Heading vs Course at the Dock

[Tigidal]

I have a new to me sailboat that has a Furuno Plotter/Rader (1834). It's connected to the Raymarine AP to get heading data and has a stand alone external Furuno GPS antenna. What I cannot understand is why right now at the dock, the heading in shows the correct number (299M), yet the boat icon on the plotter shows a different direction (about 240M). I wish I could post a photo here, but the plotter is in North Up mode and the its very apparent the difference. Any idea how to correct or if this is how the system should be setup? I cannot leave the dock right now to see if the heading and course are closer when under way, vs when stationary.

 

[Johnny Electron]

Course Over Ground (COG) is not valid unless moving 3 kts or better.
The designed of the Vx2 way back when was for the boat ICON to be by COG. Unlike newer systems that offer a choice to select heading as your ICON source; the Vx2 will always point the ICON by COG.

 

[Tigidal]

Thanks for the quick reply... Does the Furuno unit calculate COG, or is it passed from the Raymarine AP? If the Furuno what data points are considered?

 

[Johnny Electron]

COG is calculated and provided by the GPS unit, whatever that may be.

 

[Tigidal]

Excellent. Thanks again.