about GMT: I made some custom missions and (I think
)found out:
-normal time (time shown without mouseover) is GMT, mouseover time is sh3 timezone time. they start at 7°30' from 0° and are 15° wide. gmt and local time don't change when saving/reloading.
-when going west, the game simulates the earth's rotation pretty well, I could pinpoint my location to about 15nm just by using the charts for sunrise/sunset provided by vanjast. given the fact that i can't measure seconds and the sun's upper limb is not always easy to discriminate I find this quite good
-when going east on the other hand, things are different. I was as far as 25°E and my local sunrise occured 25 min earlier then it was supposed to at 0°
<-- should have been 1h40min if I'm not mistaken. --> it is completly unfeasible to use the ingame sun to determine local apparent noon when going east
I ended up with the following plan for real navigation (one reason: current career in the med):
save a game at approxiomately local noon, run don1reed's python script and enter a gmt time that I reason to be before my local noon, go to stellarium and do a noon sight. this works
a little bit of cheating because stellarium has a fixed position and the time entered doesn't change my position etc., but IMHO the best way to go. maybe I'll even try 3 star fixes, but no idea how. maybe using nautictools.de, altough I'd rather like to at least try to do the numbercrunching on my own...