the celestial bodies are simulated.
by that i mean, they are there. you can look up and see the dipper or orion's belt for example. and there are the phases of the moon etc.
there is even a mod for somewhat realistic sextant navigation, though i have never given it a go myself.
with that said, the silent hunter series has a few major flaws in regards to realistic navigation of any sort, the biggest in my opinion being that the Silent Hunter World is completely and unashamedly flat. unlike the flight simulators of the era of SH3's release, which simulate a spherical planetary surface. for all the obvious reasons, simulating the spherical surface lends itself to realistic navigation. unfortunately, our SH3 world is flatter than my desk.
this leads to the obvious problems with distance, fuel burn, time to travel etc not to mention the stretching of the northern most and southern most latitudes.
for all the reasons outlined above and a lot more that are not outlined above; the sun, the moon, the stars, etc they are all there, but they are just not exactly in the right positions, unless of course i suppose you play the entire game at the equator where the Mercator projection nature of the SH3 world is least in error. Sadly, the majority of the game's action takes place in the northern latitudes of the North Atlantic, where the "stretching" of the map is not necessarily at its worst, but nearly so.
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