COG and Heading differential

[GoFish]

New forum member and new boat owner. I have taken my boat out for a test run since bringing it home from builder. I have tzt3, scx20, navpilot 300. Noticed heading always about 110-120 degrees to the port side of cog (regardless of direction/speed of travel). Builder noted no issues during their installation and testing. I’ve attached pics of my settings. Can I get some ideas where to start troubleshooting? Seems like I should be selecting scx20 where tzt3 is selected on some of these settings? Thanks in advance for your input.

 

[Quirky]

Hi, we put a go to course and followed the line. I assume the degrees on the banner for using a go-to point is based on the chart. When we were aligned with the GoTo point, our heading matched the degrees in the goto banner. But for the last 1247 miles, our COG is irritatingly to starboard (second pic). View attachment 4526View attachment 4527

Hi, we put a go to course and followed the line. I assume the degrees on the banner for using a go-to point is based on the chart. When we were aligned with the GoTo point, our heading matched the degrees in the goto banner. But for the last 1247 miles, our COG is irritatingly to starboard (second pic). View attachment 4526View attachment 4527

Hello There I was just looking at your top photo. I can see that you have a flood tide and that would be consistent with the direction it would be be pushing you boat across the water as seen in your picture. It would be pushing your boat to Stbd which is what your COG is indicating compared to your heading - There could be some leeway thrown in there with wind as well compounding the COG to stbd of your track. When following a course line the key in this case is to alter your heading more to port so your course over ground aligns with the BTW figure at the top of the screen and your dotted red line is in the same line as the course line to your waypoint. Your COG is a moving target and requires constant adjust on your autopilot or helm if you are manually steering to get to the waypoint in the straightest possible way.

 

[jp498]

Position and Cog/sog should be from the scx-20 in the last photo.

 

[DannyAtSowilo]

First step is to see if it is the Heading or Cog that is wrong. I am sure it is the heading but verify it.
Just go with reasonable speed in a known direction - say North and see what COG and Heading say.

The Heading is comming from the physical mounting of the SCX-20 and a soft correction.
Anyhow you have to change the soft correction in the SCX

 

[GoFish]

Thanks for input. I discovered that the pole mount the scx-20 is attached to on the T-top came loose (probably on the cross country trailer ride home from boat builder) allowing the scx-20 to turn facing towards the port side at least 90 degrees which I think is why my heading was always 100+ degrees to the port of cog. Glad it was a simple fix.

 

[gtstang462002]

Thanks for input. I discovered that the pole mount the scx-20 is attached to on the T-top came loose (probably on the cross country trailer ride home from boat builder) allowing the scx-20 to turn facing towards the port side at least 90 degrees which I think is why my heading was always 100+ degrees to the port of cog. Glad it was a simple fix.

Thank you for taking the time to come back and close your issue out on the forum.