Chuck,
Yes, I think you probably have a good point re. navigating across the Sahara, or the open ocean. My comments are limited to my own experience, which consists of flying around urban areas such as south-east England, or mountainous areas such as Arizona, where there are plenty of visual navigation features.
The only time I've ever been glad to have a navigation aid available as a backup was when flying across eastern California in a sand-storm, with visibility of about 8 miles - although I could still make out the shapes of moutains vaguely through the sand, there were no good navigation featuers, and it was nice to have a VOR/DME to confirm that I was on track and on time. I didn't have a GPS in my aircraft that day, but if I had, I probably would have used it, since it would have been more accurate than the VOR.
Like any tool, GPS can be useful, although I still believe it's overrated and can be detrimental to VFR flying in some cases.
Biker Pilot, I think you must have the same GPS database as me - but since I don't use it much, the errors don't really bother me!
FFF
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