I have seen the sunset videos wherein the sun seems to fade away along the horizon, but around the equator it drops straight down behind the curve without any such illusion. As for ships on the horizon, I have a decent lens on my own camera, but I can't personally test the ships 'setting' over the horizon because there's no ocean near me.

Speaking of lenses, there is atmospheric lensing, and the bending of light makes it difficult to know where any celestial bodies really are from down here on the surface. The atmosphere makes a lens, and depending on conditions, will bend light just like a giant spectacle.