d. all of the water in-between including the shore and the base of the lighthouse visible in the viewfinder,
Speaking of which, why do lighthouses tend to be built on tall cliffs/rocks and tend to be tall towers? Doesn't make sense on flat earth.
So the confusion in your mind (implied but not established) about how perspective works somehow discredits a horizon greater than ten miles away, when it can only be three on a globe?
None of this perspective bullshit matters for a lighthouse. On flat earth you would have a direct line of sight to the light on top of the lighthouse whether it's placed right on the beach or 100 feet above sea level.
Seems like people hundreds of years ago figured out something that you still can't grasp today. Yes, I know, oven, rope, etc. Can I jump off a cliff next to a lighthouse?
Would you not want the light house to be up high no matter if you were on the globe or plane? For example, take a light pole in the distance, it appears to shrink and the light at top would get nearer and nearer the ground the further away you were from it. This happens on a ball or a plane. With water swells, waves and such would it not be an advantage for the lighthouse to be high in both situations? You would also be able to see the lighthouse from further out in both situations the higher it is.