[Salamander]

https://www.howitworksdaily.com/how-high-do-you-have-to-go-to-see-the-curvature-of-the-earth/

[philman_36]

However, you can detect the curve of the Earth from ground level at the coast with a pair of binoculars – just look for distant ships on the horizon and you’ll see that their hulls start to disappear before their masts and other superstructure.

HAHAHAHAHAHA...that's what people are disproving with their P900's!

Naked eye, binoculars and then strong zoom lens.
Each time you increase magnification you can still see the hull!

Want a video or can you find one?

I'll give you this in the mean time...Nikon P900 Superzoom: Flat Earth and The Invisible Lake Pontchartrain Causeway