Heading Allignment

[striperstan]

I have a question regarding heading alignment...

System consists of eS128, eS97, EV-200 autopilot, CP-470, RD424 HD radar and SR-150 XM weather receiver, all connected through STng network and Raynet via a HS5 network switch..

All devices have been updated to latest software release as of 8/19.

After installing all equipment and devices, my radar overlay lined up perfectly with Navionics chart data and heading line on chart lined up with visual observation, but heading reading was off by approx. 10 degrees when compared to magnetic compass (adjusted for variation and deviation), and to COG generated by GPS on all headings. I performed an "align to GPS" using the P70R control head, which was successful in that my COG and heading are now in alignment.

After performing the alignment, the radar overlay no longer matched the chart data, so I then used the radar heading offset until the chart data and radar overlay lined back up. My question through all of this is did I perform the proper procedures? Part of me believes that if the alignment (radar to chart) was correct in the first place, then maybe I should not have done the COG/Heading alignment procedure.