Matt Ashbrook wrote:

Just wondering...on the oceans, navigators use a sextant for out of
sight of land navigation. How is it done on the Great Lakes where
they're not operating at sea level? Of course, I'm talking about the
absenceof electronics. Anyone know of any literature on this?

Thanks,
Matt A.

The answer is simple: They don't need to be at sea level
The actual difference in angle to any stellar object would be measurable,
but not with a sextant. Not with these small differences in height.

Peter
--
"Outside of a dog, a book is a man's best friend: and inside a dog,
it's too dark to read." -- Groucho Marx