G'Day Les,
The manuals all say that but I figure that when I am out & about I will work off my plotter. If the plotter dies then I will be back to compass, chart & parallel ruler, items that I actually have
. Although on the CC the Ray 760 was also very close to the compass & it did not seem to affect it. The mag bearing on the compass was always in synch with the mag reading on the 760. To within a few degrees anyway.
There is only so much room on the dash & there was no way that I would go for an overhead mount as I will be removing the 585 & C80 between trips.