The question does not ask about how far can the eye see on a curving surface. The asker stated 'a flat surface' Since when in mathematics do we mix up a flat surface with a curved surface. You have turned a very simple question in to a complicated question by introducing a curved plane.
As one would expect, the further you travel from the Equator, the colder the ocean waters generally become. Near the Equator, surface water temperatures can be as high as 80Â° Fahrenheit (27Â° Celsius). Near the poles, the temperature drops to a chilly 28Â° Fahrenheit (-2Â° Celsius). The western side of oceans are usually warmer than the eastern side. This is due to the way in which both the atmospheric and oceanic currents move water from the equator towards the poles on the western side of oceans, and from the poles towards the equator on the eastern side of oceans.
Much of this deep ocean water is between 0-3 degrees Celsius (32-37.5 degrees Fahrenheit)! It's really, really cold down there! There is a neat program that is measuring the temperature and salinity of ocean surface waters around the world.f you want to know about the temperature of the ocean, you have to learn about the parts of the the ocean first. The top part of the ocean is called the surface layer. Then there is a boundary layer called the thermocline. The thermocline separates the surface layers and the deep water of the ocean.