"Peter Duniho" wrote:
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.

The CNX-80 / GNS-480 has it. It's called "Parallel Track". You tell it
if you want to fly left or right of course and by how much (in 1/10's of
a mile IIRC), and it invents a new course line for you to follow.

I believe the Apollo GX-60 had it too. The story I heard was the CAP
wanted to buy a bunch of GX-60's, but insisted Apollo add the Parallel
Track feature to facilitate flying grid search patterns.

Parallel track and the grid search feature are not related to each other.
The GX series has the search grid lines on its display so CAP pilots can
stay oriented in their search grid. But even that wasn't as useful because
the grid lines they did show were not at the correct level. IIRC, you want
7.5 minute grid lines and the GX only showed down to 15 minute grid lines.