Thank you Thork.
But what does "see" mean? You say you may be able to SEE something in the right conditions, but are we talking about a large ship, or looking at a another person?
If weather conditions were perfect, with low particle density and maximum view distance, how far do you think you would be able to see another man, whether he be identifiable or just a dot? For my purposes I don't need to be standing on the sea shore; imagine you're standing on a flat featureless surface that goes as far as the eye can see - how far could you see another man before he's little dot becomes indistinguishable from the horizon? Are we talking about 50 miles in this scenario?
This is why I was look looking for that old view distance chart, it told you how far you could see an object according to its size, and your height.