrees east, so it’s possibly a math error in the process. How does the heading compare to course over ground?

Tom

Course over ground appears to be ok. I agree (and so does CE) that this is likely related to declination and is some sort of communication error from the Garmin system but so far unsolved

 

[O C Diver]

Interestingly I also get different depth readings from each Garmin mfd station from the same transducer. Minor but nonetheless different.

If the depth readings are consistently off the same amount, could that be the hull offset? Does the transducer connect to one MFD or the NEMA 2000 network?

Ted

 

[Rmlow]

Transducer goes to network. I set the keel offset on the “lead” mfd. I assumed that would apply across all devices but intend to check that today.