Originally Posted by
John Alcock
If, for example, a pilot were over sparsely populated Scotland, or the sea, would he be operating illegally if he flew at less than 500 ft above sea level?
Nope.
You are absolutely correct. The 500ft rule only applies to 'people or things containing people' (essentially). If there aren't any 'people or things containing people' (and you can be sure of this), then LEGALLY you can fly as low as you like. (The 500ft is NOT with reference to AGL.)
Now, if it's PRUDENT to fly that low, well that's a completely different kettle of fish!