Howdy all,
Looks like this is catching some interest, so I created a tutorial on a simplified method of taking star sights in the game. You don't have to install Python to try this, but do need Stellarium. There are instructions and links for what you need in the tutorial.
SH4 Celestial Navigation Tutorial
Don,
good job on getting this to work on SH3,

I don't have any other versions so it's good to know the savegame files are similar. Take a look at the tutorial, I bet there were times you wished you had a sky as cooperative as Stellarium. I'm almost there. Another 10,000 plots or so and mine will be almost as good as yours.
JBT308 and Pisces,
Welcome to the world of celnav. If you try out the tutorial let me know if it helps understanding, I'm relatively new to this art myself, and getting this working has really helped my understanding of how it works. Don's plots on the previous pages go a long way in explaining some other techniques such as running fixes and proper notation of DR positions on plotsheets. Pisces, just for you I put the time-speed-distance computer on the end of the tutorial. (It's actually a circular slide rule). I was able to write a Python program to generate that directly to pdf.
To all,
Using a Python script to get the sub location out of the game is probably overkill, but I already had it and have used Python for some other projects. It is a powerful and fairly easy to learn free programming language, and there are many tutorials for Python on the web.
Cheers,
Mike