[Overtaxed]

I didn't know there was an illustration of an elf ship taking the "straight road."

It took some searching, but I found one! I was looking for elf lighthouses.

[Sam Cree]

Recently, while fishing with a buddy who is a retired physics prof, we were drifting along in his boat (not catching anything) and my mind was wandering around Tolkien's "straight road."

This caused some discussion on where the horizon would be if the world was flat. I think your illustration does a pretty good job of showing where it would be ;^)