From that point of view no simulation ever got any realistic inputs as those would have contained the exact behaviour of water for example.
Everything that can be (economicly) programmed for such simulations are certain rules how an object should behave under certain (ingame-) conditions and even those are very limited.
If we would have an exact physical simulation at the basis everything a developer would need to do would throw a submarine into it and every propellor pulse it would do would have an impact on it's surroundings and itself. THIS would be realistic but that wouldn't produce any playable framerate
.
So everything that gets simulated is just some abstraction from the reality and therefore even most simulation input lacks heavily in detail and the outcome of a simulation are just some rules for everything in it to behave some certain ways. And this is where all the tweeking starts to get it as close to real life behaviour as possible.