What determines/d the height of a lighthouse?
Intended visual range?
The height is determined by how far from the shore the shallows extend.
How many stones are stacked up to make the lighthouse, and the relative height of each stone.
Curvature of the Earth, the desired distance that it be seen at, and the technology & resources available. The latter not being a trivial issue historically, that’s why the Lighthouse of Alexandria was one of the Classical Wonders of the World. For most of history “how tall can we build it?” was a significant restraint.
So the shallows extending east from North Carolina’s outer banks must go out rather far.
After some googling:
The Diamond Shoals are a cluster of shifting, underwater sandbars that are located just off the coast of Cape Hatteras, but which extend for miles in varying directions, depending on the local currents.
Virtually hidden beneath the waves and always changing formation and depth, the Diamond Shoals are estimated to be responsible for up to 600 shipwrecks along the Hatteras Island and Outer Banks shorelines, earning the region the grisly nickname of the “Graveyard of the Atlantic.”
Throughout the centuries, mariners always ran into several problems when travelling past Cape Hatteras and the Outer Banks. Because the barrier islands off of North Carolina were both low-laying and sparsely inhabited, it was often difficult to see where the ocean waters ended and the shoreline began, especially at night when there were no local town lights to guide the way. Added to this difficulty was the Diamond Shoals, which would be just a few feet deep in some locales, and could easily ground a ship amidst a mix of churning waves and rushing currents.
Thanks for that. I just did a quick scan of Bodie Island Lighthouse and, man, that thing has had the crap kicked out of it over the years (I’m pretty sure it was moved inland sometime since the 1970s).
So how about the craggy coast of, say, Maine?
In my younger years, I went diving off of Hatteras fairly frequently. You can get on a dive boat, cruise out for over an hour, and then dive to 60’ to 70’ and the bottom looks like it does just 50’ from the beach. (Except you do get more sharks and rays.) It’s basically sand…and more sand. Oh, and shipwrecks.
The best predictor of the height of a lighthouse is the height of its parents.
Some have been built too high, disappearing into mist and low cloud. A well known one was Cape Point Lighthouse (South Africa): Built high on a cliff in 1860, it was often shrouded in mist, leading to the wreck of the SS Lusitania in 1911. A new lighthouse was completed in 1919 at a much lower elevation. (Edited- for spelling)
Not to be confused with the better-known Lusitania that was sunk by German submarines in 1915.
Correct, this one was a smaller Portuguese registered vessel and made less of a bang…