Well described, Harbrimar. Your drawing makes it quite clear.
Untill recently it was a slightly different matter in the UK and full size could fly as low as they wanted as long as it was spaced 500ft (horizontaly, verticaly or at an any angle) from any vehicle, structure or building, in other words if you were over water with no boats, lighthouses etc or swimmers within a 500ft virtual sphere around your aircraft you could legaly fly at 10 feet if you were daft enough, likewise over a desolate land area.
But we have since adopted (a version of ) the European SERA 500ft rule, which to my understanding is as you have illustrated
thanks for posting the clear drawing