Which of the following is not a proof of the spherical shape of the Earth?

Coastal submergence is not a proof of the spherical shape of the Earth. Coastal submergence refers to the phenomenon where the level of the sea rises and covers parts of the coastal areas, due to factors such as tides and ocean currents. This is not directly related to the shape of the Earth, as the same coastal submergence can occur on a flat or any other shaped surface. To prove that the Earth is spherical, evidence such as the ship's visibility (where the hull of a ship disappears from view before the mast), the circular horizon, and the lunar eclipse (where the Earth's shadow on the moon is curved) are more appropriate.