Depends upon what you mean by "water spots on" the screen? Do you mean black, sort of "dead" areas/circles in the LCD screen? I had them on a lapbook that got splashed and called them the "5 moons of Saturn" effect.
I could see the rest of the screen just fine outside the areas of the black "dead" circles. What caused it was water
wicking its way into the space between the glass front plate and rear plate of the LCD screen panel. I looked carefully and the edges of the LCD "sandwich" screen and was not sealed against water intrusion. You would think that the manufacturer would put RTV or something around the LCD sandwich edges, but they don't.
So the idea was to buy a replacement LCD screen but it was not available so the computer was trashed and a new lapbook purchased.