In article , "Peter Duniho"
writes:

I haven't heard of a GPS unit that allows the user to set some sort of
"offset" from a course to follow, but it wouldn't surprise if such a feature
did exist somewhere.

I never thought of it till you mentioned it but I have that in my 430/autopilot
combination(Piper Autocontrol III). The plane basically follows the heading
bug with the 430 giving correction up to about 30 deg. With the heading bug
offset about 10 deg, the course will be about one dot in that direction and
parallel to the intended course. Happens because the 430 needs an error to
produce a correction. This will happen on its own on a long leg due to DG
drift. Now I know why it's a good thing.

Chuck