So people will now learn to try and avoid fighting at altitudes where your propeller would dip the water surface.
Better eye-candy, plus, better situational realism, too.
I call this a win-win scenario.
(ps) There's a little something called "altimeter" in your plane. It looks like a clock and corresponds to your climb/dive movement. Perhaps its a good idea to actually use these thingamabobs, since someone obviously took a lot of time to install one of it in your plane.
(ps2) Also, there is another something called "instrument flight". Apparently, it seems that real life pilots also get confused about at which alt they are actually flying at, especially when visuals are impaired due to weather conditions, or does not provide enough relative markers to get an accurate perception of altitude - typically over large surface of water, desert, or plains, at which the lack of visual markers and a grand repetition of dull, singular terrain often fools people. Therefore, people are trained to read the thingamabobs called "altimeter"s, which, remind you, look like a clock.
So it's probably a good idea to look at those stuff before trying stupid things like pulling a split-S over water at dangerously low altitudes.